(NZE) Retrofit Strategies of Buildings Envelopes in Gaza, Case Study: Multi-Storey Residential Buildings

الجـامعــــــــــة اإلســـــالميــة بغــزة The Islamic University of Gaza عمادة البحث العلمي والدراسات العليا Deanship of Research and Postgraduate

كـليـــــة الهندســــــــــــــــــــــــــــــــة -Faculty of Engineering

ماجستير –هندسة معماريـــــــــــــــــة Master of Architecture Engineering

Net Zero Energy (NZE) Retrofit Strategies of Buildings Envelopes in Gaza, Case Study: Multi-Storey Residential Buildings

استراتيجيات الطاقة الصفرية في إعادة تأهيل أغلفة المباني في قطاع غزة، حالة دراسية : مباني سكنية متعددة الطوابق

Arch. Rania Mohammad Ashour

Supervised by

Prof. Ahmed S. Muhaisen Dr. Suheir Ammar Sustainable Architecture Social Housing

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Architecture

April / 2018

إقــــــــــــــرار

أنا الموقع أدناه مقدم الرسالة التي تحمل العنوان:

Net Zero Energy (NZE) Retrofit Strategies of Buildings Envelopes in Gaza, Case Study: Multi-Storey Residential Buildings

استراتيجيات الطاقة الصفرية في إعادة تأهيل أغلفة المباني في قطاع غزة، حالة دراسية مبانى سكنية متعددة الطوابق

أقر بأن ما اشتملت عليه هذه الرسالة إنما هو نتاج جهدي الخاص، باستثناء ما تمت اإلشارة إليه حيثما ورد،

وأن هذه الرسالة ككل أو أي جزء منها لم يقدم من قبل االخرين لنيل درجة أو لقب علمي أو بحثي لدى أي

مؤسسة تعليمية أو بحثية أخرى.

Declaration

I understand the nature of plagiarism, and I am aware of the University’s policy on this. The work provided in this thesis, unless otherwise referenced, is the researcher's own work, and has not been submitted by others elsewhere for any other degree or qualification.

Student's name: اسم الطالب: Rania Ashour

Signature: التوقيع:

Date: التاريخ: 09/04/2018

Abstract

Over last decades, maximizing the energy savings in the existing buildings was a challengeable issue that enabled the engineers to achieve the sustainability principles. These principles depend on using less fossil fuel for meeting the heating and cooling demands of the buildings. Net zero energy is a term of achieving high-energy performance that should be covered on-site generation by renewable sources. The buildings should be able to reduce their energy demands through their envelope components. Although sustainability principles are poorly applied on Gaza buildings, there is a hope to fulfill the high-energy performance through their envelopes. This represents a guide for architects to produce energy efficient buildings in the presence of shortage in the electricity sector, especially that, there is only one supplier plant to Gaza areas. Therefore, these buildings can cut down greenhouse gas emissions. In this context, the stock of the existing buildings in Gaza could not be ignored as there is a chance to improve their thermal performance. So, this study aims to identify the Net Zero energy retrofit strategies that could be applied to the building envelopes in Gaza. In order to achieve this aim and the objectives of the study, the study based on the descriptive analytical method. An experimental approach is conducted by using DesignBuilder V5 simulation tool that applies many scenarios that can be applied to achieve NZE principles to improve the thermal performance of existing multi-storey residential buildings in Gaza. The outcomes showed that low thermal transmittance for the envelope components, and low shading coefficient for fenestration systems with mixed mode ventilation could get low energy consumption buildings. The combination of double skin facade and vertical greenery systems (GDSF) was an effective strategy for ventilation whether as a passive or active due to its ability to improve indoor air quality. Also, about 80% of energy savings was achieved. The building produced an energy as a surplus that should be weighted and credited. The cost-optimal solution achieved by less net site energy. If pay pack were 11 years, the cost will be 1436 GBP in a month. The study recommendations are as strategies that may benefit decision makers, architects and owners in Gaza to get NZEBs.

Keywords: net zero energy retrofit, building envelope retrofit, energy performance, and energy savings.

III

Abstract in Arabic

يمثل توفير الطاقة في المباني القائمة تحديًا كبيرًا للمهندسين على مر العقود الماضية، وال سيما أنه يمكنهم من تحقيق مبادئ اإلستدامة عن طريق تقليل إستخدام الوقود األحفوري في تأمين متطلبات التدفئة والتبريد في تلك المباني. ويطلق مصطلح مباني الطاقة الصفرية NZEB على المباني التي تحقق كفاءة الطاقة من خالل توليد الطاقة بواسطة المصادر المتجددة وبالتالي تقليل إعتماده على الوقود األحفوري؛ وذلك من خالل التحكم بمكونات أغلفة المباني. ورغم أن قطاع غزة يفتقر الى آليات تطبيق اإلستدامة في مبانيه ، إال أنه هناك أمالً في تحقيق كفاءة الطاقة من خالل أغلفة تلك المباني. وهذا يمثل مرجعية للمهندس المعماري إلنتاج مباني كفؤة للطاقة في ظل النقص في إمداد الكهرباء، وخاصةً أنه هنالك محطة وحيدة مغذية للكهرباء في قطاع غزة. وبالتالي تقلل هذه المباني من إنبعاث تاني أكسيد الكربون. في هذا السياق، ال يمكن تجاهل مخزون المباني القائمة في قطاع غزة؛ حيث الفرصة متاحة لتحسين أدائها الحراري. لذا تهدف الدراسة الى تحديد إستراتجيات الطاقة الصفرية التحديثية التي يمكن تطبيقها على أغلفة المباني القائمة في قطاع غزة. ولكي يتم تحقيق الهدف الرئيس واألهداف المنبثقة منه، إعتمدت الدراسة على المنهج الوصفي التحليلي. اعتمد القسم التحليلي على استخدام أداة المحاكاة للتحليل الحراري DesignBuilder V5 من أجل تطبيق السيناريوهات الممكنة على أغلفة المباني المتعددة الطوابق القائمة لتحسين أدائها الحراري والحصول على مباني صفرية الطاقة. أظهرت النتائج ضرورة توفير أقل نفاذية حرارية لمكونات غالف المباني، وأقل معامل تظليل ألنظمة الزجاج والتظليل بوجود التهوية المختلطة. كما أظهرت النتائج بأن استخدام المركب للواجهات المزدوجة والواجهات النباتية (GDSF) هي أفضل إستراتجية للتهوية سواء كطريقة خاملة أو فعالة؛ وذلك لقدرتها على تحسين جودة الهواء في الداخل. كما تم تحقيق 80% من حفظ الطاقة باإلضافة الى إنتاج طاقة أخرى فائضة والتي يجب وزنها وتقييمها. والحل األمثل للتكلفة هو أقل طاقة يتم استهالكها في الموقع. إذا كانت فترة اإلسترجاع 11 عامًا، فإن التكلفة ستكون 1436 جنيه إسترليني في الشهر. توصيات الدراسة هي إستراتيجيات يمكن أن تفيد صناع القرار والمهندسين المعماريين ومالك المباني في غزة للحصول على مباني صفرية الطاقة.

الكلمات المفتاحية: الطاقة الصفرية التحديثية، تحديث غالف المبنى، األداء الحراري، توفير الطاقة.

Epigraph Page

) َحتَّ ٰى إِذَا أَتَ ْوا َعلَ ٰى َوا ِد النَّ ْم ِل قَالَ ْت نَ ْملَةٌ يَا أَي َها النَّ ْم ُل ا ْد ُخلُوا َم َسا ِكنَ ُك ْم ََل يَ ْح ِط َم نَّ ُك ْم ُسلَ ْي َما ُن َو ُجنُودُهُ َو ُه ْم ََل يَ ْشعُ ُرون )18( فَتَبَ َّس َم َضا ِح ًكا ِم ْن قَ ْو ِل َها َوقَا َل َر ِب أَ ْو ِز ْعنِي أَ ْن أَ ْش ُك َر ن ِ ْع َمتَ َك الَّتِي أَ ْنعَ ْم َت َعلَ َّي َو َعلَ ٰى َوا ِلدَ َّي َوأَ ْن أَ ْع َم َل َصا ِل ًح ا تَ ْر َضاهُ َوأَ ْد ِخ ْلنِي بِ َر ْح َمتِ َك فِي ِعبَا ِد َك ال َّصا ِل ِحي َن(

القرآن الكريم: سورة النمل آية 19-18

Dedication

To my father’s soul, (May Allah has mercy on him), who was my biggest champion and cheerleader,

To my mother for her love and encouragement, To my beloved sisters and brothers for their long encouragement at every stage, To my nephew and niece, Mohammad, Hamza, Belal, Jana, and Nahla. To the third holiest place in the world AL-Aqsa mosque, May Allah return it back to us.

I dedicate my work.

Acknowledgment

All praise to the Almighty Allah, the one whom all dignity, honor and glory are due to. Whom, this thesis would not have been possible unless his guidance and help. Peace and blessing of Allah be upon our prophet Mohammed. In the first place I owe my deepest gratitude to Prof. Mohammad Ashour (May Allah has mercy on him) who played a major role in encouraging and supporting me during achieving this work until he passed away. Also, I would like to record my gratitude to my supervisors Prof. Ahmed S. Muhaisen and Dr. Suheir Ammar for their supervision, advice and guidance from the very early stage of this research and for giving me extraordinary experience throughout this work. Without their guidance and help this thesis would not have been possible. I am indebted to Prof. Mohammad Kahloot, and Prof. Omar Asfour for their support and caring. Finally, I extend my thanks to the Islamic University of Gaza’s staff for their help and cooperation.

VII

Table of Contents

Contents Declaration ______I Abstract ______III Abstract in Arabic ______IV Epigraph Page ______V Dedication ______VI Acknowledgment ______VII Table of Contents ______viii List of Figures ______x List of Tables ______xiii List of Abbreviations ______xiv Chapter 1 Introduction ______1 Introduction______2 1.1 Research problem ______3 1.2 Aim and Objectives ______4 1.3 Signification ______5 1.4 Limitations ______5 1.5 Previous studies ______5 1.6 Overview of thesis ______9 Chapter 2 State of The Art ______11 Introduction______12 2.1 Background about a net zero energy retrofit ______12 2.2 Net-zero energy building (NZEB) definition ______19 2.3 Net zero energy retrofit of envelope methodology ______27 2.4 Net zero energy retrofit assessment of building envelope ______32 2.5 NZE envelope retrofit technologies ______39 2.6 The reasons for supporting the idea of NZE in the residential buildings sector: globally and locally ______58

viii

Chapter 3 Methodology ______63 3.1 Research design ______64 3.2 Research population ______65 3.3 Target population ______65 3.4 Sampling of floors ______74 3.5 Research tools ______75 3.6 Simulation Tools and Validity ______76 Chapter 4 NZER of the building envelope in Gaza ______78 Introduction______79 4.1 NZE retrofit measures evaluation ______79 4.1.1 U-value ______80 4.1.2 Shading devices SHDs and Shading coefficient SC ______84 4.1.3 Airtightness ______106 4.1.4 Green roof (GR) ______108 Chapter 5 The role of NZER process in improving the ventilation ______111 Introduction______112 5.1 Natural ventilation ______112 5.2 Mechanical ventilation (MechVent) ______154 5.3 Mixed ventilation (MXM) ______160 Chapter 6 RES generation and cost-effectivenees using PV panels ______177 Introduction______178 6.1 Renewable energy source generation RES ______178 6.2 Cost effectiveness ______185 6.3 Challenges and barriers ______188 Chapter 7 Conclusion and recommendations ______189 Introduction______190 7.1 Conclusion ______190 7.2 Recommendations ______194 7.2.1 Recommendations for decision makers: ______194 7.2.2 Recommendations for architects and designers______194 7.2.3 Recommendations for owners, and stakeholder ______196 References ______197 Appendix (01) ______213

List of Figures

Figure (1.1): The structure of the study ...... 10 Figure (2.1): 19th examples of NZEB ...... 14 Figure (2.2): 2005th examples of NZEB ...... 15 Figure (2.3): The Plus Energy housing ...... 15 Figure (2.4): 2007-2009th examples of NZEB ...... 15 Figure (2.5): Results of the NZEB Tools Mechanics ...... 18 Figure (2.6): NZEB relevant terminology ...... 22 Figure (2.7): Renewable energy supply options ...... 23 Figure (2.8): The system boundary of NZEB ...... 25 Figure (2.9): Displays a graph of energy balance for NZEB ...... 27 Figure (2.10): Transforming construction to low energy building ...... 29 Figure (2.11): Examples of multi-objective improvement & assessment of energy demands ...... 35 Figure (2.12): Thermodynamic system of NZEB with the potential of integrating PCM ...... 41 Figure (2.13): Examples of PCM applications into a brick and concrete ...... 41 Figure (2.14): Examples of the solar chimney ...... 42 Figure (2.15): Example of BIST as cladding system ...... 43 Figure (2.16): Example of BIST as a balustrade cladding system ...... 44 Figure (2.17): Envelope applications of BIST ...... 44 Figure (2.18): PVs Silicon based cell...... 45 Figure (2.19): BIPV products ...... 46 Figure (2.20): Diagram of building integrated hybrid photovoltaic system ...... 47 Figure (2.21): Schematic of grid-connected medium power PV systems ...... 47 Figure (2.22): Schematic of working BIPV/T systems ...... 48 Figure (2.23): Examples of BIPV/T systems ...... 49 Figure (2.24): Well-designed DSF integrated efficient energy solutions...... 50 Figure (2.25): PV cells electrically grouped into a vertical stack of three arrays ...... 51 Figure (2.26): The Vertical greenery systems ...... 53 Figure (2.27): A summary of the four sensor types of dynamic window...... 53 Figure (2.28): EC technology in clear and tinted states ...... 54 Figure (2.29): Aerogel glazing ...... 56 Figure (2.30): Passive and active solutions sets for NZEB in hot humid climate ...... 57 Figure (3.1): Al Quds engineers apartment building (QEAB) ...... 66 Figure (3.2): QEAB plans ...... 67 Figure (3.3): Köppen climate classification ...... 70 Figure (3.4): Dry blub temperatures ...... 71 Figure (3.5): Psychometric chart using ASHRAE standard 55-2004 ...... 72 Figure (3.6): DesignBuilder thermal comfort calculator ...... 73 Figure (3.7): The climate consultant solutions offered for the semi-arid climate ...... 73 Figure (3.8): Modelling cases setup ...... 74 Figure (4.1): The effect of applying U value constraints on northern apartments ...... 83 Figure (4.2): The effect of applying U value constraints on southern apartments ...... 83 Figure (4.3): Types of shading devices ...... 85 Figure (4.4): The effect of applying blinds on the AL of L1-SW, L2-SW, and L8-SW ...... 85 Figure (4.5): Dimensions of overhang ...... 87 Figure (4.6): The effect of applying OHs on AL of L1-SW, L2-SW, and L8-SW ...... 87 Figure (4.7): Dimensions of sidefins...... 89 Figure (4.8): The effect of applying a combination of OHs and SFs on ALs of L1-SW, L2-SW, and L8-SW ...... 89 Figure (4.9): Dimensions of louvers ...... 91 Figure (4.10): The effect of applying LOs on ALs of L1-SW, L2-SW, and L8-SW ...... 91 Figure (4.11): The combination of OHs, SFs, and LOs, type (1) ...... 93 Figure (4.12): The effect of applying the combination of OHs, SFs, and LOs (type (1)) on ALs of L1- SW, L2-SW, and L8-SW ...... 94

Figure (4.13): The combination of OHs, SFs, and LOs, type (2) ...... 94 Figure (4.14): The effect of applying the combination of OHs, SFs, and LOs (type (2)) on AL of L1- SW, L2-SW, and L8-SW ...... 94 Figure (4.15): Positions of the typical windows patterns ...... 96 Figure (4.16): Shading coefficient of examined fenestration ...... 97 Figure (4.17): The effect of examined SCs of fenestration on cooling loads and natural ventilation ... 98 Figure (4.18): The effect of examined SCs of fenestration on mechanical ventilation loads...... 99 Figure (4.19): The effect of examined SCs of fenestration on mixed mode ventilation loads ...... 100 Figure (4.20): SC of the examined glazing systems ...... 102 Figure (4.21): Sensible heat gain through no shaded glass by using GLF ...... 103 Figure (4.22): Sensible heat gain through shaded glass by using GLF ...... 104 Figure (4.23): A comparison ST through examined glasses for L5-NE...... 105 Figure (4.24): The impact of thermal break and excellent crack templet on ALs...... 108 Figure (4.25): The impact of implementing green roof on heating and cooling loads ...... 109 Figure (5.1): AT, RT, and DBT of the examined zones (RC) ...... 113 Figure (5.2): FAF of the examined zones (RC) ...... 113 Figure (5.3): heat gain and loss of the examined zones (RC) ...... 113 Figure (5.4): The typical behavior of temperatures, and HGLG, of the examined zones (RC) ...... 114 Figure (5.5): Sun path in summer and winter design weeks using Ecotect ...... 115 Figure (5.6): AT, RT, and DBT of the examined zones in comparison with RC (SHDs)...... 115 Figure (5.7): FAF of the examined zones in comparison with RC (SHDs) ...... 116 Figure (5.8): HLG the examined zones (SHDs) ...... 116 Figure (5.9): The typical behavior of AT, and HGLG of the examined zones (SHDs) ...... 117 Figure (5.10): Wind catcher pattern (WC1)...... 118 Figure (5.11): AT, RT, and DBT of the examined zones in comparison with RC (SHDsWC) ...... 119 Figure (5.12): FAF of the examined zones in comparison with RC (SHDsWC) ...... 119 Figure (5.13): HLG the examined zones (SHDsWC) ...... 120 Figure (5.14): The typical behavior of AT, and HGLG of the examined zones (SHDsWC) ...... 120 Figure (5.15): Double skin façade DSF ...... 121 Figure (5.16): The airflow types of DSF ...... 121 Figure (5.17): AT, RT, and DBT of the examined zones in comparison with RC (DSF) ...... 122 Figure (5.18): FAF of the examined zones in comparison with RC (DSF) ...... 122 Figure (5.19): HLG the examined zones (DSF) ...... 123 Figure (5.20): The typical behavior of AT, and HGLG of the examined zones (DSF) ...... 123 Figure (5.21): Slim type double skin window ...... 124 Figure (5.22): AT, RT, and DBT of the examined zones in comparison with RC (DSFWC) ...... 125 Figure (5.23): FAF of the examined zones in comparison with RC (DSFWC) ...... 125 Figure (5.24): HLG the examined zones (DSFWC) ...... 126 Figure (5.25): The typical behavior of AT, and HGLG of the examined zones (DSFWC) ...... 126 Figure (5.26): Applying GDSF on the QEAB ...... 127 Figure (5.27): AT, RT, and DBT of the examined zones in comparison with RC (GDSF) ...... 128 Figure (5.28): FAF of the examined zones in comparison with RC (GDSF) ...... 128 Figure (5.29): HLG the examined zones (GDSF) ...... 129 Figure (5.30): The typical behavior of AT, and HGLG of the examined zones (GDSF) ...... 129 Figure (5.31): AT, RT, and DBT of the examined zones in comparison with RC (GDSFWC) ...... 130 Figure (5.32): FAF of the examined zones in comparison with RC (GDSFWC) ...... 131 Figure (5.33): HLG the examined zones (GDSFWC ...... 131 Figure (5.34): The typical behavior of AT, and HGLG of the examined zones (GDSFWC) ...... 132 Figure (5.35): SHG. FAF, and HL for SW zone ...... 132 Figure (5.36): Section of the site ...... 136 Figure (5.37): Longitudinal sections of the RC ...... 136 Figure (5.38): Stack effect in multifamily buildings (simplified), showing shaft effects ...... 137 Figure (5.39): Air velocity inside the main shafts of the RC ...... 137 Figure (5.40): AA inside the fifth-floor zones of RC ...... 138 Figure (5.41): Longitudinal sections of the WC1 ...... 139 Figure (5.42): Air velocity inside the main shafts of the pattern 01 wind catcher ...... 140 Figure (5.43): Air velocity and pressure inside the main shafts of the pattern 01 wind catcher ...... 140

Figure (5.44): AA inside the fifth-floor zones of WC1...... 140 Figure (5.45): Systematic concept of WC2 ...... 141 Figure (5.46): Longitudinal sections of the wind catcher pattern 02 ...... 142 Figure (5.47): Air velocity inside the main shafts of WC2 ...... 142 Figure (5.48): AA inside the fifth-floor zones in case of WC2 ...... 142 Figure (5.49): an air barrier compartmentalization concept ...... 143 Figure (5.50): Glazing skylight installed to upper opening of the main shafts ...... 144 Figure (5.51): Longitudinal sections of the glazing skylight ...... 144 Figure (5.52): Air velocity inside the main shafts of glazing skylight ...... 144 Figure (5.53): Age of air inside the fifth-floor zones in case of the glazing skylight ...... 145 Figure (5.54): Air velocity inside the L5-SW of DSF case ...... 146 Figure (5.55): AA inside the fifth-floor zones in case of DSF ...... 146 Figure (5.56): AA inside the fifth-floor zones in case of the DSFWC ...... 147 Figure (5.57): Air velocity inside the fifth-floor zones in case of the DSFWC ...... 147 Figure (5.58): Air velocity inside the fifth floor zones in case of the DSFWC ...... 148 Figure (5.59): Age of air inside the fifth-floor zones in case of the GDSF ...... 149 Figure (5.60): Air velocity inside the L5-SW of GDSF, and GDSFWC scenarios ...... 149 Figure (5.61): Air velocity inside the fifth-floor zones in case of the GDSF ...... 149 Figure (5.62): Age of air in fifth floor ...... 151 Figure (5.63): Thermal mass position into L8-SW floor ...... 152 Figure (5.64): AT and air velocity of RC of L8-SW ...... 152 Figure (5.65): AT and air velocity of thermal mass of L8-SW ...... 153 Figure (5.66): Air velocity of L8-SW (thermal mass case) ...... 153 Figure (5.67): Surface temperature of porcelain and stone ...... 153 Figure (5.68): MechVent loads and their behavior of the examined zones (SHDs scenario) ...... 155 Figure (5.69): HLG the examined zones (SHDs) ...... 155 Figure (5.70): Dc of the examined zones (SHDs) ...... 156 Figure (5.71): MechVent loads and their behavior of the examined zones (DSF scenario) ...... 157 Figure (5.72): HLG the examined zones (DSF) ...... 157 Figure (5.73): Dc the examined zones (DSF) ...... 158 Figure (5.74): MechVent loads and their behavior of the examined zones (GDSF scenario) ...... 159 Figure (5.75): HLG the examined zones (GDSF) ...... 159 Figure (5.76): Dc the examined zones (GDSF) ...... 160 Figure (5.77): MXM loads and their behavior of the examined zones (SHDs scenario) ...... 161 Figure (5.78): HLG through the envelope of the examined zones (SHDs) ...... 162 Figure (5.79): Dc of the examined zones (SHDs) ...... 162 Figure (5.80): MechVent loads and their behavior of the examined zones (SHDsWC) ...... 163 Figure (5.81): HLG through the envelope of the examined zones (SHDsWC) ...... 163 Figure (5.82): Dc of the examined zones (SHDsWC) ...... 164 Figure (5.83): MXM loads and their behavior of the examined zones (DSF scenario) ...... 165 Figure (5.84): HLG through the envelope of the examined zones (DSF) ...... 166 Figure (5.85): Dc of the examined zones (DSF) ...... 166 Figure (5.86): MechVent loads and their behavior of the examined zones (DSFWC scenario) ...... 167 Figure (5.87): HLG through the envelope of the examined zones (DSFWC) ...... 168 Figure (5.88): Dc of the examined zones (DSFWC) ...... 168 Figure (5.89): MXM loads of the examined zones (GDSF scenarios) ...... 169 Figure (5.90): HLG of the examined zones (GDSF scenarios) ...... 170 Figure (5.91): The behavior of HLG through the envelope of the examined zones (GDSF) ...... 170 Figure (5.92): Dc of the examined zones (GDSF) ...... 171 Figure (5.93): AL of MechVent and MXM ventilation ...... 173 Figure (6.1): BIPV-PV and BIPV-PVP cases of RES generation ...... 179 Figure (6.2): PV generation results ...... 182 Figure (6.3): Electric loads satisfied of the examined generation cases ...... 182 Figure (6.4): Total site energy and net site energy of the examined generation cases ...... 183 Figure (6.5): A summary of NZER process for QEAB ...... 187

xii

List of Tables

Table (2.1): Main technical features of residential examples of NZEB ...... 16 Table (2.2): Fundamental aspects of NZEBs ...... 21 Table (2.3): The classification of NZEB ...... 24 Table (3.1): The consumed energy (MWh) by the baseline case ...... 67 Table (3.2): The internal sensible heat gain for each zone ...... 68 Table (3.3): The brief exhibition of the methodology of the study ...... 76 Table (4.1): The examined cases of walls and glazing ...... 81 Table (4.2 ): Thermal properties of the examined walls ...... 82 Table (4.3): Shade line factor (SLFs)...... 88 Table (4.4): The examined glazing types ...... 101 Table (4.5): The examined shading devices with their ID product numbers via W07 ...... 101 Table (4.6): GR specifications as built-in DB ...... 109 Table (5.1): Air velocity versus age of air in fifth floor ...... 151 Table (5.2): MechVent annual loads of RC for the examined zones ...... 154 Table (5.3): Mixed HVAC loads for RC ...... 161 Table (5.4): AL of mechanical and mixed mode HVAC ...... 175 Table (6.1): Electric loads satisfied of the examined generation cases ...... 182 Table (6.2): Multi-objectives of optimization process ...... 185

xiii

List of Abbreviations

AA Air of Age AT indoor Air Temperature ACL Annual Cooling Load AHL The Annual Heating Load AL Annual Load AV AVerage BEER Building Energy Efficiency Retrofit BIPV Building Integrated PhotoVoltaic BIPV/T Building-Integrated PhotoVoltaic Thermal system BIST Building-Integrated Solar Thermal system BLs Blinds CLTD Cooling Loads Temperature Differences CMU Concrete Masonry Units DBT outside Dry Bulb Temperature Dc DisComfort hours DSF Double Skin Façade DW Dynamic Window EE Energy Efficiency EEM Energy Efficiency Measures EQ EQuation FAF Fresh Air Flow rate GDP Gross Domestic Product GDSF Greenery vertical system Double Skin Facade GR Green Roof HGL Heat Gain and Loss HGLG Heat Gain and Loss Graph HLg Heat Loss through glazing HLw Heat Loss through walls

HLE Heat Loss through opening External windows HL I Heat Loss through opening Internal windows HVAC Heating, Ventilating, and Air Conditioning LOs Louvers MENA Middle East and North Africa

xiv

MechVent Mechanical Ventilation MVF Mechanically Ventilated Façade MXM MiXed Mode ventilation NIS New Israeli Shekel (1 USD ~ 3.69 NIS) NREL National Renewable Energy Laboratory NVF Naturally Ventilated Façade NZE Net Zero Energy NZEB NET Zero Energy Building OHs Overhangs OAT Outdoor Air Temperature PCBS Palestinian Central Bureau of Statistics PCM Phase Change Materials PEC Palestinian Energy Code PENRA Palestinian Energy and Natural Resources Authority PV PhotoVoltaic QEAB Al Quds Engineers Apartment Building RC Reference Case RES Renewable Energy Sources RT Radiant temperature SC Shading Coefficient

SCf Shading Coefficient of fenestration

SCG Shading Coefficient of glazing SCH Solar CHimney SF SideFins SHDs SHading Devices SHGC Solar Heat Gain Coefficient

SHGI Solar Heat Gain through the Internal windows

SHGW Solar Heat Gain through the external Windows TES Thermal Energy Storage systems TL Total Load TSW Thermal Storage Wall WC Wind Catcher VGS Vertical Greenery System

Chapter 1 Introduction

Introduction

It is no longer limited; the concept of rehabilitation of buildings has been used to increase the life-cycle of the buildings or to revive the traditional ones through maintaining or upgrading part or parts of the buildings in order to give them lastingness. However, this concept has been developed to include mechanisms that make existing buildings a real effective player in implementing green building criteria. These criteria encompass upgrading energy efficiency and the quality of the external and internal environment. In addition, it improves thermal comfort level for occupants of such buildings. Therefore, the existing buildings have been included in the concept of sustainable development in order to conserve the natural resources (Evangelisti, Guattari, & Gori, 2015). In Gaza, there is an imperative need for guiding architectural production toward energy efficient buildings in the presence of a sequence of crises in the electricity sector. Besides, the sources of generating electricity are unable to meet all the electricity need in Gaza. Despite limited resources, consumed loads have been increased seven percent yearly. In addition, the supplying quantities of fuel needed to operate the power plant are decreasing ( there is only one supplier plant to Gaza areas) because of Israeli restrictions (Palestine Energy and Natural Resources Authority, 2012). Furthermore, using fuel causes environmental pollution which is responsible for global warming now that greenhouse gas emissions. Whereas the stock of the existing buildings in Gaza could not be ignored, there is an urgent need to apply the principles of green buildings on the existing ones to improve the thermal performance. The process is called Green Retrofit or Net Zero Energy Building renovation. Making use of the envelope elements of the building such as doors, windows, floors, and roofs, the chance is possible to reduce energy consumption and greenhouse gases emissions that result from heating, air conditioning processes, and lighting appliances. This makes buildings environmentally friendly and the result will affect human health and their quality of life. One can say that there is a need to integrate energy efficient technologies and renewable energy components to achieve NET Zero Energy (NZE)

in our buildings. Many strategies have been developed to guide this process. So, the study aims to identify the Net Zero energy retrofit strategies that could be applied on the existing building envelope in Gaza multi-storey residential buildings as a case study. In order to achieve this aim, the study uses a descriptive analytical method. The analytical part relies on the DesignBuilder V5 simulation tool.

1.1 Research problem

Over time, Gaza has faced many deep problems. Mainly, the siege and the practices of the Zionist entity in various ways affected the quality of life. In addition, the fuel entering Gaza is insufficient to operate the only power plant. Mindfully, Israel practices lead to wars that come to everything and everywhere. The siege caused slowing of the reconstruction, which led to increasing population density in one area. The strategic stock of the existing buildings has exposed many problems related to the building physics (such as temperature, humidity, lighting) and other problems relating to environmental design (such as corrosion and mold (Sebestyen, 2003). In addition, the hot, dry climate in summer, rainy and cold winter represent a challengeable issue that Gaza people suffer from (State of Palestine, 2016b). Therefore, these problems have burdened the people in Gaza at all levels, whether in providing the suitable environment inside the house by using traditional ways or using of costly electric methods for thermal comfort required. The result is to increase in energy consumption. There is a need to a global technology and techniques for making use of the elements of the building envelope offering an opportunity to achieve the energy efficiency of those buildings resulting Net-Zero-Energy buildings. The research will concern about available envelope strategies that can be used to achieve NZE in Gaza. Precisely, applying some NZE building envelope techniques on Gaza buildings, particularly, multi-storey residential buildings is essential. According to the building current situations in Gaza, the need to provide thermal comfort for their occupants is a crucial, especially, its relation to the implications of the problem of electricity for energy efficiency. The problem of the study is to improve the thermal performance of the buildings by improving the performance elements of the building envelope to obtain the zero-energy. Consequently, to reduce the use of fossil fuel, reducing the heating

and cooling load through what is the building industry has made. So, the problem of the study can be summarized in the following main question: What are the Net Zero energy retrofit strategies that could be applied on the buildings envelopes in Gaza? Many minor questions are derived from the major question; they are:  What are the worldwide tools and systems used to evaluate the energy efficiency in the envelope retrofit of existing buildings?  What are the modern technologies used globally in achieving net zero energy principles in the existing buildings envelope retrofit?  What are the proposed scenarios for the envelope retrofit of multi-storey residential buildings help in obtaining net-zero-energy buildings?  What are the proposed scenarios of ventilation using the building envelope in Gaza in order to get NZEB?  What are the proposed scenarios of RES generation to get NZEB?

1.2 Aim and Objectives

The study aims to identify the Net Zero energy retrofit strategies that could be applied on the existing building envelope in Gaza, therefore, net site energy savings can be achieved. The following objectives derived from the previous aim. They aim to:  Identify the worldwide tools and systems used to assess the energy efficiency of building envelopes retrofit.  Find out the modern technologies used globally in achieving net zero energy in the envelope retrofit of existing buildings.  Propose scenarios for the rehabilitation of the envelopes of the existing multi- storey residential buildings in Gaza in order to obtain a net-zero-energy building.  Propose scenarios of ventilation using the building envelope as a retrofit process in Gaza in order to get NZEB.  Propose scenarios of RES generation in Gaza in order to get NZEB.

1.3 Signification

This study suggests and develops strategies concerning about building envelope retrofit. It’s believed that, these strategies can encourage decision-makers, architects, and owners of buildings to exploit the envelope of existing buildings to get net zero energy ones. In addition, the green retrofit will help to reduce electricity consumption. Lastly, it will reflect positively the environment, quality of life, and reduce carbon dioxide emissions resulting from means that used in the heating, air conditioning, and lighting.

1.4 Limitations

1. Spatial limitation: This study was applied on Al-Quds Engineers apartment building which is located behind the old Prim-minster Council in Gaza city. 2. Temporal limitation: this study was applied in the academic year of (2016-2017). 3. To answer the research’s questions, five energy measure was only analyzed using DesignBuilder V5 simulation tool. 4. DesignBuilder V5 incorporates with EnergyPlus engine that depends on ASHRAE standard guide.

1.5 Previous studies

Most green retrofit research conducted individually whether for retrofit assessment projects or for the economic feasibility of existing green retrofit one. Although these studies are prepared by qualified architects and practitioners, the insufficient image was given cannot help the decision-makers to decide which building can be selected to apply a set of retrofit alternatives, preventing the spread of green retrofitting (Ayyad & Fekry, 2016). However, it is worth to mention, many of countries have identified special green building systems: a building or a certain house should get formal approval that includes the need to improve the energy situation in the building. By the meaning, improving energy efficiency in buildings is a legal issue that the law of Turkish imposed (Karzem, 2011). As follows, many authors take care of upgrading

the envelope of the buildings in their articles in order to get an efficient energy envelope, then, they get NZEBs. 1. An analytical study provided by Alkhateeb, Hijleh, Rengasamy, and Muhammed (2016) consist of a set of drivers and technical measures that have been employed in the UAE in order to get energy efficiency envelope. It can be achieved by the most common building envelope retrofit measures in the UAE: HVAC optimization, efficient lighting, and performance of free resources of water heating. The result was to decrease the energy consumption by up to 50%. 2. Ascione, De Masi, de Rossi, Ruggiero, and Vanoli (2016) presented the study of optimization of building envelope design for NZEBs in Mediterranean climate: the analysis of residential case study conducted for four cities (Madrid, Nice, Naples, Athens). These cities are characterized by different climatic conditions. The adopted methodological approach combines the use of dynamic energy simulation tool (EnergyPlus) and a constrained multi-objective optimization algorithm. The case study was a single-storey detached building. Some general indications obtained from the results of the case study. In Mediterranean climate, for minimizing heating demand, walls made of autoclaved cellular concrete or with bricks and integrated expanded polystyrene (EPS) or traditional brick wall with hollow blocks and external wooden fiber insulation can be selected. Minimization of cooling demand requires adoption of cool-colored roof, highly insulated. In any case, windows should be triple selective systems and both external and internal shading systems (shade roll) are required. 3. Baran, Dumitrescu, and Pescaru (2016) have studied the possible of existing education buildings in EU to become nZEBs, by practicing current technologies based on enhancing the general level of thermal protection. There are many other measures to save or to gain green energy for the building, like the use of photovoltaic panels installed on terraces or on the opaque portion of the southern façades. Any existing public building transformed into nZEB could be an example of good practice in urban settlements 4. Alaidroos and Krarti (2015) presented a comprehensive analysis study in order to improve the energy performance of residential buildings in the Kingdom of Saudi Arabia (KSA) through optimizing the building envelope elements. The optimization process was based on life-cycle cost and energy savings. In this process, five climate

zones in KSA: Riyadh, Jeddah, Dhahran, Tabuk, and Abha, were evaluated in order to determine the Optimum packages of energy efficiency measures. The base case building was a detached house. EnergyPlus was selected in order to perform the building energy simulation analysis. The building envelope energy conservation measures were: (1) Wall insulation. (2) Roof insulation. (3) Window area. (4) Window glazing. (5) Window shading. (6) Thermal mass. The optimal energy savings were 47.3%, 41.5%, 43.19%, 41.1% and 26% for Riyadh, Jeddah, Dhahran, Tabuk and Abha, respectively. 5.Elgendy and Mekkawi (2015) presented simulation-based studies to reach the net zero energy target for a housing prototype in Alexandria, Egypt. A reduction of 38.2% in the total site energy consumption can be achieved on changing design decisions and parameters; building orientation, location of windows, roof insulation, wall construction materials, glazing types, and shading devices. 6. Serghides, Dimitriou, Katafygiotou, and Michaelidou (2015) studied if it is possible for an old single-family house to reach the NZEB standards and found the lurking impediments and challenges, through building simulations. Various refurbishment scenarios in Cyprus were developed, with the employment of NZE strategies. According to the analysis of the results, the efficiency of each strategy and technique employed towards reducing the energy consumption and the greenhouse gas emissions was assessed, in terms of its cost-effectiveness. It has a share of 24% of the total investment, and incurs a saving of only 2kWh/m2year on the total energy consumption. 7. Loussos, Konstantinou, van den Dobbelsteen, and Bokel (2015) investigated an approach which was implemented in a case study of an existing post-war residential building in Utrecht, Netherlands. The purpose of the paper was to develop a design methodology for existing residential buildings, which lowers the operational as well as the embodied energy as much as feasible. Using this design method has appeared in a design with a very low embodied energy. The façade materials are only 3.9% of the total operational and embodied energy after 35 years. Applying PV-cells on the roof, the embodied energy rises. However, it reduces the operational energy significantly, decreasing the total energy by 90% compared to the current situation. By utilizing PV cells in the ultimate design, the embodied energy is 25.8% of the total

energy, declaring that by making a building with a very low operational energy, the embodied energy becomes a larger part of the total life cycle energy. 8. In Sweden, there is an expanded attention from developers and property owners to build and accomplish buildings with green space on the roof, and even walls. With the growing interest, the demand to build awareness increases regarding the green building envelopes influencing on, among other things, moisture, temperature circumstances in the construction, and energy use for the building (Capener & Sikander, 2015). 9. Otherwise, De Angelis, Pansa, and Serra (2014) displayed a retrofit case study of a social housing quarter in Italy which served by a neighborhood heating system. Sustainable retrofit strategies economically have been considered including evaluating the cost of refurbishment interventions. Both envelope and systems refurbishment works have been examined. The Cost of Conserved Energy method is used to evaluate the whole interventions, also to choose among different refurbishment options. In addition, it is used to assess the pay-back of the investments by the cash-flow method, and analyze different funding systems and incentives. 10. Sang, Pan, and Kumaraswamy (2014) have tested the decisions made for energy- efficient building envelope design in Hong Kong. Reasonable design decisions in housing energy saving can be achieved by taking into account ambient environment, windows and walls types, and the potential measures. Annual cooling demand reduces about up to 46.81%. The measures of reducing the solar heat gain are more effective than those of reducing conduction through external walls. The paper emphasizes the significance of integrating energy simulation into design decision-making in producing more energy-efficient buildings 11. CMHC (2012) illustrated strategies for building envelope insulation and airtightness retrofits that can be implemented as a part of highly energy efficient building envelope energy retrofits in typical Canadian houses. The insulation and airtightness retrofits are technically possible and decrease energy consumption and costs, but can have relatively long payback periods. According to NZEB perceptions, the previous studies can be divided into two groups. One of them handled the subject as a polar to manage the energy consumption in the existing buildings as decision-making tools. While the other ones used multi- objective approaches to get energy efficiency envelopes. These approaches relied on a

package of energy measures that can minimize the energy consumption in the buildings as a first step then generates the energy by RES. Also, it provides an effective way to improve the energy efficiency of the existing buildings. This study provides a guideline for decision makers, architects, and owners to support any initiative efforts for using NZE to improve the thermal behavior of stock buildings. Moreover, it provides many suggestions for the envelopes to get NZEBs. This is by using local and prevailing methods. In the same context, it proposes many strategies for ventilation such as SHDs, DSF, and GDSF. So, this facade retrofit design improves the thermal envelope of the existing building. Lastly, it provides many suggestions for RES generation to accomplish the notion of NZEB as retrofit works.

1.6 Overview of thesis

The study is divided into seven chapters concerning about finding net-zero energy strategies through the building envelope retrofit in Gaza. The chapters have been arranged according to the objectives of the study. These chapters are as following; Chapter 1 is an introduction about the subject of the study. It includes research problem, objectives, signification, limitations of the study, and previous studies. Chapter 2 is divided into six domains. The first domain is a background about net zero energy buildings. The Second domain concerns about the definitions of NZE that reinforces the meaning of this study. The third domain narrates the methodology of NZEB. The fourth domain shows the assessment tools for NZE retrofit. The fifth domain shows the role of building industry in the field of NZE retrofit, especially, what kind of technical feature to achieve. The sixth domain concentrates on the reason for supporting the idea of NZEB in the residential sector globally and locally. Chapter 3 is a methodology of the study including research design, research population, target population, sampling, and research tools. In addition, it involves simulation tools and validation, modelling cases setup, and baseline parameters, Chapter4 shows a building envelope retrofit in order to achieve NZE in Gaza using four proposed energy measures: U-value, shading devices and shading coefficient, airtightness, and green roof. It shows and explains the results that are educed by DesignBuilder V5 in order to obtain NZEB.

Chapter 5 displays the proposed scenarios of ventilation using the building envelope as a NZE retrofit process in Gaza using shading devices, double skin facade, and vertical greenery system. This section concerns about simulation tool results that the researcher conducts to achieve NZEB. As for, natural ventilation was supported by Computational fluid dynamics CFD. Chapter 6 shows the results of generating energy by renewable energy sources using PV panels, in addition to cost effectiveness. Chapter 7 is conclusion and recommendations.

Figure (1.1): The structure of the study

Chapter 2 State of The Art

Chapter 2 State of the art

Introduction

The stock of existing building in Gaza represents civilized appearance for Gaza. Besides, the aesthetic value is not the only thing to realize the appearance of the facade, and so is the energy efficiency. So, there is a need to know the kind of innovation and function that can be used to accomplish the whole sight? There is a global trend toward sustainability and green retrofit. Many articles have discussed the potential of employing the envelope of buildings to achieve NZE buildings. So, this chapter clarifies six main issues related to NZE. First one is a background about a net zero energy retrofit. The second one is the definition of NZEB and terms that they correlated with the meaning of NZEB. The third one is about what is the methodology of NZEB, especially in retrofit process. Fourthly, the reasons for supporting the idea of NZE in the residential buildings sector: globally and locally. Fifthly, NZER assessments, and the sixth domain is envelope technologies.

2.1 Background about a net zero energy retrofit

Recently, keeping an eye on global warming, the consumption of fossil fuel resources and the environment pollution has led to the increase of the attention toward the energy efficiency of building stocks (Ballarini, Pichierri, & Corrado, 2015). The existing building stock that was built in the post-World War II period has strong structural systems but inefficient envelopes. Especially in the US, the main factor that played the big role in causing the displacement of passive adaptations, as well as the natural ventilation and daylight, is the cheap energy that used in mechanical air conditioning systems (Martinez, Patterson, Carlson, & Noble, 2015). This practice of producing the carbon dioxide emissions can deeply affect energy saving goals when energy-efficiency design strategies are considered (Aksamija, 2015). As a result, applying the sustainability concepts is a necessity in the designing and construction of buildings (Valdiserri, Biserni, Tosi, & Garai, 2015). Xu, Chan, Visscher, Zhang, and

Wu (2015) clarified that “Building Energy Efficiency Retrofit is considered as a valuable way to improve the energy efficiency of high-energy-consumption buildings.”. To achieve energy efficiency in the building field, the idea of Net Zero Energy Building (NZEB) has been broadly applied as an approach encouraging renewable energy integration on-site (Aksamija, 2015). Even if there are many definitions of zero, near zero, or zero net energy buildings, but it is essential to mention that the real meaning is energy efficiency and conservation. Torcellini and Pless stated that “across all definitions and classifications, one design rule remains constant: reduce energy demand to the lowest possible level first, then address energy supply.” (as cited in Patterson, Vaglio, & Noble, 2014). Four well-documented definitions are reported by Torcellini, Pless, Deru, and Crawley (2006): net-zero site energy, net-zero source energy, net-zero energy costs, and net-zero energy emissions. In addition, these definitions are applied to a set of low-energy buildings for which broad energy information are accessible. Usually, the objectives of net-zero energy can be recognized through enhancing building envelopes, applying passive design strategies, installing high performance HVAC systems to reduce heating and cooling loads, decreasing lighting and other electric loads, therefore, making it possible to substitute the required energy balance with renewable means, for example, solar photovoltaic or wind turbines. So, succeeding net-zero energy aim is a challenging objective, particularly with regards to retrofit projects, since more restrictions are usually imposed on existing buildings than new one (Aksamija, 2015). Thus, the façade is an important system for emphasizing a high-performance building (Martinez, Patterson, Carlson, & Noble, 2015).

2.1.1 The historical development of the idea of a residential NZEB Kapsalaki (2013) displayed the historical development of the idea of a residential NZEBs, also Table (2.1) displays their main technical features:  NZEBs is an extension idea from the concept of “solar” or “passive” buildings, which had been developed since the 1970’s.  As shown in Figure (2.1a), in 1992-1995, the Self-Sufficient Solar House in Freiburg was developed by the Fraunhofer Institute. The sun was the only supply energy. The home was not connected to the grid whenever there was no other

external supply of non-solar energy depending on solar-generated hydrogen as the energy storage form for electricity & heat and a fuel cell as a miniature cogeneration power plant.  As shown in Figure (2.1b), in 1998, a “PVRES’ experimental residential building, Lakeland, Florida, was super energy efficient photovoltaic residence. The ‘PVRES’ had many energy efficiencies features such as a high level of thermal insulation, a white reflective roof system, a solar water heating, an efficient interior appliances and lighting, a high-efficiency heat pump and a photovoltaic (PV) system. Although finding features, the house did not achieve zero annual balance. About 75% of final energy were covered.

a. The Self-Sufficient Solar House b. “PVRES’ residential building

Figure (2.1): 19th examples of NZEB

Source: Kapsalaki (2013)  As shown in Figure (2.2a), in 2005, solar harvest, Boulder, Colorado, U.S, was built by Eric Doub and his company Ecofutures Building Inc. hybrid solar design features. Heavy thermal insulation, high-performance glazing and windows and highly efficient equipment. All the energy needs for appliances were covered from PV panels, while space heating and domestic hot water are provided by solar thermal flat-plate collectors.  As shown in Figure (2.2b), in 2005, a zero-energy house (ZEH), two houses were built side by side at the same area of (150m2). Many energy measures are implemented like high thermal mass walls.  As shown in Figure (2.3), in 2006, Tanno meets Gemini, the Plus Energy housing, was built in Weiz, Steiermark, Austria. The first energy positive project includes 22 flats within an area of 3294 m2. The project has many features such as high-

level insulation and triple low-E windows, a high-efficiency heat pump to cover the heating needs of the residences, while the energy consumption is being offset through installed PV panels.

b. solar harvest house b. a zero-energy house (ZEH),

Figure (2.2): 2005th examples of NZEB

Source: Kapsalaki (2013)

Figure (2.3): The Plus Energy housing

Source: Kapsalaki (2013)  In 2006, Solar Plus Haus, located in Flieden, Hessen, Germany.  As shown in Figure (2.4a), in 2007, the ‘Eco Terra, located, in Eastman, Quebec, Canada.

a. The ‘Eco Terra b. Crossway Eco-House

Figure (2.4): 2007-2009th examples of NZEB

Source: Kapsalaki (2013)

 In 2008, Doub presented a retrofit towards NZEB target of a 1970s ranch home in South Boulder, Colorado  As shown in Figure (2.4b), in 2009, ‘Crossway Eco-House’, located in Staplehurst, Kent, UK.

Table (2.1): Main technical features of residential examples of NZEB

Resid- Main Technical Features ential Energy Heating/cooling & Lighting & Electricity case Envelope Air change management hot water Appliances Production studies Systems  Air tight  Wall U-value 0.57W/ m2.K. construction  CFL 2  Roof U-value 0.19W/ m .K (average lighting Data logger for  White reflective roof ACH=0.13)  Solar water heating Photovoltaic weather, thermal PVRES crystalline conditions and  Thermal break + argon filled  No  Efficient modules major end-use windows mechanical  High efficiency appliances electric loads  Overhangs around the ventilation HVAC system building  Air tight  Solar thermal construction heating (12 roof-  Wall U-value 0.17W/ m2.K (average mounted solar  CFL Data monitoring  Ceiling U-value 0.126W/ ACH=0.1) thermal collectors) lighting with m2.K  Heat  Summer cooling by 8.74 kW roof Solar temperature,  Double glazed fiberglass recovery natural chimney mounted PV Harvest  Efficient energy and windows (HR) effect through array appliances comfort system ventilation skylight  Shading provided by solar sensors panels and trees. system  Ground cooled air  Natural through buried pipes Ventilation  High efficiency AC  Thermal mass walls  CFL  Radiant barrier sheeting  AC system with Data monitoring evaporative lighting to measure  Blown in attic insulation Photovoltaic ZEH condenser 2.3 m2 weather (U=0.15W/m2.K) - system of Nevada solar collector  Efficient conditions and  Low-e windows 4.8KWp  Tank less gas hot appliances electricity and  Large overhangs 2.43m water heater gas consumption

 CFL  Wall U-value 0.11W/ m2.K High efficiency heat Roof Tanno lighting  Roof U-value 0.09W/ m2.K Mechanical pump for space integrated meets  Efficient -  Triple glazed low-e windows ventilation heating and domestic photovoltaic Gemin appliances hot water purposes system

2  CFL  PV panels Solar  Wall U-value 0.11W/ m .K) Mechanical lighting  Wind Plus  Triple windows ventilation Solar collectors -  Efficient turbine House with HR appliances

 Air tight  CFL 3KW Data monitoring  Wall U-value 0.16 W/ m2.K construction lighting building with sensors for  Roof U-value 0.125W/ m2.K integrated thermal Eco-  Mechanical Geothermal Heat  Triple glazed low-e coated photovoltaic performance and Terra ventilation Pump (GHP)  Efficient argon filled windows thermal energy appliances system efficiency (BIPV/T) assessment

 26m2 of  Wall U-value 0.12W/ m2.K  No conventional Built in sensors photovoltaic  Roof (U=0.12W/ m2.K) heating  CFL, measure thermal  Extracted heat is LED & thermal performance, Crossway  Triple glazed argon filled Mechanical stored in phase halogen (PV/T) electricity, water Eco windows ventilation change materials lighting system consumption House  Vault overhangs & integrated with HR (PCMs) creating  Efficient  Biomass and solar blinds within some windows heat battery for hot appliances boiler thermal water & top up heat monitoring

Source: Kapsalaki (2013)

 In 2010, Attia presented the results of a study regarding a possible retrofit to NZEB level of a chalet in Ain- Sukhna, Egypt. - He investigated several passive and active design strategies and concluded that on economic level the most active design strategies (i.e., those dealing with equipment) and even the thermal upgrade of the envelope were not advantageous due to the long-term payback period.

2.1.2 NZE façade retrofit simulation tools “The building design is an iterative process from the conceptual design up to the final process, so the use of computer-based tools here is vital” (Lapinskiene & Martinaitis, 2013). Building energy simulation is important for the study of energy efficiency in buildings. Computer simulation programs are effective analytical tools for building energy research and evaluation of architectural design (as cited in Samaan, Farag, & Khalil, 2016). The popular simulation tools used in a subject of NZE are EnergyPlus and DesignBuilder. EnergyPlus is a whole building energy simulation program for modeling building heating, cooling, lighting, ventilating, and other energy flows. DesignBuilder is a simulation program for checking building energy, carbon, lighting and comfort performance. Also, it Links to all major 3-D CAD software. It Includes parametric analysis (Lapinskiene & Martinaitis, 2013). Samaan et al. (2016) used the simulation tools to investigate the important role of these tools to energy efficiency in term of architecture practices. Many authors have managed to use these tools to analyze multi-objective for energy optimization. Samaan et al. (2016) presented an empirical study to optimize the cooling loads and daylighting levels in halls of Egyptian Universities, using DesignBuilder software, with EnergyPlus and Radiance engines. While Sang et al. (2014) examined the potential of using representative building envelope design measures to reduce energy demands in Hong Kong. The study conducted by using eQUEST simulation tool. Fan and Xia (2015) investigated a framework for building envelope retrofit of existing buildings. Multi-objectives energy optimization problem has been formulated and solved by using MATLAB. Steskens, Vanhellemont, Roels, and Van Den Bossche (2015) explored an efficient method for the retrofit of a house which has been implemented by a user-friendly computer Program as a decision-

making tool for the energy efficient refurbishment of residential buildings. (Al- Auqeily & Al-Yousif, 2008) claimed that reduce cooling load can be investigated by intelligent envelope system conducted by using Ecotect program. The government in Cyprus certificates use iSBEM-Cy modeling tool for the energy performance calculation. Also, it uses the categorization of energy efficiency in buildings and the calculation of CO2 emissions according to the European Directive 2002/91/EC (as cited in Serghides et al., 2015). However, Attia (2011) provided a compressive study about tools used in energy evaluations in the context of NZE. This can help architects during early design phases. The study depended on five criteria including usability, optimization, interoperability, accuracy and design process integration of the tools.

NZEB Criteria

Vasari

BeOpt

HEED

eQUEST

ECOTECT Energy 10

Openstudio

IESVE-Ware

DesignBuilder

Solar Shoebox Metrics Energy Environmental (CO2) Economic Embodied Energy Urban Scale NZEBs Comfort & Climate Climate Analysis Static Adaptive Comfort Visualisation Passive Solar Geometry, Massing Daylighting Natural Ventilation WWR Thermal Mass Shading Devices Energy Efficiency Envelope Insulation Glazing Performance Envelope Air Tightness Artificial lighting Plug Loads Infiltration rate Mechanical Ventilation Cooling System Heating system Renewable ES Photovoltaic (PV) Building Integrated PV Solar Therm. Collectors Innovative Solution & Technologies Mixed Mode Ventilation Advanced Fenestration Green Roofs Cool Roofs Double Skin Façade Solar Tubes Phase change materials Figure (2.5): Results of the NZEB Tools Mechanics

As shown in Figure (2.5), the results adopted a NZEB tools matrix that depended on six criteria: metric, comfort & climate, passive strategies, energy efficiency, renewable energy systems (RES) and innovative solutions and technologies. The matrix described tools limitations and major requirements to meet the NZEBs objective implications. Currently, some of these tools are developed and they are able to simulate extra functions. For example, DesignBuilder is able to simulate models with PV, green roof, and double skin facade.

2.2 Net-zero energy building (NZEB) definition

This category displays what the net zero energy building does mean. In spite of the general recognition of the concept of the net-zero energy building, the definition is still lacking. It is perceived that the diversity of definitions are possible in the order to be reliable with the purposes and political targets that lay behind the promotion of Net ZEBs (Sartori et al., 2010; Sartori, Napolitano, & Voss, 2012). According to the national renewable energy laboratory (NERL), net-zero energy building (NZEB) is a building that greatly reduces energy needs. An energy efficiency can be achieved regarding the balance of energy needs and energy supplied by renewable energy technologies (Pless & Torcellini, 2010). The National Institute of Building Sciences (2015) has defined the net-zero energy building as an energy efficient building whose the annual delivered energy is less than or equal to the on-site renewable exported energy. Also, it annually produces energy as well as it consumes. It is a building connected to the grid using an amount of energy, as it will need then it supplies energy back to the grid as it is produced. Taking into account the required energy will be generated by renewable energy means such as solar photovoltaics. Moreover, the net- zero building is a high-performance envelope building that can be achieved by reducing the heating, cooling and other electrical loads as possible as highly energy- efficient mechanical and electrical systems. It is essential to mention that net-zero energy principles would be more difficult to achieve without a high-performance building envelope CMHC (2012). So, we can deduce that net-zero building depends on three main principles as following: the building should have a very high-energy performance envelope, energy

demands should be reduced to nearly zero and energy requirements should be generated by on-site renewable resources (Albadry, 2016; Hermelink et al., 2013). However, net-zero energy buildings are the buildings shared in producing energy and offset the remaining energy demands by using renewable energy. But, the essential difference between them is how and where the renewable energy is generated. The National Renewable Energy Laboratory (NREL) has widely adopted four definitions of net zero energy. They are net zero site energy, net-zero source energy, net-zero energy costs, and net zero energy emissions. The trade-offs between these definitions are regarding cost and pursuing metrics, and which type of renewable energy can be used to meet each definition. Even though, there is the potential to use these definitions in combination if a project team desires. For example, a building could be both net-zero site energy and net zero emissions (Carmichael & Managan, 2013). These definitions are clearly explained as following:  Net Zero Site Energy: A site ZEB produces at least as much renewable energy as it uses in a year when accounted for at the site.  Net Zero Source Energy: A source ZEB produces at least as much renewable energy as it uses in a year when accounted for at the source. Source energy refers to the primary energy used to generate and deliver the energy to the site.  Net Zero Energy Costs: In a cost ZEB, the amount of money the utility pays the building owner for the energy the building exports to the grid is at least equal to the amount the owner pays the utility for the energy services and energy used over the year.  Net Zero Energy Emissions: A net-zero emissions building produces at least as much emissions-free renewable energy as it uses from emissions-producing energy sources.

In case of this study, the only definition that is used is net zero site energy. To complete the image of the concept of NZEB, we need to realize that they are many aspects should be taken into account: metric, comfort level and climate, passive strategies, energy efficiency, renewable energy systems, and innovative solutions and technologies.

2.2.1 Fundamental aspects of NZEBs Sartori et al. (2012) have concluded six fundamental aspects of net-zero energy buildings as following in Table (2.2). Table (2.2): Fundamental aspects of NZEBs

1. Metric: There are several definitions for NZEBs that are based on energy, environmental or economic balance. Therefore, a NZEB simulation tool must allow the variation of the balance metric. 2. Comfort Level and The net zero energy definition is very sensitive toward climate. Consequentially, Climate: designing NZEBs depends on the thermal comfort level. Different comfort models, e.g. static model and the adaptive model, can influence the ‘net zero’ objective. 3.Passive Strategies: Passive strategies are very fundamental in the design of NZEB including daylighting, natural ventilation, thermal mass and shading. 4.Energy Efficiency: By definition, a NZEB must be a very efficient building. This implies complying with energy efficiency codes and standards and considering the building envelope performance, low infiltration rates, and reduce artificial lighting and plug loads. 5.Renewable Energy RES are an integral part of NZEB that needs to be addressed early on in relation to Systems (RES): building from addressing the panels’ area, mounting position, row spacing and inclination. 6. Innovative Solutions The aggressive nature of ‘net zero’ objective requires always implementing and Technologies: innovative and new solutions and technologies. Source: (Sartori et al., 2012)

2.2.2 Terminology of net-zero energy Depending on the aforementioned definition of NZEB, many terms will be explained in this item: energy, high-performance, energy efficiency and energy savings.

i. Energy Energy is the capacity for doing work. Customary measurement units are British thermal units (Btu), Joules (J) or kilowatt-hours (kWh) (The National Institute of Building Sciences, 2015).

ii. High energy performance building A high-energy performance building is a building consuming a little amount of energy as possible in annual basis for heating, cooling, ventilation, light, and hot water. This is compatible with people needs and domestic appliances. Having a climate- optimized insulation and using thermal mass are strongly expected to integrate into its skin in order to balance thermal energy flows, in addition to highly efficient and innovative technologies that regulate the use of the available delivered energy resources or available energy in the environment of the building (EC- Joint Research Centre, 2013).

iii. Energy efficiency Energy efficiency is a managed energy usage provides tasks with less energy depletion without affecting the people's thermal comfort by implementing appropriate measures and techniques to new or existing buildings. Minimizing the energy consumption, reduction of CO2 emission, the cost-effectiveness, and the indoor air quality are the main factors needed to be considered at all the times (Alkhateeb et al., 2016).

iv. Energy savings in buildings According to EU Energy Efficiency Directive (2012/27/EU) guideline Article 2.5, energy savings is defined as “an amount of saved energy determined by measuring and estimating consumption before and after implementation of energy efficiency improvement measures, whilst ensuring normalization for external conditions that affect energy consumption” (The Coalition for Energy Savings, 2013). In order to understand the NZEB basics, many terms should be explained complementing with Figure (2.6). Starting with generating the energy via renewable energy sources and their classifications, then building system boundary, annual energy loads, delivered energy and exported energy, weighted system, and energy grid.

Figure (2.6): NZEB relevant terminology

Source: (Sartori et al., 2012)

2.2.3 Generating energy via RES and their classification The common use of using RES in Gaza is to install PV models on the roof in order to generate a certain amount of energy without giving up using the grid. But, nowadays there are many options for energy supplying by using RES, as shown in Figure (2.7). So, the question here is what the RES does mean, and what are the possible options to generate them? RES is the energy resources that are naturally replenishing but flow- limited. They are virtually inexhaustible in duration but limited in the amount of energy that is available per unit of time. Renewable energy resources include biomass, hydro, geothermal, solar, wind, ocean thermal, wave action and tidal action. Also, The RES generating energy might be depending on many ways to supply: Low-energy buildings, footprint, on-site, off-site, and green infrastructure. These ways can be classified into five options that are explained in Figure (2.7), and Table (2.3). Taking into the consideration that efficiency measures devices such as daylighting are not considered on-site in the NZEB context. They cannot be commoditized, exported, and sold, but it is considered to be demand-side renewable technologies. Combined heat and power systems that use fossil fuels to generate heat and electricity are considered to be demand-side technologies.

Figure (2.7): Renewable energy supply options

Source: (Pless & Torcellini, 2010)

Table (2.3): The classification of NZEB

Source: (Marszal et al., 2010)

2.2.4 NZE building system boundary NZE criteria could be applied to one building or a set of buildings as well as the neighborhood. This requires defining the area that NZE should serve exactly which it called system boundary. The boundary means in which the energy flows in or out the system and it includes physical and balance boundary, as shown in Figure (2.8). Physical boundary: can encompass a single building or a group of buildings; determines whether renewable resources are ‘on-site’ or ‘off-site’. Balance boundary: determines which energy uses (e.g. heating, cooling, ventilation, hot water, lighting, and appliances) are included in the balance.

Figure (2.8): The system boundary of NZEB

Source: (The National Institute of Building Sciences, 2015)

2.2.5 Annual energy loads Energy usage during at least the period of 12 consecutive months.

2.2.6 Delivered energy Any kind of energy it could be whether bought or sold for the energy usage of the building. For example, the energy which involves electricity, steam, hot water or chilled water, natural gas, biogas, landfill gas, coal, coke, propane, petroleum and its derivatives, residual fuel oil, alcohol-based fuels, wood, biomass and any other material consumed as fuel (The National Institute of Building Sciences, 2015). Moreover, it is a type of energy that flows from the grids to the buildings, specified per each energy carrier in (kWh/y) or (kWh/m2y), which is imported by the building. (Sartori et al., 2012).

2.2.7 Exported Energy On-site renewable energy supplied through the site boundary and used outside the site boundary (The National Institute of Building Sciences, 2015). It flows from buildings to the grids, specified per each energy carrier in (kWh/y) (Sartori et al., 2012).

2.2.8 Weighting system It is knowledgeable for NZE that the process is an exchange benefit with energy in or out the building. So, there is an amount of energy that is supplied and another is delivered. Here, the need for weighting system is required. A weighting system converts the physical units into other metrics, for example, accounting for the energy used (or emissions released) to extract, generate, and deliver the energy. Weighting factors may also reflect political preferences rather than purely scientific or engineering considerations. - Weighted demand: The sum of all delivered energy (or load), obtained summing all energy carriers each multiplied by its respective weighting factor. - Weighted supply: The sum of all exported energy (or generation), obtained summing all energy carriers each multiplied by its respective weighting factor.

Weighting system helps the formal authorities to measure the amount of the energy that it should be received from the building to the grid. Then, the role of investment is taken place to encourage people to support the idea of sustainability. Here the deciding incentive is possible as a mortgage. Consequently, weighting system achieves the NZE balance. Net zero energy balance is a condition that the weighted supply meets or exceeds the weighted demand over a period almost annually. Two options of NZE balance can be determined either between delivered and exported energy called import/export balance or between load and generation called load/generation balance. While a third option is possible called monthly net balance, using monthly net values of load and generation.

2.2.9 Energy Grids Energy grid is the supply system of energy carriers such as electricity, natural gas, thermal networks for district heating/cooling, biomass, and other fuels. A grid may be a two-way grid, delivering energy to a building and occasionally receiving energy back from it. This is normally the case for electricity grid and thermal networks. Most of the authors focusing either on off-grid ZEBs or on on-grid ZEB approaches in their related publications. The main difference between them is that the off-grid ZEB is a building that it does not connect to the energy infrastructure. This means it does not buy energy from any external sources and its energy balance calculations only occur

within the building. Also, this approach commonly called “autonomous” or “self- sufficient” building. While the on-grid ZEB is called “net zero” or “grid-connected”. It is a building connected to one or more energy infrastructures such as electricity grid, district heating and cooling system, gas pipe network, biomass, and biofuels distribution networks. This means the building has the ability to both buy and sell energy from/to the utility grid (Marszal & Heiselberg, 2011).

2.3 Net zero energy retrofit of envelope methodology

Aforementioned examples of NZEB made the researcher of this study look for how to apply reasonable NZE criteria to the built buildings in a simplified systematic way, the process is called NZE retrofit. The answer was in Figure (2.9) as well as existing buildings, the starting point represents the performance of a building that built according to the slightest requirements of the building code or the performance of an existing building before retrofit actions. Generally, the way to achieve a Net ZEB consists of two steps: (1) reduce energy demand (x-axis) by means of energy efficiency measures; (2) generate electricity as well as thermal energy carriers by means of energy supply options to get enough credits (y-axis) to achieve the balance (Sartori et al., 2010; Sartori et al., 2012; The National Institute of Building Sciences, 2015).

Figure (2.9): Displays a graph of energy balance for NZEB

Source: (Jordan, Hafner, Kuhn, Legat, & Zbašnik-Senegačnik, 2015; Sartori et al., 2010)

If the structure of the building is hard to modify, almost, the process of NZE retrofit will start with the envelope of existing building,

2.3.1 Net zero energy façade retrofit The building envelope performs many different functions, offering security, fire protection, privacy, comfort and shelter from the weather in addition to aesthetics, ventilation, and views to the outdoors benefits. In fact, the issue of reducing the energy consumption in the building is incorporated with the needs of the occupants which represent the key challenge of optimizing the building envelope (IEA, 2013a). A building envelope retrofit plan should be included as a set of retrofit actions especially when the main purpose of the retrofit process is to reduce the energy consumption in the building. The imperative need to improve the thermal properties of the building envelope is the most logical solution (Basarir, Diri, & Diri, 2012). In the same context, for example, Fan and Xia (2015) have presented the retrofit approach that consisted of four components: windows, external wall insulation materials, roof insulation materials and solar panels. Meanwhile, the choice of the retrofitting strategies undoubtedly depends on the improvement of building envelope energy performance. Taking into account the different aspects as the building envelope components and their technologies, architects and engineers must have the understanding of them to achieve good results in this area (Basarir et al., 2012). In contrast, conventional retrofits are smaller in scale and cost whenever the process depends on replacing one or a few technologies in a building to achieve a modest reduction in energy consumption or greenhouse gas emissions (≈ 15–25%) (Rysanek & Choudhary, 2013). IEA (2013a) formatted a roadmap for energy efficient building envelopes whose major goal is to show how policymakers and the building industry can promote and adopt advanced practices that result in the widespread construction of low-energy or zero- energy buildings. Three stages of technological evolution to get efficient building envelopes as shown in Figure (2.10):  The first stage is a poor performance of building envelope, single-glazed clear windows, and no insulation and high rates of air leakage.

 The second would be a typical code-compliant building being constructed today in the world, which has double-glazed, low-E windows and high levels of insulation, and is sealed fairly well.  The third stage is represented by buildings of the future with greater passive design, highly insulated windows, and passive heating contributions, along with advanced facades that harvest natural daylight while reducing cooling loads. Such buildings will probably incorporate solar thermal systems.

Figure (2.10): Transforming construction to low energy building

(IEA, 2013a) In the case of NZE, as an eventual adaptability design, the sustainable design and construction of buildings have the capability to adopt emergent technology that brings the building close to NZE with respect the priority to both performance and appearance. But, nowadays, the building stock was not considering the future adaptability. Thus, existing façade systems roughly do not easily modify or retrofit (Patterson et al., 2014).

2.3.2 Measures of energy efficiency building envelopes Defining the energy measures that should be applied to the certain building is the first step toward obtaining NZEB. It is a deciding stage of what kind of energy measures that should be implemented to get energy efficiency envelope also it reduces the energy consumption in the building. For instance, in different climatic zones, several envelope design measures are required. Any approach to energy-efficient building envelope design depends on how much this building has responded to the surrounding ambient, i.e. it takes advantage of the local climatic conditions. In hot-

humid climate, for example, the high-performance envelope measures encompass catching natural daylight in order to reduce artificial lighting, simultaneously; it prevents unwanted solar heat gain. Also, they involve improving thermal resistance and enhancing natural ventilation (Attia, 2012). Besides, Evangelisti et al. (2015) explained that “Wall performance depends on its thermal resistance, which is a measure of how well an envelope resists the heat-flow, and on the material heat capacity, which describes its thermal storage capability. Higher thermal resistance values allow us to obtain a better insulation and depend on thermal conductivity and thickness of each layer”. Finally, the building refurbishment is totally preferred when the energy savings are achieved largely and having less effect on the environment. The reason is that when renovating the whole building, all the parts of the building are considered and it is easier to solve the junctions of the façade elements without degrading the architectural appearance of the building (Arumägi, Mändel, & Kalamees, 2015). For that, “The European Directive 2012/27/EU establishes a set of energy measures to help the EU to reach 20% energy efficiency target by 2020. Under this Directive, all the EU countries are required to use energy more efficiently at all stages of the energy chain, from its production to its final consumption”. As cited in (Ballarini, Pichierri, & Corrado, 2015). In particular, the measures could apply to the building envelope according to the retrofit strategies systems. These measures could be passive or active measures that depend on electrical and mechanical systems or measures that could be related to the lifestyle of the occupant which called (behavioral measures), as cited in (Alkhateeb et al., 2016). Moreover, energy efficiency measures including the harvesting daylight need to be compatible with heat rejection measures such as solar and thermal control providing proper shading, advanced glazing, insulation, etc. in order to improve indoor environment quality (Sang et al., 2014). To tradeoff between measures in order to choose one measure over another relies on many factors such as feasibility, applicability, and outcome for each measure. For example, because of its feasibility, passive measures could be chosen to enhance the building envelope (Alkhateeb et al., 2016).

2.3.3 Energy efficiency measures evaluation Regarding façade retrofit, many criteria should be taken into account including the energy efficiency envelope measures. As what was mentioned before in the previous category, the first step is to compile and organize them systematically according to what type of envelope components that they are attached. For example, whenever the heat loss occurred, the efficient retrofit envelope should response to the design and the function of the occupied spaces. On the other hands, building envelope service should not be ignored since it is an integral part such as solar panel system (Konstantinou, 2014). The second step is to assess the ability of these measures contributing to the energy efficiency upgrade. They should be found wherever the reduction in the energy demand is addressed in comparison to the prior retrofit process. Meanwhile, computation dynamic simulation aims to support any future retrofit process since it can assess the building energy performance for each option individually. At the same time, it can simulate every option separately and change at least one component in the model in order to follow the possibility of optimizing the building envelope performance (Konstantinou, 2015). In case of NZE retrofit, a benchmark building was modeling by dynamic simulation tools and coupling with the retrofit envelope action to enable designer rapidly to get flexibly assess the thermal comfort and energy performance of early design alternatives. Also, the generated results valid and support the decision-making tool (Attia, Gratia, De Herde, & Hensen, 2012). After displaying the methodology of NZEB, the curious question here what is the difference between NZEB and green building? Zero energy building is considered a branch of green buildings. Green buildings is a sustainable use of resources in order to reduce a negative impact of buildings on the environment. Zero energy buildings significantly reduce energy use and greenhouse gas emissions for the life of the building. However, zero energy building in some areas may not be considered a green building such as reducing waste, using recycled building materials, etc. Moreover, ZEBs ecologically have a lower impact throughout the life of the building in comparison with green buildings, which they require imported energy to be habitable and meet the needs of occupants (Wikipedia, 2016b). So, what the benefits from energy renovation of buildings? The next category will display some of them.

2.3.4 The benefits from energy renovation of buildings In spite of initial costs associated with the process of the energy retrofit, there are many advantages that can the owner and occupants benefit from (Petersen, 2014).  Energy retrofit can reduce the future energy bills.  Energy retrofit may increase the resale value of the building. This can impact on the financial position of building owners that consequently can affect the society.  A better indoor climate and greater comfort which can improve the wellbeing of users.  Energy retrofit can raise the architectural value of the building which can affect the surrounding environment.  Having an experience in the reducing energy consumption in buildings.  The potentiality of investments in the field of RES generation.  Encouraging local companies to produce envelope components and systems for zero energy-efficient buildings.

As any refurbishment process, there are many factors affect the procedure of net zero energy retrofit of building envelope implementation. Ayyad and Fekry (2016) have pointed to some of them: Building performance with its main components, building age/lifetime, energy consumption rate, building market value, occupancy, retrofitting cost, and built-up area.

2.4 Net zero energy retrofit assessment of building envelope

This section is the answer to question no. one: What are the worldwide tools and systems used to evaluate the energy efficiency in the envelope retrofit of existing buildings? Facade retrofit can range from small repairs (weathering) to a total replacement of the original facade for a new system (Martinez & Carlson, 2014). The performance assessment of the existing façade should be done based on visual inspections, analysis of historical documents (plan, sections, specifications), thermographic inspection, destructive analysis, and static and dynamic hydrothermal simulations (Staljanssens, Mangé, Van Den Bossche, & Moens, 2015). The Energy Performance of Buildings Directive (EPBD) recast (2010/31/EU) answers this

question, by prescribing the cost-optimal analysis in order to detect the best packages of energy efficiency measures (EEMs) to apply to new or existing buildings (Mauro, 2015). This is defined as the energy performance level which leads to the lowest cost during the estimated economic lifecycle (Becchio et al., 2015). The cost-optimality is an innovative and powerful concept that ensures the best trade-off between the two distinct perspectives involved in the building world: the collective (state) one, interested in the reduction of energy consumption and polluting emissions, and the private (single building) one, interested in the reduction of economic disbursement (Mauro, 2015). In addition to the energy analysis and assessment of cost-effectiveness, the evaluation of EEMs considered other building science performance issues, particular, hydrothermal performance. It is critical that the implementation of EEMs does not compromise the durability of the building envelope (CMHC, 2012). Becchio et al. (2015) have applied the methodology framework for calculating cost-optimal levels that is presented by the Directive 2010/31/EU. The methodology involves to:

• Define a reference building (RB) representative of the examined building stock; • Define the energy efficiency measures (EEMs) involving the improvement of the building envelope thermal performances and the efficiency of the systems; • Combine EEMs into packages in order to create different scenarios; • Evaluate the final and primary energy consumptions for the different scenario; • Calculate the costs of each scenario related to the proper economic lifecycle. It is worth to mention that the aforementioned points are related to net zero energy buildings methodology. There are five methods to assess the energy in the buildings. 1) a common method, 2) Deterministic method, 3) Stochastic method, 4) Financial evaluations method, 5) Integrating human value assessment method.

2.4.1 Common evaluation methods for facade retrofits Some studies globally progress a holistic understanding of façade retrofit including the challenges and opportunities. While the others specifically illustrate an aspect related to the subject. For example, Fan and Xia (2015) used a static analysis method to assess the performance deterioration of materials with time, and economic issues, such as life-cycle cost, net present value (NPV) and payback period that benefit decision makers and architects to practice the sustainability in their projects. The

recent study of energy performance concentrates on using a life cycle approach for evaluating facade retrofit. LCA and NPV are considered popular ways used to evaluate and assess the energy retrofit of the building. Martinez et al. (2015) suggested to include a life cycle assessment (LCA) in the planning stage. On the other hands, many researchers take care of pay pack methods. For example, De Angelis et al. (2014) have assessed the cost-optimal energy level on a case study of apartments block building sited in Brescia in northern Italy. Generally, the research investigated the economic sustainability of several energy retrofit strategies for an apartment block building by means of the Cost of Conserved Energy (CCE) method and the pay-back of the investments by using the cash-flow method. Furthermore, there are studies centered on embodied or operational energy. For instance, Loussos et al. (2015) evaluated different façade materials in terms of embodied energy. The high initial investment is always a great barrier to the ZEB development. The optimal integration of different energy-saving and generation technologies that meet building energy demand with minimum cost is the primary principle for achieving a ZEB target. Designers must apply holistic design principles to ensure a cost-effective, environmentally friendly and energy balanced ZEB while providing a comfortable living environment. It is a multi-faceted issue addressing both energy and cost efficient. (Cao, Dai, & Liu, 2016; Martinez & Carlson, 2014).

2.4.2 Deterministic methods for evaluation of facade retrofits To assess any prediction of the building performance based on spatial-temporal variables, many advanced deterministic methods use dynamic simulation models i.e. genetic algorithms method (GAs). Building analysis could take into account load calculations, renewable energy, indoor air quality, ventilation, code compliance and more (Aksamija, 2015; Barthelmes, Becchio, Bottero, & Corgnati, 2014). Regarding the energy analysis, the engineering calculations depending on physics are commonly used to predict the future behavior. Whereas, the outcome of the deterministic methods is obtained in a simulation model directly by their primary input. This method describes the energy flow through the envelope statically (no time variation) (Martinez & Carlson, 2014). Under standard design conditions, the steady-state calculations are accomplished for certain areas by defined thermal zones. For example, the relationship

between adaptive building envelope systems and building occupants. The simulation tool should be able to evaluate both the adaptive building element affects occupant comfort conditions and the specific adaptive building envelope technology that would be under control by individual occupants (Loonen, Favoino, Hensen, & Overend, 2016). Also, Mauro (2015) has investigated the multi-objective improvement of assessment the energy demands by CASA approaches, as shown in Figure (2.11), CASA (Cost-optimal analysis by multi-objective optimization and artificial neural networks (CAMO+SLABE+ANN)) is a combination stage approach that can be applied to each building category for the evaluation of the cost-optimal package of energy retrofit measures (ERMs) with a low computational burden (Mauro, 2015).

Figure (2.11): Examples of multi-objective improvement & assessment of energy demands

Source: (Mauro, 2015) As part of the use of simulation, facade retrofits have been explored using calibrated energy models to examine the behavior of the building under study. This calibration is addressed by some standards such as ASHRAE Guideline 14, International Performance Measurement and Verification Protocol (IPMVP), or the Federal Energy Management Program (FEMP) (Martinez & Carlson, 2014).

2.4.3 Stochastic methods for evaluation of facade retrofits As an alternative to deterministic methods, some studies have evaluated energy retrofit decisions consolidating stochastic models. Random element selections describe the behavior of building performance. As is typical of stochastic models, multiple simulations using uncertain inputs and processes defined by proper

probability distributions develop a range of probable outcomes (Martinez & Carlson, 2014).

2.4.4 Financial evaluations of facade retrofits To consider the facade as part of an energy retrofit, studies need to be framed on a period adequate for financial evaluation longer than the typically 3-5 years payback owners expect for retrofits that only upgrade internal systems. Many complexities appear with systems in the building that have different life spans. Studies have estimated those lifespans: the structure could last the whole life of a building, while equipment would be updated every 8-15 years. Some facade components need to be replaced every 20 years to maintain a longer overall lifespan of the facade system (Martinez & Carlson, 2014). Some of the technologies needed to transform the buildings sector are already commercially available and cost-effective, with payback periods of less than five years. Others are more costly and will require government intervention if they are to achieve wide market uptake (IEA, 2013b).

2.4.5 Integrating human value assessment This assessment method correlated with human factors. The concept of sustainability associated human comfort has exposed many terms. Terms such as the Sick Building Syndrome (SBS), Building Related Illness (BRI), and Multiple Chemical Sensitivity (MCS) are an expression of poor indoor quality. There is increasing literature demonstrating the link between building indoor environmental quality, and occupant health and productivity, driving the corporate real estate industry to investigate how to integrate wellness features into both new and existing building stock (McArthur, Jofeh, & Aguilar, 2015). Several human factors are influenced by facade retrofit- noise, glare, daylight availability, visual contact with the outside environment and other factors can all be influenced by facade in working environments (Martinez & Carlson, 2014). The proposed action of facade retrofit must evaluate reviving ventilation and lighting levels that will promote human comfort as a direct impact on indoor environmental quality. However, respecting human parameters for evaluation under significant criteria is a complicated task.

2.4.6 Rating systems of net zero energy retrofit of envelope Many types of rating systems set benchmarks in the form of standards or guidelines to measure the efficiency of the building on a specific scale (Kulkarni, 2011). There are four types of benchmarking techniques: Points-Based Rating Systems, Statistical Analysis (also known as Regression Model-Based) Benchmarking, Simulation Model- Based Benchmarking, and Hierarchal and End-Use Metrics. 1. Points-Based Rating Systems, including the U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) Rating System, do not allow comparisons against other buildings, rather, they provide standards and guidelines to measure how efficient and environmentally friendly a facility is and compared it to best-practice standards. A LEED score is made up of credits assigned for satisfying different criteria including energy efficiency and other environmental factors (Kinney & Piette, 2002). Existing Buildings Operations and Maintenance (LEED-EBOM) certification include improvement in the energy efficiency of the systems in the building. LEED-EBOM certification, a Points Based System, awards credit points by evaluating the performance based on the Energy Star® Rating of the building or by measuring the whole building energy consumption in case the building is not of a type eligible to obtain a rating (Kulkarni, 2011). Also, University of California (2013) mentioned the following rating systems: LEED for Commercial Interiors (LEED-CI) for renovation projects; LEED for Existing Buildings: Operations and Maintenance (LEED- EBOM) for the ongoing operational and maintenance practices in buildings; and, LEED for New Construction (LEED-NC) for new buildings and major renovations of existing buildings. 2. Statistical Analysis benchmarking, statistics for a population of similar buildings are used to generate a benchmark against which a building EUI is compared. This method requires large data sets to produce a reasonably sized sample of comparison buildings (Kinney & Piette, 2002). 3. A simulation model based tool generates an idealized benchmark using the available building details and a program like DOE-2 for simulating the building (Kulkarni, 2011). The potential of the integration of modeling and simulation activities for performance analysis of adaptive facades can be illustrated in a

number of different possible uses in the design and operation of buildings, Loonen et al. (2016) have reported these uses as following: . Informed decision-making to support the design process of buildings with specific adaptive building envelope components, in particular when an optimal performance is required across occupant comfort, economic and environmental aspects. . Prediction of energy-saving potential compared to a baseline design as part of green building certification schemes such as LEED and BREEAM; . Virtual rapid prototyping to evaluate different future-oriented systems/materials and identifying promising alternatives for further refinement and product development. . Exploration of high-potential control strategies that maximize the performance of adaptive building envelopes during operation. . HVAC system sizing and fine-tuning of the interaction between adaptive building envelope and other building services. . Virtual testing of the robustness of adaptive façade systems with respect to occupant behavior and variable weather influences. 4. Hierarchal and End-Use Metrics refers to the generation of benchmarks that link energy use to climate and functional requirements. This method is useful for accounting for more of the differences in features affecting energy use (Kinney & Piette, 2002).

To obtain the certificate as renewable energy certificate (RECs), the building needs should be occupied no less than 12 months with an occupancy rate of 75% or greater (Alkhateeb et al., 2016; The National Institute of Building Sciences, 2015). RECs are a credible and easy means to keep track of who can claim the environmental attributes of renewable electricity generation on the grid. Once a buyer makes an environmental claim based on a REC, the buyer can no longer sell the REC and the REC is considered permanently “retired”(The National Institute of Building Sciences, 2015). However, the building envelope retrofit requires careful planning. It needs to identify the areas that you want to improve. Envelope retrofits emerging technology in the construction industry associated with data required to accomplish the building energy performance

model. For example, date related to opening geometry (the ratio of glazing to the wall), and glazing thermal criteria as U-value, solar heat gain coefficient (SHGC) and visible transmittance (VT). Also, data related to external doors U value, thermo-physical properties of above and below grade walls (internal and external), floors, roofs, and construction type (Karaguzel & Lam, 2011). Thermal insulation, external shading devices and any kind of data manage the envelope technological adaptability that can affect the indoor air quality (Sharma, 2013).

2.5 NZE envelope retrofit technologies

This section is the answer to question no. two: What are the modern technologies used globally in achieving net zero energy principles in the existing buildings envelope retrofit? basically, Ma, Cooper, Daly, and Ledo (2012) have divided energy retrofit technologies into three categories: demand side management technologies, supply-side management technologies, and energy consumption patterns. The majority of these technologies related directly to the envelope. Albadry (2016) displayed the pros and cons of some technologies according to many authors. Buonomano, De Luca, Montanaro, and Palombo (2016) have displayed many innovative technologies for NZEBs. This section displays many emergent technologies that are used to achieve NZEB: Solar façade technologies, green walls, dynamic windows, nanotechnology, building physics, and building management.

2.5.1 Solar facades technologies Since Gaza has warm semi-arid climate according to Köppen classification, harvesting sun incident radiation is thankfully desired for fulfillment whether heating or cooling demands. The envelope contains solar façade technologies enable achieving net zero energy strategies in the existing buildings. Depending on the diversity of envelope configurations, two dominant parts are found. Solid and void parts need to deferent treatments for sunlight, airflow, visual penetration for occupants and users of buildings. For that, solar façade technologies are classified in two types: opaque solar facades and transparent or semi-transparent (translucent) solar facades (Quesada, Rousse, Dutil, Badache, & Hallé, 2012a, 2012b).

2.5.1.1 Opaque solar facades According to what type of the energy efficient strategies and measures that can be implemented to the solid facades, opaque solar façades are classified into two systems: passive solar facades, and active solar facades. Passive solar facades are construction systems that they do not need to machines or any mechanical interventions to capture the sun rays or to create air flow in between outside and inside the space. They are two types: a) thermal storage walls (TSW). b) The solar chimney (SCH). Firstly, TSW involves Trombe walls, phase change material (PCM), and thermal mass materials. Two main functions are available in a single unit. It has the ability to trap and store the solar heat. The heat flows through the wall penetrating to the inside air of the room and to the air cavity between the glazing and wall by radiation and natural convection. One of its basic is to reduce indoor air temperature swings (Quesada et al., 2012a). The new technology alternates a massive thermal mass of traditional Trombe wall with the latent heat loads from the PCMs phase-change processes. The global trend toward green and NZE buildings stimulates the construction industry to give an opportunity for using PCMS as a technique of diffuse indirect solar gain (Soares, Costa, Gaspar, & Santos, 2013). The basic of PCMs is to have a high latent heat of fusion, a high thermal conductivity, and having melting/freezing temperature in the actual range of application. Zhang, Zhou, Lin, Zhang, and Di (2007) have reported the advantages of the application of PCM in the buildings. Casini (2014) referred that these applications can be classified into two categories of micro- or macro-encapsulation. The latter can be found in a shape of tubes, spheres, panels as containers, while the former, polymer films are used as the container, and the diameter of these particles are less than 1 mm. They can be mixed with building products such as plaster, screed, concrete, gypsum, acrylic paints and wood products such as MDF. PCMs could contribute to achieving NZE. As shown in Figure (2.12), the sketch is as a thermodynamic system of NZEB. Taking into account that the envelope of the building is the boundary of the system wherever the balance occurs between on-site or footprint energy production and energy consumption. However, integrated PCM solutions not only rely on the climatic design but also on the amount and positions of these materials. Like these solutions essentially need to a detailed dynamic simulation of the thermal behavior of the building. Many authors

have investigated the potentiality of integrating PCMs in the envelope components in order to reduce the energy consumption in the building, therefore achieving NZEB. For example, Principi and Fioretti (2012) have used bricks with PCM were employed to increase the thermal mass. Also, Silva, Vicente, Soares, and Ferreira (2012) have investigated integrating clay brick with microcapsules PCM, as shown in Figure (2.13a). Alawadhi and Alqallaf (2011) have provided a schematic representation of a concrete roof with frustum holes filled with PCM, as shown in Figure (2.13b). Another passive strategy that can be used to ensure the energy efficiency of buildings by using passive design strategy, is to employ materials with thermal mass in their envelope. Three features defined the thermal mass are; specific heat, density, and thermal conductivity (Uribe, Martin, Garcia-Alegre, Santos, & Guinea, 2015). A tremendous energy saving will be achieved in the case of a combination of thermal mass and phase change materials (PCMs). In turn, the simulation tools play a great role to investigate and evaluate the thermal mass performance taking into account a range of parameters, the climate conditions, and the cost (Mirzaei & Haghighat, 2012).

Figure (2.12): Thermodynamic system of NZEB with the potential of integrating PCM

Source: (Soares et al., 2013)

a. Clay bricks with PCM b. a concrete roof with frustum holes filled with PCM Figure (2.13): Examples of PCM applications into a brick and concrete

Secondly, a solar chimney (SCH) is an element that uses wind-pressure for ventilation positively occurs when the building having atria or a shaft. This process is called stack-effect. An effective buoyancy occurs due to the differential temperature between indoor and outdoor. This will enable the cool outdoor air to replace the hotter air inside the building. Buoyancy increasingly can be influenced by the height of a shaft, the temperature inside the shaft or a lower pressure in the shaft due to the wind (Van Den Engel & Kemperman, 2012). Currently, many patterns of SCH were developed. For example, Wittkopf (2015) has chosen a solar chimney system and another envelope energy efficiency measures to achieve NZEB. A retrofit process conducted for three-storey building on the BCA Academy campus. In spite of the challenging of a hot and humid tropical climate, the solar chimneys are implemented for the natural ventilation of the classrooms and school hall as shown in Figure (2.14a). Also, Baba, Dieck, and Stephan (2011) have locally modeled a pattern of the solar chimney as shown in Figure (2.14b).

a. SCH of the BCA Academy campus b. Local potentiality of SCH Source: Wittkopf (2015) Baba et al. (2011) Figure (2.14): Examples of the solar chimney

The other type of the opaque solar facades is active solar facades which are the systems used gadgets for capturing the sun ray. They are building-integrated solar thermal systems (BIST), building integrated photovoltaic system (BIPV), and building-integrated photovoltaic thermal system (BIPV/T),

First of all, BIST is considered as an application of solar collection equipment that could be implemented into the envelope of the building. So, its function is both as one of the envelope components and as collectors of solar energy at the same time (Quesada et al., 2012a). Since BIST is a “multifunctional energy facade”, a wide range of architecture alternative design will be available for building envelope (i.e., color, texture, and shape). This flexibility effect not only improvement of the insulation but also the appearance of the building altogether (Zhang et al., 2015). The BIST system consists of a range of solar modular collectors in basis. The collectors absorb solar irradiation and convert it into heat energy. The circulation of heating/cooling depends on the integration of a heat pump cycle, a package of absorption chiller, a modular thermal storage, and a system controller. Unless the case of satisfied weather conditions, a backup/auxiliary heating system (e.g., boiler) is also integrated to guarantee the normal operation of the system (Zhang et al., 2015). Zhang et al. (2015) have classified BIST into three systems according to the heat transfer medium. They are air-, hydraulic- and PCM-based types. An example, Giovannetti, Kirchner, Sass, and Rockendorf (2016) presented a concept of BIST as panels, which combines an absorbing glass panel with a rear-mounted heat exchanger as shown in Figure (2.15). In addition, they provided a flexibility of the building envelope as cladding materials or as opaque glazing.

Figure (2.15): Example of BIST as cladding system

Source: Giovannetti et al. (2016)

Figure (2.16): Example of BIST as a balustrade cladding system

Figure (2.17): Envelope applications of BIST

Source: (Zhang et al., 2015)

Secondly, BIPV, the common use of BIPV is to achieve NZE in the existing buildings (Aelenei, Pereira, Gonçalves, & Athienitis, 2014). The photovoltaics system basically consists of elements of cells, connected mechanical items, and electrical items in order to control the PV power input. An electricity generation system is represented in a group of PV panels, batteries (for off-grid systems), charge controller, inverter and/ or export electricity meter (Haredy, 2016). Generally, two types of PVs have been installed in the buildings. They are polycrystalline and monocrystalline. The latter one is more efficient but has a high cost (Haredy, 2016). BIPVs have been divided into four categories photovoltaic foils, photovoltaic tiles, photovoltaic modules and solar cell glazing. The commonly PVs are made of Silicon materials. It is a combination of wafer-based and thin-film technologies (Petter Jelle, Breivik, & Drolsum Røkenes, 2012). PVs Silicon based cell is processed with negatively and positively charged semiconductors phosphorous and boron. When the sunlight strikes the photovoltaic cell, electrons freely flow from the negative phosphorus to the positive boron as shown in Figure (2.18), (Gaillard, Giroux-Julien, Ménézo, & Pabiou, 2014; Petter Jelle et al., 2012). Many properties are involved in evaluating the BIPV products such as solar cell efficiency, open circuit voltage, short circuit current, maximum effect and fill factor (Petter Jelle et al., 2012). PV products are foil products, tile products, and module products, as shown in Figure (2.19).

a. b. Figure (2.18): PVs Silicon based cell

Source: a. www.crystallinesolarpanels.com/sale-2471268-250w-polycrystalline-panels-photovoltaic- power-generation-system-22mw.html b. ze-engineer.blogspot.com/2013/10/what-is-photovoltaic-effect_7.html

a. foil products b. tile products c. module products

Figure (2.19): BIPV products

Source: a. www.altenergy.org/renewables/solar/solartechnolgy.html b.www.renewableenergyworld.com/ugc/blogs/2012/06/recent-development-in-building-integrated-photovoltaics- bipv.html c. img.diytrade.com/cdimg/1091921/11881289/0/1265097775/BIPV_MODULE.jpg However, Ghoneim (2015) has briefly displayed the PV storage of energy. During the daylight period, PV plants or PV array charges the battery. The charger regulator stops the process of charging when the battery is full. In turn, the battery supplies power to the loads whenever are needed as well as the situations of extended cloudy or at periods of increased load. The system involves a direct current (DC) inverter and an alternating current (AC) inverter in order to convert the direct current (DC) produced by the PV array to alternating current (AC) which is required by most household appliances. In case of the batteries are low, the electricity will power the AC loads in the building as well as the battery charger, as shown in Figure (2.20). Many specifications of the system are required: 1) The inverters capacity (in watts or kilowatts), their output voltage and their power quality. 2) Inverter cost per peak watt influences the choice of inverter size for a given system; PV output profile and the efficiency curve of the inverter. 3) To convert from DC to AC, most stand-alone inverters should incorporate some level of system control. 4) A quality stand-alone inverter will include a low-voltage disconnect and other system controls and will often serve as a battery charger. 5) Disconnect switches are needed for system servicing and personal safety. They are typically installed on the inverter's input and output, at the array output, and on the battery bank's output. 6) Most disconnect switches also include over-current protection, either as fuses or circuit breakers. The system usually requires a maximum power point tracker that monitors PV outputs such that the PV always operates near its point of maximum power along the IV curve.

Figure (2.20): Diagram of building integrated hybrid photovoltaic system

Source: (Ghoneim, 2015) As shown in Figure (2.21), PV arrays are interconnected with the external electricity grid via power electronic devices. Such devices include safety facilities. The main function of such power electronic units is the conversion of the PV DC power into alternating current (AC) which can be fed into a standard electricity supply grid. These power electronic devices are called “inverters” (Luther & Reindl, 2013).

Schematic of grid- connected medium power PV systems. (a) PV installation without on-site consumption of electricity; (b) System serving, in addition, on-site loads, (c) PV system without on- site consumption but additional electricity storage capability, (d) system as (c) with additional onsite loads. Figure (2.21): Schematic of grid-connected medium power PV systems

Source: (Luther & Reindl, 2013)

As a results, this study exhorts the Palestine Energy and natural resources Authority (PENRA) to find a new department that concerns about NZEB. This department should take care of putting regulations and laws that can regulate the process. In turn, it should be connected with Palestine standard Institution (PSI) in order to adjust the quality of process of NZE especially if it was related to retrofit. PENRA cooperated with PSI should be responsible about the quality of metrics that weighted what the energy will produce within the building to what it will be surplus going to utility.

Thirdly, BIPV/T, they are systems implemented wherever the temperature is a high and unfavorable for the performance of photovoltaic modules. Cutting down this temperature, a cooling fluid can be circulated to remove thermal energy from BIPV systems. Normally the fluid is water or air, as shown in Figure (2.22) (Pereira, 2015). Also, BIVT/T systems have classified into two categories according to what type of envelope part that PV models are covered. They are opaque and semi-transparent types. The applications of PV/T varied, but its concept is unified. Many researchers have interested in different topics related to PV/T. Fiorentini, Cooper, and Ma (2015) have described an innovative HVAC system with integrated PVT and PCM thermal storage for a net-zero energy retrofitted house. Also, Peng, Lu, Yang, and Han (2013) studied a prototype of PV/T that is mounted on a multilayer southern façade and compared with a normal wall as shown in Figure (2.23a). Moreover, Athienitis, Bambara, O’Neill, and Faille (2011) installed unglazed transpired collector which consists of the dark porous cladding. The concept of BIPV/T was applied to a full- scale office building demonstration project in Montreal, Canada. The outdoor air is drawn and heated into the DSF channel by absorbed solar radiation as shown in Figure (2.23b).

Figure (2.22): Schematic of working BIPV/T systems

Source: a. Peng et al. (2013) b. Athienitis et al. (2011) Figure (2.23): Examples of BIPV/T systems

2.5.1.2 Transparent and translucent solar facades Another use of PV in the envelope of the buildings. Here, more inventions are gathered in the architecture with market touches. Because of a need for architectural integration, BIPV (Building Integrated Photovoltaics) has been concerned by the market. As unique alternative glazing systems, semitransparent photovoltaic devices can offer an active-function of producing energy (Bizzarri, Gillott, & Belpoliti, 2011). Transparent and translucent solar facades involve passive solar façades: naturally ventilated façade (NVF). Also, they involve active solar façades: mechanically ventilated façade (MVF), the semi-transparent building-integrated photovoltaic system (STBIPV), and semi-transparent building-integrated photovoltaic–thermal system (STBIPV/T). Firstly, a translucent passive solar facade is a naturally ventilated façade (Bobrowicz, n.d). The natural ventilation takes place via supply, extract, or re-circulate the air through the building envelope (Quesada et al., 2012b). Double skin façade (DSF) is a method of achieving natural ventilation in the buildings (Farrokhzad, 2014). It is considered as a buffer zone that regulates the thermal extremes (Napier, 2015). Also, it achieves a higher airflow within the cavity by increasing its air temperature. For that, the outer layer should have a higher transmittance. To reduce the radiative and conductive heat, a higher thermal insulation is likely to be applied to the inner layer of the façade as double-glazing layer. This variety of glazing types is important to achieve a balance between the stack effect in the cavity and the heat transfer to the user room (Barbosa & Ip, 2014).

Moreover, DSF’s cavity allows installing shading devices as louvers and blinds to veil the sunlight (Napier, 2015). DSF is a beneficial energy retrofit approach since the second layer is an additional layer over the existing façade that it could be transparent (Kamel & Memari, 2016). In the case of net zero energy, an energy efficiency envelope is essential. Well-designed DSF could be a sophisticated element to reduce the energy consumption of the buildings by its interaction with the adjacent zones the environment as shown in Figure (2.24) (Ioannidis, Buonomano, Athienitis, & Stathopoulos, 2016). Moreover, DSF gives a chance of obtaining efficiently energy facade with integrating photovoltaics (PV) on the outer layer and implementing shading devices in the middle of the cavity. Regarding the flexibility in this type of facade, many ideas have been developed in term of its cavity’s size and the environmental operation of the system (Hong, Kim, Lee, Koo, & Park, 2013).

Figure (2.24): Well-designed DSF integrated efficient energy solutions

Source: (Mic Patterson & Matusova, 2013)

Secondly, transparent active solar facades, are the facades that can transfer direct solar heat gain into the building by absorbing and reflecting the incident solar radiation. In between of two translucent surfaces of the building envelope, a mechanically assisted ventilation system is utilized to supply, expel or re-circulate air within the cavity. It is called a mechanically ventilated facade (MVF). The heat is extracted from the cavity by the air in order to reduce the heating loads in the winter and cooling loads in the summer depending on the season and on the geographical zone (Quesada et al., 2012b). Cells or laminates PV modules are recognized as flat or flexible surfaces that can be applied to any surface of the building envelope. Many features are available in the STBIPV: its flexibility, the size, the shape, and the appearance that attracts the architects to incorporate it into other commonly used materials such as glass or metal either in opaque or semi-transparent surfaces (Frontini et al., 2013). Gaillard et al. (2014) have developed the prototype of a two-storey in order to meet both technical and aesthetic specifications. Vertical pleated tinted glazed facade with a diverse arrangement of photovoltaic cells electrically grouped into a vertical stack of three arrays. Installed on the west-north-west facade of an occupied office building in Toulouse, France as shown in Figure (2.25).

Figure (2.25): PV cells electrically grouped into a vertical stack of three arrays

Source: (Gaillard et al., 2014)

2.5.2 Vertical greenery systems In term of evapotranspiration, solar incident radiation converts into a latent heat, which prevents temperature to rise. For that, a full greenery façade is protected from the solar radiation that either reflected or absorbed by the plants’ leaf cover between 40% and 80% of the received radiation. It depends on the amount and type of greenery. On the other hands, the vegetation on high-rise façade is a new approach compared to rooftop greenery (Santamouris & Kolokotsa, 2016). Ottelé, Perini, Fraaij, Haas, and Raiteri (2011) mentioned that the greenery façade influences energy savings approach as well as the LCA assessment for the Mediterranean and temperate climate. The energy savings related to the cooling potential depending on the built-up greenery façade’s materials. VGSs can be concluded to three systems as shown in Figure (2.26): 1) The direct greening system: it has a very small influence on the total environmental burden, for this reason, this type of greening, without any additional material involved, is always a sustainable choice for the examined cases. 2) The indirect greening system: it based on a stainless-steel supporting system has a high influence on the total environmental burden; the choice of another material for the supporting system can lead to a sustainable option for the Mediterranean climate (thanks to the energy saving for heating and air conditioning). 3) The living wall system (LWS): it based on planter boxes has not a major footprint due to the materials involved since the materials affect positively the thermal resistance of the system. The environmental burden profile could be further improved by a higher integration within the building envelope (combining functionalities).

a. b. c. Figure (2.26): The Vertical greenery systems

Source: (Perini, Ottelé, Fraaij, Haas, & Raiteri, 2011)

2.5.3 Dynamic window DW The new paradigm of windows is to incorporate shading, motor, and sensors and control algorithm in one window. It is called a dynamic window DW as shown in Figure (2.27) that is another heterodoxy solution for NZEB whenever the reduction of energy consumption is very important. It is for both decreasing the heat losses during winter and reducing the solar heat gains during summer (Firląg et al., 2015).

Figure (2.27): A summary of the four sensor types of dynamic window

Source: (Firląg et al., 2015)

As shown in Figure (2.28), Sbar, Podbelski, Yang, and Pease (2012) illustrated how EC modulate sunlight and solar heat: . In the clear state, the EC glazing has a visible light transmission of 62% and passes 47% of the incident solar energy to the building interior. . When a low DC voltage is applied to tint the films, the amount of incident solar energy allowed into the building is reduced by 81%. The top layer of the EC film stack is a low-E coating (emissivity_0.15).

. When the films are tinted, they absorb solar irradiation, and the resulting thermal energy is re-radiated based on the emissivity of the films and the glass (glass surface 1 emissivity is 0.85). . Consequently, heat absorbed is selectively ejected to the exterior where it can be convected away.

Figure (2.28): EC technology in clear and tinted states

Source: (Sbar et al., 2012)

2.5.4 Nanotechnology Nanotechnology is a field that emerges an applied science and technology within the atomic and molecular scale -100 nanometers or smaller in the fabrication of devices or materials. In future, its potentialities likely to be more available in building machines and mechanisms with nanoscale dimensions (Casini, 2014; Love, Estroff, Kriebel, Nuzzo, & Whitesides, 2005; Purohit, Khitoliya, & Purohit, 2011). Also, producing uniform nanostructures are available with new shapes (spheres, rods, wires, half shells, cubes) and compositions (organics, metals, oxides, and semiconductors): as nanocrystals (Love et al., 2005). Two concepts are associated with nanotechnology: Positional assembly and Massive Parallelism. The former helps to get the right

molecular parts in the right places, and the later helps to keep the costs down (Purohit et al., 2011). In a matter of net zero energy and zero Carbon, adopting nanotechnology strategies reduces CO2 emissions by reducing energy consumption, utilizing renewable energy and implementing new technology sources in design such as green nanotechnology. By developing building materials that do not pollute, nanotechnology helps to overcome environmental issues (Omar & Sabsaby, 2014). (Brinker & Ginger, 2011) have taken care of displaying the applications of nanotechnologies in the energy field, in particular, generation and conversion, capture and storage, and efficiency and recycling. Briefly, it is crucial for an efficient building to employ clean energy technologies in order to obtain environment without pollutant. Nowadays, Nanoscience provides wide world technologies for energy efficiency applications that focusing on tailoring nanoscale manufactures such as photovoltaics, photochemical solar cells, thermoelectric, fuel cells and batteries etc. (Li, 2011).

2.5.4.1 Aerogel Aerogel is a solid Nano-porous material. An ultra-low-density material is obtained by desiccation of a gel - replacing the liquid component with a gaseous one. Aerogel looks like a solid foam with a tactile feeling close to foam rubber (Casini, 2014). Riffat and Qiu (2012) summarized the main benefits of aerogel as follows: (1) In order to achieve energy and cost savings, aerogel has perfect insulating properties since it contributes in reducing heat either loss or gain. (2) Aerogel provides a healthier indoor environment due to the removal of airborne contaminants. (3) Having the non- combustibility and acoustic properties, aerogel is used to retard heat and sound. (4) User-friendly, recyclable and reusable. Also, (5) Because of its low thermal conductivity, Aerogel can be applied to window panes and solar collector covers. (6) In addition to its non-combustibility and noise abatement, it can be used for adsorption and catalysis in indoor air purification, photo catalysis in environmental clean-up in fire retardation boards in kitchens (Riffat & Qiu, 2012). Aerogels applications in the building are divided into two groups: silica aerogels as insulation materials, and granular aerogel-based translucent insulation materials or transparent monolithic aerogel (Baetens, Jelle, & Gustavsen, 2011). Monolithic silica aerogels have higher solar transmittance than granular one’s applications (Berardi, 2015). Recently, aerogel

glazing has been paid attention due to their distinctive physical properties and energy performance in multifunctional building envelope component (Gao, Jelle, & Gustavsen, 2016). Regarding their low thermal conductivity that generally around 0.01-0.02 W/(m·K), silica aerogels are implemented for energy savings. It seems that the application of silica aerogels promise to be in highly insulating glazing systems (Berardi, 2015).

a. Sources: (as cited in Baetens et al., 2011) b. Sources: (Berardi, 2015) Figure (2.29): Aerogel glazing

2.5.5 Building physics for a sustainable built environment A part of building physics deals with dynamics of motion of gases (e.g. air) and liquid (e.g. water) of buildings (and their components), and things and people within and surrounding the buildings (Kapsalaki, 2013). Also, the ambient temperature is fundamental to evaluate the optimal cost-effectiveness measures in term of designing for a zero energy concept building (Causone, Carlucci, Pagliano, & Pietrobon, 2014). Then the potential of solar control, thermal control, and thermal zoning to identify what kind of strategies can be employed in either cooling or heating spaces. For instance, in case of cooling, this includes evaporative, cooling of outdoor air supplied to a building for ventilation (Attia, 2012). Attia (2012) has illustrated the inventory of passive and active solution sets for NZEB in hot humid climates as shown in Figure (2.30). However, the passive solar design is developed and re-evaluated the traditional techniques to be new technical knowledge and systems (Napier, 2015).

Figure (2.30): Passive and active solutions sets for NZEB in hot humid climate

Source: Attia (2012)

2.5.6 Building management & information system Generally, building management & information system (BMIS) is a system focusing on feedback operational data that related to occupancy comfort and energy

use. Instruments distributed in the building spaces collect these data. For instance, to measure temperature and humidity levels, sensors are installed within the building. These sensors are linked to a control algorithm that determines which building services equipment. They would be run or shut off. It is important to ensure that sensors accurately are taking measurements and that control algorithms correctly are calibrated (Boranian et al., 2013; Cao et al., 2016). Building management systems should be updated and kept up with the newest development of technology, automation, digital audio and video systems, and engineering equipment. Building systems that must be integrated into a single system management and monitoring: (1) Heating, (2) ventilation, (3) air conditioning, (4) heat supply, (5) power supply, (6) lighting, (7) including automatic and automated control of lighting. (8) fire protection, (9) video surveillance (10) telecommunications (telephone, LAN building with access to a global network, television) (Cao et al., 2016). In addition, three techniques and technologies character robustness of this system. The ability to render continuous feedback (quickly address operation problems through continuous monitoring), support regular maintenance programming (constantly track equipment maintenance), and finally support retro-commissioning (re-calibrate the system to maintain optimal performance given recent operational characteristics) (Boranian et al., 2013). The control devices either switches and knobs that enable users to manage the systems and to receive emergency and informational messages (Perlova, Platonova, Gorshkov, & Rakova, 2015). Cao et al. (2016) showed a typical application of a Building energy management systems BEMS in a ZEB home. The authors discussed controlling and scheduling strategies for NZEB. The smart grid meters should realize the interaction between buildings and national grids. These meters differ from a conventional grid. Taking into account the fluctuations in energy generation by renewable energy systems due to unpredictable weather situations.

2.6 The reasons for supporting the idea of NZE in the residential buildings sector: globally and locally

This category is to display why is it necessary for the world to convert their buildings – especially residential ones- to other energy efficient building as NZEB?

The general forecast of world energy consumption during the period of a 28-year period from 2012 to 2040 is to expand from 549 quadrillion British thermal units (Btu) in 2012 to 629 quadrillion Btu in 2020 and to 815 quadrillion Btu in 2040. It is account for 48% increase. About 50% of the total delivered energy consumed worldwide by commercial end users. Building sector divided between residential and households increasingly consume the energy for heating, cooling, lighting, and water heating excluding transportation uses. Many factors affect this consuming including Income levels, energy prices, building location, household characteristics, weather, equipment types and efficiencies, and energy-related policies. Non-OECD countries have a growing energy consumption in the residential sector by an average of 2.1% yearly compared with 0.6%/year in the OECD countries. This difference may be happened due to strong economic growth and expanding populations (U.S. energy Information Administration, 2016). On the other hands, Nowadays, fossil fuels such as coal, oil, and natural gas are commonly used for generating the energy. Consequently, greenhouse gasses are released into the atmosphere. CO2 (carbon dioxide) is one of the significant gasses contributing to global warming and climate change by absorbing and emitting infrared radiation. Some governments across the world have committed to reducing their greenhouse gasses emissions and increasing renewable energy production (UK building regulations and EU directives, 2014). The aforementioned reasons were much generally evidence which has been found in the whole of the world that encourages people or governments to focus their efforts towards the sustainability as NZEB not only at local level but also at national level. However, some countries have regulated the energy efficiency of the building has many constraints. For instance, on the residential scale, in order to obtain zero energy homes, the U.S. Department of Energy Research recommends methods to get to 70% efficiency with restrictions of roof areas for solar domestic hot water (SDHW) and photovoltaics (PV) to meet the remaining loads (ASHRAE Vision 2020 Ad Hoc Committee, 2008).

2.6.1 Why NZE retrofit could benefit Gaza residential buildings Locally, population density in Palestine is generally high particularly in Gaza that is due to the concentration of about more 1.8 million people in an area not exceeding 365 Km2. Most of them are Palestinian refugees who were immigrants from their

villages and towns that were occupied in 1948, in addition to, the normal increment of the population that characterized the Palestinian community resident. The density- estimated population for the year 2016 is about 800 persons per Km2, indeed about 5.514 person per km2 is in Gaza with average 3.3% yearly. 71.8% household lives in apartments. This raises the density to 19.3% (3 persons or more per room) in the high- rise density areas. 93% are connected to the source grid electricity (State of Palestine, 2016a). The growing demand for electricity is due to population growth accompanied by urban growth and increasing projects that require energy usage, which leads to increase the pressure on the electricity network. There is only one plant of electricity in Gaza, which depends on diesel fuel imported from Israel, it produces about 403- megawatt hour which represents 8% of Palestine purchases of electricity and accounted for only 23% of Purchases Gaza of electricity as in the year 2013 (State of palestine, 2016c). Moreover, the number of hours of electricity cut up for long hours during the day. It leads the price of a kilo of electricity to rise when the amount is less than required. The main reasons are a higher generation, transmission and distribution costs. These made the availability of electricity and the price of a kilo undergo the political and economic variables, therefore, they influenced both of the electricity supply and increased demand (Safi, Migdad, & tawil, 2014). Aforementioned problems have made the decision makers and people finding an alternative method to offset the shortage of electricity such as Uninterruptible power supply UPS.

2.6.2 Review of the Palestinian energy sector The main forms of energy used in Palestine are: 1) Petroleum and its derivatives such as gas, gasoline, diesel, and kerosene. 2) Electricity power. 3) Renewable energy sources: solar energy, biomass, coal, firewood, and wind (State of palestine, 2016c). Palestine has the third fastest growing population (+2.9% per annum) in MENA during the last decade. The fast-growing economy should positively influence future investments in EE actions for the industrial and commercial sectors. Among MENA countries, Palestine ranks first in primary energy intensity, which indicates a relatively low consumption of energy and as a consequence, a possible difficulty for reducing this consumption through EE actions in the residential sector. This is particularly true for Gaza where suppressed demand reaches a very high level. However, there should

be room for improvement in Palestinian households. With 34%, electricity has the largest part of the Palestinian energy mix. Furthermore, the residential sector accounts for 60% of the consumption. This shows that concentrating EE actions on the residential sector should have a large impact on final consumption. Palestine is the MENA country with the highest use of Solar Water Heaters (SWH). 56% of households have a SWH system on their roof. However, one-third of these systems are out of order. Moreover, distribution losses (technical and non-technical) reach a very high level (20-30%). A significant reduction of these losses would be of paramount importance for the nation. The price of electricity, based on IEC retail tariff, is very high in Palestine. As a consequence, the share of electricity in Palestinian household expenditures (9%) is the highest within MENA countries. Any EE action reducing consumption should have a short return on investment. However, for selecting the most appropriate actions, one needs to know what the future consumption will be during 2020-2030 and, if possible, by usage of electricity (The World Bank, 2016). So, According to the situation of population and energy situation in Gaza, there is an imperative need to find an efficient method not depending on fuel to generate the electricity. So, NZEB concept could be a wright solution both of building owners and decision makers. But, the process of NZE retrofit cannot be performed without knowing the optimum solution that consists of many energy measures that can reduce energy consumption on site (net site energy) with less economic cost. This step is called assessment of cost-effectiveness, see category 2.4. Summary: This literature review investigated many approaches to implementing NZE strategies in existing buildings. In particular, the envelope has an influencing role in the retrofit process. Many measures have been employed in order to reduce the energy demands and CO2 emissions in the buildings. Simulation tools have examined the relationship between retrofit measures and the envelope of the buildings. Also, there is a hope to attract both people and decision makers to make use of what retrofit technologies have. There is a potential to employ some of these strategies on Gaza buildings. Taking into account the necessity of implementing the tools that stimulate people toward energy saving such as motivations. On the other hands, open-minded possibilities of technology enable the building industry to discover many methods and

materials to achieve the energy savings in the building and also gets NZEB. However, unfortunately, Gaza has a limited opportunity to capture and to get as these technologies or materials because of the siege. But, the chance is possible by using local inventions and encouraging local efforts. So, this study induces PENRA to promote the concept of NZEB and NZER by holding an awareness campaign to encourage owners to convert their buildings to an energy efficient building especially if they are multi-storey buildings. Admitting rating system for RES certifications such as LEED-EBOM certification, therefore, Find rewards and incentives to motivate owners to adopt NZE in their building as well as loans, or economic prevailing. Also, the study recommends to using optimization tools to estimate the appropriate incentives for NZER process such as BEopt provided by LBNL. Also, PENRA should polarize experts of NZER to make use of their experience of retrofit projects. It should reinforce the cooperation with the private sector to promote the idea of NZER. Moreover, it should provide technical support for individual retrofit projects. PENRA should encourage the local industry to produce qualified materials for NZE such as PCM, products of BIPV, nanotechnology as aerogel. Therefore, they would be rewarded to keep up with the new technologies. Find green infrastructure that buildings could be connected with in order to complete the image of energy savings in whole Gaza.

Chapter 3 Methodology

3.1 Research design

The study based on the descriptive analytical method. It is divided into two phases: theoretical and analytical. Regarding the theoretical phase, it concerns identifying issues related to the subject of this study. Moreover, clarifying the tools used globally in assessing thermal performance of the buildings. In addition, in order to achieve the objectives of this study and to achieve net zero energy principles on existing buildings in Gaza, the research identifies the latest technological tools and materials in this context. Also, using the descriptive approach of similar previous existing case studies that follow certain strategies in achieving NZEB, to identify the adopted concepts, materials, and tools in these cases through collecting information from new international researches in order to make use of their procedures. On the other hands, the study uses an analytical approach that depends on DesignBuilder simulation tool in applying many scenarios that can be applied to achieve NZE principles to improve the thermal performance of the existing multi- storey residential building in Gaza. Currently, the simulations computer-aided tools, proved their possibilities in accomplishing low energy methods in buildings. Energy measures package is evaluated. They are: U-value, shading devices (SHDs) and shading coefficient SC, air tightness, green roof, and ventilation. HVAC systems are comparable with the envelope of the building using SHDs, double skin façade (DSF), and vertical greenery system with DSF (GDSF) in addition to other cases of combinations of DSF and GDSF. HVAC involves using the main shafts of QEAB by using stack effect, wind catcher WC, glazing skylight using CFD. The next step is to generate energy by renewable energy sources (RES) depending on footprint and on- site generation. Both of the delivered energy and the exported energy are weighted. As a Surplus going to grid. Then, optimization step, cost optimal benefit step to tradeoff between our measures to get the optimal solution for NZEB for QEAB. The findings help to put main lines for strategies that may benefit architects and decision makers in Gaza to get energy efficiency in the existing buildings. Then, findings are discussed in

the research to come up with the recommendations that are related to NZE retrofit as strategies.

3.2 Research population

The population of this study is all the residential multi storey building in the Gaza Strip. According to Palestine building code, the multi-storey building is a building that has the height of over 20 meters for residential buildings and 22 meters for commercial buildings (Kahloot, n.d). Meanwhile, Census book of 2015 of Palestinian Central Bureau of Statistics (PCBS) has defined the percent of households that are living in flat are 53.7% in west bank and Gaza Strip. 71.8% of households in Gaza Strip are living in apartments. As such, the population who can benefit from the results of this study are around 287,200 households in case the average of family members are 5 person.

3.3 Target population

To overcome the problem of increment population, Gaza constructs multi-storey buildings as a shelter, as mentioned in chapter (2) category 2.6.1. For that, the target population in this study is Al Quds Engineers Apartment Building QEAB as a multi- storey building, as shown in Figure (3.1). Regarding Palestinian code, the multi-storey building is a building that has the height of over 20 meters for residential buildings and 22 meters for commercial buildings (Kahloot, n.d). The building is located in the western side of the Salah Alden Street. Also, it is situated in western of Gaza city in Tel Al Hawa neighborhood. Tel al Hawa neighborhood is bordered by Al Aqsa Street in the east, Own Al-Shwwa Street in the south, Cairo Street in the north, and Al Rasheed street in the west. The building is close to Mediterranean Sea Coastline about 500 m. The terrain was supposed that exposure to wind was suburban assumed in DB. QEAB has been built since 2005. But, it was really occupied in 2011. It faces to Al Quds Street. The building has a one ground floor and eight other floors. The ground consists of four stores and rare opened hall. The building is served by two upstairs. One for vertical circulation, the other is for emergency escaping. Each floor consists of four apartments. Because of its symmetrical apartments in all directions, NE, NW,

SE, and SW, the building is chosen for this study. Also, the symmetry plans forms for apartments and shafts are commonly used in the residential multi-storey buildings in Gaza. Such building form resulted from Gaza urban planning. Also, this building has two main shafts whose area is 10.45m2 in each. These shafts provide daylight and ventilation for many facilities that overlook them. The only disadvantage of this building that its windows areas are big even though the windows located into in the southern elevation.

a. QEAB location in Gaza Strip and Gaza city b. Front shot of QEAB

Figure (3.1): Al Quds engineers apartment building (QEAB)

3.3.1 Baseline case parameters As shown in Figure (3.2). Each floor contains 4 apartments. The area of each apartment is approximately 132.9m2. Each apartment consists of master bedroom, two bedrooms, open kitchen, bathroom, living room, balcony, and guest room with W.C. The total area of the building is 4252.96m2. The height of the building is 29.4m. The glazing ratio is 22%. Total area of walls is 2540m2.

a. Typical plan

b. Legend of the name of zones according to their direction. Figure (3.2): QEAB plans

Uninsulated external walls are made up of 15 cm cement masonry units (CMU) with two-sided painted plaster. Internal partitions are made up of 20 cm CMU and 10 CMU. Also, windows are made up of 3mm frosted glass with no thermal break. For thermal calculations in this study, each apartment has been considered as one thermal zone. Each zone was named regarding its direction such as zone NW, zone NE, zone SE, and zone SW throughout the eight floors, as shown in Figure (3.2). Balconies were considered as non-thermal zones, and so were the upstairs. The calculations were conducted by using mixed mode ventilation with thermostat temperature ranged between 19-27℃. The general assumption was that the building has medium airtightness case. In fact, the majority of energy consumption in QEAB generally happens by space cooling and heating, and domestic hot water as found in Gaza generally, is about 100.820, 48.851, and 143.782 MWh respectively, as shown in Table (3.1). The total electricity demand that the building uses is about 524.719 MWh annually. Table (3.1): The consumed energy (MWh) by the baseline case

Room Heating Cooling DHW Electricity Lighting Electricity (Electricity) (Electricity) (Electricity) 169.794 61.472 48.851 100.820 143.782 524.719 Source: DB. Note: Room electricity is the electricity that consumed by room equipment other than lights (computers, equipment, process etc). The general assumption in this study was an exaggeration daily usage - full occupancy for 24h. In case of Gaza, neither duration of electricity nor time is known. The reality, the duration of the electricity does not exceed 4 hours sometimes a day. This is not enough for doing daily errands completely.

Internal sensible heat gain was calculated regarding CIBCE guide in 1988 vol. (A&B) as cited in (Asfour, 2014). An exaggeration usage is assumed here. Total sensible heat gain was 7.5 W/m2 per each zone, as shown in Table (3.2). It is important to mention that achieving NZE could be taken apart when the building has the ability to minimize its energy consumption in addition to its ability to generate electricity by using renewable energy sources (RES). Referring to Figure (2.9), applying NZE basics to the case study building starts with obtaining energy efficiency to the envelope and then to get the balance between what the building receives from the utility (supply) and what it produces using renewable energy sources. Table (3.2): The internal sensible heat gain for each zone

number watt total watt operation period total watt/m2 Lights 20 40 800 50% 400 Personal computer 1 200 200 50% 100 TV 1 150 150 50% 75 Refrigerator 1 50 50 50% 25 Microwave 1 2000 2000 5% 100 Kettle 1 2000 2000 5% 100 Oven 1 2000 2000 5% 100 Washing machine 1 1000 1000 10% 100 8200 1000 7.5 Source: (Asfour, 2014) Sanguinetti (2012) in her Ph.D. thesis has suggested further divisions of the refurbishment practices for façades as replacement of the façade components, adding new components to the façade, and adding new layers to the façade. On the other hands, Kaluarachchi et al. (2005) defined that façade retrofit strategies have been classified according to the construction type, the spacing between the façade layers, and the system ventilation parameters. Here, in this study, retrofit strategies in QEAB have depended on energy package that consists of five energy measures which were applied to its envelope in order to get NZEB. The optimization package involves overall U-value, shading devices (SHDs) and shading coefficient (SC), airtightness, the green roof (GR), and ventilation. As for natural ventilation, the analysis was conducted separately by using summer and winter week design that is available in DesignBuilder V5. Natural ventilation setpoint was 25ᵒC. Also, AT was controlled by calculated natural ventilation. When using the calculated natural ventilation model option, windows and vents are only opened when: AT is above the cooling setpoint temperature, or it is greater than the outside air temperature. The attention was

concentrated on an indoor air temperature (AT) - By default, EnergyPlus assumes that air temperature within a zone is completely uniform i.e. the air is fully mixed, outside dry bulb temperature (DBT) depending on Al Arish weather data file, as shown in category 3.3.2 Also, the radiant temperature (RT) - the calculated mean radiant temperature (MRT) of the zone, calculated assuming that the person is in the center of the zone, with no weighting for any particular surface - was concerned in (DesignBuilder V5). Fresh air flow (FAF) - the sum of outside air (in ac/h) flowing into the zone through 1) The HVAC air distribution system, 2) Infiltration and 3)

Natural ventilation. SHGW is solar gains through the external windows. In case of mechanical and mixed mode ventilation, comfort band was in between of 19-27ᵒC.

3.3.2 Weather data and Psychometric chart First of all, to perform the thermal simulation and analysis, weather data of Gaza should be evaluated. This forward step is to identify the climatic factors that affect energy consumption in the building, then having the ability to evaluate the selected energy measures, see category 2.3.3 in chapter (2).

3.3.2.1 Gaza climate Gaza is bordered by the Mediterranean Sea in the West and the Negev Desert and the Egyptian Sinai Peninsula in the south. Gaza area has a length of 45 km from Beit Hanon in the north to Rafah in the south. It is divided into five Governorates: the north, Gaza city, Middle, Khan Younis, and Rafah (Mogheir, de Lima, & Singh, 2009; Rabou, 2011). Gaza Astronomical location is (31º25’N, 34º20’E) that has approximately 365 km2. In fact, Astronomical location affects the amount of solar incident radiation on any area of the earth. In term of sunshine in Gaza, it is about fourteen hours long in the summer day, while the hours of sunshine is about ten hours in the winter day. For that, the temperatures in the summer are higher than the winter (Thabit, 2011). Köppen climate classification has indicated that Gaza has warm semi- arid climate (BSh), as shown in Figure (3.3). The warm semi-arid climate tends to have hot, sometimes extremely hot, summers and mild to warm winters. Snow rarely (if ever) falls in these regions. Hot semi-arid climates are most commonly found around the fringes of subtropical deserts (Wikipedia, 2016a). However, it is rare,

especially for Gaza, to find weather data that can facilitate the process of simulation due to specialists depending on external sources to identify the weather forecast.

Figure (3.3): Köppen climate classification

(Chen & Chen, 2013) For that, the simulation in this study was carried out by using Al Arish weather data that has nearly a same weather as Gaza. It is located on the latitude of 31.1⁰ North and longitude of 33.8⁰ East. The wide range of weather data was provided by using a weather tool of Climate Consultant 06 which is available in http://energy-design- tools.aud.ucla.edu. This tool displays a variety of graphic representation of hourly climate data and could visualize the pattern and details that characterize any climate zone. It could use an outdoor condition to provide an indoor comfort that helps to make a general assumption about building design. Its calculations depend on ASHRAE standard 55 handbooks. The Thermal comfort is based on dry bulb temperature, clothing level (clo), metabolic activity (met), air velocity, humidity, and mean radiant temperature MRT. Indoor ambient is assumed that mean radiant temperature is close to dry bulb temperature. The zone in which most people are comfortable is calculated using the PMV (Predicted Mean Vote) model. In residential settings, people adapt clothing to match the season and feel comfortable in higher air velocities and so have wider comfort range than in buildings with centralized HVAC systems. Gaza has semi- arid climate as well as AL Arish. The sunniest days are found in June in which the sky is not cloudy and the destination location is exposed to direct solar radiation above 700 wh/sq.m on average. While the average dry bulb temperature is ranged between above

30 ⁰C in summer and below 10⁰C in winter. One can see that the sun is the most renewable source of energy that is available in Gaza. Moreover, above 20⁰C is an average of wet bulb temperature which is found in summer whenever the humidity of air raises, while it is below 10⁰C in winter. Regarding tool of Climate Consultant 06, the designing annual dry bulb temperature DBT is shown in . Figure (3.4). A maximum value of DBT is 37.5⁰C in September. A minimum value is 20.9⁰C at the day in January. At night, it ranged from 18.3⁰C in summer and 4.1⁰C in winter. Daily dry bulb temperature is ranged between 27.26⁰C in August (summer) and 13.27⁰C in January (winter).

3.3.2.2 Psychometric chart In addition to what mentioned before, Figure (3.5) shows the thermal comfort band that is sited in between 20⁰C and 30 ⁰C in both summer and winter. However, thermal comfort is the state, which minded, expresses satisfaction with the thermal environment that associate to ambient factors like air temperature, humidity, and others as well as to personal factors (clothing insulation, metabolic heat). In addition, it plays a significant role in human health and well-being. Much warm feeling occupants can cause a feeling of fatigue, while much cold feeling can cause a feeling of anxious and inattentive. Furthermore, highly heat temperatures negatively affects the health of occupants suffering from diseases such as cardiovascular, diabetes, Parkinson’s, Alzheimer’s and epilepsy, whereas high excess cold and mold in homes lead to asthma/respiratory illness and affects negatively the mental health of the occupants (Kunkel & Kontonasiou, 2015; PEC, 2004).

Figure (3.4): Dry blub temperatures

Figure (3.5): Psychometric chart using ASHRAE standard 55-2004

For Thermal comfort circumstance, DesignBuilder finds a calculator for thermal comfort indicators as shown in Figure (3.6). The operative temperature is defined via DesignBuilder itself (DesignBuilder V5). Operative temperature accounts for the average of the air temperature and the mean radiant temperature (MRT). MRT is assumed that the temperature of an object inside the zone is not affected by the temperature of surrounding surfaces. As well as ASHRAE Standard 55, the thermal comfort is based on dry bulb temperature (DBT), clothing level (CLO), metabolic activity (met), air velocity, humidity, and mean radiant temperature. The zone in which most people are comfortable is calculated using the PMV (Predicted Mean Vote) model. In residential settings, people adapt clothing to match the season and feel comfortable in higher air velocities and so have wider comfort range than in buildings with centralized HVAC systems. For example, thermal comfort circumstance at 23ᵒC are as follows: clothing is 1.1, airspeed is 0.5m/s, relative humidity is 60%, and activity level is 1. PMV (Predicted Mean Vote) is -2.8\% which sited between +0.7 and -0.7 (regarding Palestine green council guide) which indicated to percentage predicted value is 6.62%. After estimating the values of clothing level, air temperature, and MRT, thermal comfort conditions were recognized to perform our energy analysis to the baseline case of QEAB. Energy package was applied to the building to reach the goal of this research of NZE.

Figure (3.6): DesignBuilder thermal comfort calculator

Finally, the climate consultant tool offered many solutions to overcome hot climate hardness, as shown in Figure (3.7). All design strategies were offered depending on passive solutions such as minimize or eliminate west facing glazing to reduce summer and fall afternoon heat gain; Figure (3.7a), window overhangs (designed for this latitude) or operable sunshades (awnings that extend in summer) can reduce or eliminate air conditioning; Figure (3.7b), use plant materials (bushes, trees, ivy- covered walls) especially on the west to minimize heat gain (if summer rains support native plant growth); Figure (3.7c), and shaded outdoor buffer zones (porch, patio, lanai) oriented to the prevailing breezes can extend living and working areas in warm or humid weather; Figure (3.7d).

a. b.

c. d. Figure (3.7): The climate consultant solutions offered for the semi-arid climate

However, this study takes care of using shading devices, wind catcher, (stack effect), double skin façade, and a combination of double skin façade and vertical greenery system.

3.3.3 Modelling cases setup As shown in Figure (3.8), the thermal analysis in the study takes place by defining the parameters of the baseline case and then looking for about how to control the energy consumption by reducing the space cooling and heating for the building. Five energy measures were examined in order to achieve NZE of an existing building. U- value, shading devices and shading coefficient, air tightness, green roof, and ventilation. Taking into account that thermal comfort setting using the psychometric chart of ASHRAE standard 55-2004 and 2010. The process is accomplished by generating the electricity using on-site renewable energy generation. The cost- effectiveness is carried out to define which measures are most cost benefit to getting NZEB in the multi-storey existing buildings.

Figure (3.8): Modelling cases setup

3.4 Sampling of floors

The study chose many options of zones to achieve the aim of the study. To study the overall U-value of the envelope, the selected floors are first, second, fourth, sixth,

and eighth floors in order to predict the effect of this measure on the building totally. Then, case 06 – as shown in Table (4.1) - is selected to examine the following energy measures. It is the more realistic case because of its cost and its weight on construction. For shading devices, shading coefficient, and airtightness, zone L1-SW, L4-SW, and L8-SW are selected. All zones are selected because they face the south direction. Also, L1-SW is selected due to its position above the opened ground floor. Sapian, Majid, Hanita, and Hokoi (2012) clarified that the lower range of internal air velocity is preferred for thermal comfort while the open ground floor increases the internal air velocity performance due to the fact that sufficient airflow cannot be expected near the ground floor of high rise buildings. L4-SW was chosen due to its middle position in the building. L8-SW was chosen because it locates on the last floor. For the same reason, L8-SW is selected for green roof measure study. The Fifth floor is chosen for shading coefficient and ventilation because it locates in the middle part of the building. CFD simulation concentrates on the whole building in order to observe the indoor air behavior. To be compatible with the ventilation study, the fifth-floor is selected for the age of air. For on-site RES generation and evaluating the cost-effectiveness, the whole building is intended to be selected. This was to define which scenario has the lowest net site energy, therefore, more energy savings.

3.5 Research tools

In order to achieve the objective 1 and 2, the study makes use of literature review. DesignBuilder V5 is used to achieve objectives 3, 4 and 5, as shown in Table (3.3). DesignBuilder is a user-friendly modeling environment where you can work (and play) with virtual building models. It provides a range of environmental performance data such as: annual energy consumption, maximum summertime temperatures and HVAC component sizes (DesignBuilder 2, 2009).

Table (3.3): The brief exhibition of the methodology of the study

questions objectives tools What are the worldwide Identify the worldwide tools and tools and systems used to systems used to assess the energy Literature evaluate the energy efficiency of building envelopes review efficiency in the envelope

retrofit of existing retrofit. buildings? What are the modern Find out the modern technologies technologies used globally used globally in achieving net zero in achieving net zero Literature view energy in the envelope retrofit of energy principles in the existing buildings existing buildings. envelope retrofit? Propose scenarios for the What are the proposed rehabilitation of the envelopes of scenarios for the envelope the existing multi-storey retrofit of multi-storey DesignBuilder residential buildings in Gaza in Simulation tool residential buildings help order to obtain a net-zero-energy in obtaining net-zero- building. energy buildings?

What are the proposed Propose scenarios of ventilation scenarios of ventilation using the building envelope as a DesignBuilder using the building Simulation tool retrofit process in Gaza in order to envelope in Gaza in order to get NZEB? get NZEB. Propose scenarios of RES What are the proposed DesignBuilder scenarios of RES generation in Gaza in order to get Simulation tool generation to get NZEB? NZEB.

3.6 Simulation Tools and Validity

Broadly, finite element method is an essential approach that has been developed to accomplish and perform thermal analysis in the newest projects and so is in retrofit ones. At first, DesignBuilder and Ecotect were used simultaneously as much to

examine many of refurbishment works thermally. In the case of NZE, DesignBuilder is a familiar program that many studies applied since it has the ability to analyze multi- objectives of energy performance in one building or in a set of buildings. To obtain high quality and comfortable buildings incorporated with many features as complying with regulations, DesignBuilder could dominate many different criteria and balance between them in addition to minimizing cost, optimizing on-going energy costs and reduce environmental impact. Moreover, advanced energy simulation with modeling technology on the market is combined occasionally for both architects, engineers and energy assessors. Also, DesignBuilder provides a graphical user interface to the EnergyPlus simulation engine. It is developed to be used in all design stages. Here Version-5 was used for this study. Although DesignBuilder is based on a complex simulation program, it attempts to address the architect’s specific language by a visual oriented interface and inputs in different levels of detail. Nevertheless, the output constitutes one of the major limitations concerning architect-friendliness. The parametric analyses, on the other hand, could provide useful information to support architects in the design of NZEB (Attia, 2011). Moreover: regarding (DesignBuilder V5) guideline, DesignBuilder enables you to (1).Easily compare design alternatives. (2) Optimize your design at any stage with client’s variable objectives. (3) The model even complex buildings quickly. (4) Effortlessly import existing BIM and CAD design data. (5) Generate impressive rendered images and movies. (6) Simplify EnergyPlus thermal simulation. The study has used also Ecotect program. ECOTECT is primarily intended to be a conceptual design tool and incorporates various simulation functions. The target audience is architects and designers. ECOTECT 2011 was tested for this analysis. The tool’s major strengths are its visual appearance and suitability for early design stages. However, there is a lack of accuracy and reliability for thermal analysis. Also, too many options and too much information are incorporated. Further, ECOTECT does not sufficiently embrace the NZEB-approach, as it does not assist architects in implementing renewable energy strategies (Attia, 2011).

Chapter 4 NZER of the building envelope in Gaza

Chapter 4 NZE retrofit of the building envelope in Gaza

Introduction

Obviously, electricity sector in Gaza suffers a real catastrophic situation. It affects the whole life fields dramatically. Simultaneously, natural incremental population –as mentioned before- makes the authorities to permit and encourage people to build high- rise buildings as shelters which account for housing associations. Multi-storey buildings predominate urban areas as well as residential settlements. The main issue in this chapter is how to achieve energy efficiency for QEAB via its envelope as a first step to obtain NZEB as mentioned before in page (27). So, the researcher concerned on how to employ building envelope in the existing building to achieve NZE in Gaza. Many energy measures involve overall thermal transmittance (U-value) for external walls, local shading devices, shading coefficient, air tightness, and green roof. Deng, Wang, and Dai (2014) mentioned that a good passive design for the building, which may include optimized orientation, high-performance thermal-isolation envelope, good tightness and well-designed shade for windows, generally decreases the thermal and electrical load of buildings. In this context, this chapter is the answer to question no. three: What are the proposed scenarios for the envelope retrofit of multi-storey residential buildings help in obtaining net-zero-energy buildings.

4.1 NZE retrofit measures evaluation

From its definition, NZE depends on what kind of materials are available in the destination place. It means to use the prevailing construction method and materials locally. The most kind of method that is used in constructing buildings in Gaza is that depend on CMU for external walls even though in internal partitions. So, the first step toward achieving NZEB goals in Gaza was to investigate the overall U-value constraints according to Palestine energy code (PEC). Secondly, investigating the shading devices and the role of shading coefficient (SC) possibilities to reduce the energy consumption due to space cooling and heating in the building. Thirdly, the role

of airtightness in the energy consumption has been paid attention in order to minimize the penetrating of heat flow inside the building. Fourthly, the green roof has its luminosity on the same subject. The outcomes of this chapter will be used in the next chapters.

4.1.1 U-value In this study twelve cases were suggested for overall U-value as a first step toward achieving NZE in QEAB. At first, the process of the selection of these cases was chosen to take into account that Palestine energy code has restricted the overall U value of walls, glazing and doors areas altogether to be 1.8 w/m2.k. Moreover, some of these cases were extracted from Muhaisen (2015) which studies is the effect of wall thermal properties on the energy consumption of buildings in the Gaza Strip. Table (4.1) displays the configuration of those cases and their dimensions. Also, Table (4.2) displays their thermal properties. Meanwhile, the insulation layers and air gap thicknesses were defined by DesignBuilder V5. Their thermal properties were defined by using Palestinian energy code (PEC). Also, The thermal properties of existing construction elements materials were calculated in appendix (1), Table (appx 1.1). U- values of built components were 2.64 w/m2. k for external walls, 6 w/m2.k for windows, and 3 w/m2.k for the doors. Overall U-value was 3.37 W/m2. k. However, The overall U-value of the examined new cases which was calculated to be what is restricted by PEC (2004) as Equation (4.1):

퐴 푤𝑖푛 퐴 푤 퐴 푑 푈푎푙푙 = ( ) 푈 푤푖푛 + ( ) 푈 푤 + ( ) 푈 푑…………………………….... EQ (4.1) 퐴 푎푙푙 퐴 푎푙푙 퐴 푎푙푙

Where U all: the overall thermal transmittance of the windows and walls altogether measured by w/m2.k. 2 A win: the area of windows measured by m U win: the thermal transmittance of the windows measured by w/m2.k. 2 Aw: the area of walls measured by m Uw: the thermal transmittance of the walls measured by w/m2.k. 2 Ad: the area of doors measured by m . 2 Ud: the thermal transmittance of the doors measured by w/m .k.

Aall: the total area of windows and walls and doors.

The area of doors and its U-value dealt with as a constant value, but the target value of U was demonstrated by the U-value of windows and walls simultaneously. The total area of windows was 18m2 and opaque area was 57.4m2 for each zone. The majority of cases were depending on concrete masonry units (CMU) due its trendy in Gaza. The thermal simulation was carried out by using DesignBuilder V5. The validation was accomplished by using Ecotect 2011 thermal analysis program. The ventilation was assumed to be mixed-mode ventilation. Comfort band was between 19-27 ᵒC Moreover, The first floor, second floor, fourth floor, and eighth floor were both tested to estimate the cooling and heating loads taking into account the direction of the apartment. Basically, the U value has been affected by two main thermal terms: the thickness of the materials and its conductivity (Šadauskiene, Buska, Burlingis, Bliūdžius, & Gailius, 2009). Table (4.1): The examined cases of walls and glazing

Wall U value Galzing U value Glazing Wall U value Galzing U value Glazing Wall U value Galzing U value Glazing 1.45 2.67 type 1.51 2.47 type 1.43 2.72 type Overall U value = 1.8 W/m2.k Overall U value = 1.8 W/m2.k Overall U value = 1.8 W/m2.k

Case01 Case02 Case03 INSIDE

INSIDE

INSIDE OUTSIDE

OUTSIDE

Air

spacing

side Out In side Out In side Out In

Dbl Clr 3mm/13mm Air

dim (mm) 30 150 50 120 20 6mm double glazing 16mm dim (mm) 30 200 48 100 20 dim (mm) 30 200 50 100 20

materials* CP HB AG HB CP materials* CP SB AG HB CP Dbl LoE (e3=.1) Clr 3mm/6mm materials* CP HB AG HB CP Wall U value Galzing U value Glazing Wall U value Galzing U value Glazing Wall U value Galzing U value Glazing 1.31 3.09 type 1.31 3.09 type 0.87 4.51 type Overall U value = 1.8 W/m2.k Overall U value = 1.8 W/m2.k Overall U value = 1.8 W/m2.k

Case04 Case05 Case06

INSIDE INSIDE

INSIDE

OUTSIDE OUTSIDE OUTSIDE

spacing spacing

side Out In side Out In side Out In

Sgl LoE (e2=.4) Clr 3mm dim (mm) 30 100 15 70 20 6mm double glazing 6mm dim (mm) 30 200 30 200 20 6mm double glazing 6mm dim (mm) 30 150 26 100 20 materials* CP HB INSU HB CP materials* CP HB AG HB CP materials* CP HB INSU HB CP Wall U value Galzing U value Glazing Wall U value Galzing U value Glazing Wall U value Galzing U value Glazing 0.87 4.51 type 0.87 4.51 type 0.87 4.51 type Overall U value = 1.8 W/m2.k Overall U value = 1.8 W/m2.k Overall U value = 1.8 W/m2.k

Case08 Case09

Case07 INSIDE

INSIDE

INSIDE OUTSIDE

OUTSIDE OUTSIDE

side Out In side Out In side Out In dim (mm) 70 200 28 100 20 Sgl LoE (e2=.4) Clr 3mm dim (mm) 70 200 30 20 Sgl LoE (e2=.4) Clr 3mm dim (mm) 20 200 30 20 Sgl LoE (e2=.4) Clr 3mm materials* NS PC INSU HB CP materials* NS PC INSU HB CP materials* CP SB INSU HB CP Wall U value Galzing U value Glazing Wall U value Galzing U value Glazing Wall U value Galzing U value Glazing 1.66 1.97 type 1.6 2.67 type 0.46 5.8 type Overall U value = 1.8 W/m2.k Overall U value = 1.8 W/m2.k Overall U value = 1.8 W/m2.k

Case10 Case11 Case12

INSIDE

OUTSIDE INSIDE

OUTSIDE OUTSIDE

side Out In side Out In side Out In 6mm Single Glazing dim (mm) 70 150 50 100 20 dim (mm) 70 150 56 100 20 3mm tribleGlazing 6mm dim (mm) 30 150 67 100 20 materials* NS PC AG HB CP 6mm double glazing 16mm ɛ4 materials* NS PC AG HB CP materials* CP HB INSU HB CP *used materials and their thermal properties are shown in Table (4.2).

Table (4.2 ): Thermal properties of the examined walls Thermal properties symbol materials Density (kg/m3) Specific Heat (J/kg-k) Conductivity (w/m.k)

AG Air Gap 1000 1000 0.28 CP Cement Plaster 2000 1000 1.2 HB Hollow Block 1400 1000 0.9 INSU Thermal Insulation 15 1400 0.04 NS Natural Stone 2250 1000 1.7 PC Plain Concrete 2300 1000 1.75 SB Solid Block 1600 1000 1 Source: (PEC, 2004) It is worth to mention that using different types of material for the envelope components but they have the same value of the overall thermal transmittance, gives the same results. This confirms the validity of the study. Asdrubali, D’Alessandro, Baldinelli, and Bianchi (2014) stated that having the same value of thermal transmittance of envelope elements means that they have as same as the ability to resist heat transfer at a certain thickness Therefore, they have total loads would be approximately the same. Results and disccusion: It is noticed that there was a drop in the annual loads (AL) of the examined zones. Inherently, whether in the northern zones or in the southern zone, AL increased wherever we go up across the floors. Overall U-value of RC was 3.37 w/m2.k. The effect of U-value of 1.8 w/m2.k was differed according to the zone direction. Whenever the zone faces the direction of south-southwest such as NW and SW, the effect was less. This is because that the zones of NW and SW are the most zones are exposed to the sun. As shown in Figure (4.1), in case of NE, AL dropped about 11-11.30 % in the L1, L2, L4, and L6. But, AL of L8 was less dropped which was about 8.4%. In case of NW, AL dropped about 8.50-8.70 % in the L1, L2, L4 and L6. But, L8 was dropped less, which was about 6.6%. As shown in Figure (4.2), in case of SE, AL dropped about 11.60-11.65 % in the L1, L2, L4 and L6. But, L8 was dropped less ,which was 9.30%. In case of SW, AL dropped 9.9 % in the L1, L6, while the worth was in L2 about 16.29 %. but, L4 was 10.22 %. L8 was dropped less ,which was 8.20%. So, it is suggested to achieve NZE of QEAB, to minimize the overall U-value for the envelope components. The result reached here is similar to what Evola and Margani (2014)

found when they investigated the energy performance of the Italian residential multi- storey buildings (as the Mediterranean climate zone) towards NZEB. U-values of the envelope components were ranged between 1.53-4.09 W/m2. k before retrofit. They were ranged between 0.31-0.4 W/m2. k after the retrofit. The energy savings was about 46%. L01 NE L01 NW L02 NE L02 NW L04 NE L04 NW L06 NE L06 NW L08 NE L08 NW 12.00

8.00

MWH 4.00

0.00 REF

C A S E 0 7 C A S E 0 1 C A S E 0 2 C A S E 0 3 C A S E 0 4 C A S E 0 5 C A S E 0 6 C A S E 0 8 C A S E 0 9 C A S E 1 0 C A S E 1 1 C A S E 1 2

Figure (4.1): The effect of applying U value constraints on northern apartments

L01 SE L01 SW L02 SE L02 SW L04 SE

L04 SW L06 SE L06 SW L08 SE L08 SW 12.00

8.00

MWH 4.00

0.00

REF

A S E 0 1

C A S E 0 2 C A S E 0 3 C A S E 0 4 C A S E 0 5 C A S E 0 6 C A S E 0 7 C A S E 0 8 C A S E 0 9 C A S E 1 0 C A S E 1 1 C A S E 1 2 Figure (4.2): The effect of applying U value constraints on southern apartments

It is beneficial to adopt using U value restrictions to minimize the loads that are used in cooling and heating space in Gaza. It is concluded that an efficient construction element is characterized by very low values of thermal transmittance (Asdrubali et al., 2014), in particular, the elevations face the west and south directions. Currently, for thermal comfort in the buildings, energetic studies use climber plants that do not need for extra distance to grow in hot climate zones. Also, in case of the process of retrofit, upper floor needs for additional measures such as pergolas or green roof to veil the extra heat from the sun. So, this study strongly recommends for NZER in Gaza to couple the use of energy measures with the thermal comfort criteria that do not need for extra distance. In the next measures, case 06 was elected due to having the lowest U-value of the wall. Also, it is the more reasonable and realistic case because of its

appropriate cost (Ayyad & Fekry, 2016) and weight on construction. Taking into account that others were depending on stone or solid hollow concrete that have extra weight, therefore, barring loads on the structure. For that, the following procedures were carried out by using case 06 as a RC.

4.1.2 Shading devices SHDs and Shading coefficient SC Shading devices are commonly used in Gaza due to its capability to reduce the solar incident radiation that entered into space. Although the outdoor high temperature in summer cannot be tolerated, this procedure looks like an alternative solution in case of electricity cutting which sometimes reaches to more than twelve hours. The common pattern of shading device is an external tent canopy which is made up of waterproof fiber sunshade as shown in Figure (4.3). The inside one is usually textile dress curtain. At first, the researcher examined the total heating and cooling load of the southern side of the building using MXM. This was especially in the southwestern zones of the first floor, fourth floor, and last floor respectively by using different types of SHDs. These types were limited to four types: blinds (BLs), overhangs (OHs), louvers (LOs), side fins (SFs) and combinations of more than one type. RC of the envelope was case 06, as shown in Table (4.1), their AL were 6.23, 7.07, and 8.39 MWh for L1-SW, L4-SW, and L8-SW respectively.

a) Examples of fixed shading (from the left horizontal sunscreen, fixed overhang, grating and sunscreen, fixed blades) b) Examples of roller blinds

c) Mobile shading (from the left Persian shutters, roller blinds, and Venetian blinds) d) Curtains (left drop-arm awning, right tent canopy)

e) Examples of internal blinds (from the left classic drapes, roller drapes, Venetian blinds, and vertical curtain) f ) Integrated screens (from the left Venetian blind and roller blind) Figure (4.3): Types of shading devices

Source: (Cellai, Carletti, Sciurpi, & Secchi, 2014)

4.1.2.1 Blinds (BLs) Blinds were examined on inside and outside of the windows. It should be taken into consideration that BLs should be made up of low reflective material i.e. aluminum. The results showed that there were fluctuations of values of cooling and heating loads occurred. Wherever the BLs were located inside the windows, total loads (AL) increased. This was happened due to the increase of heating loads (AHL) by 280 kWh and 687 kWh for cooling (ACL) in the L01-SW zone. ACL increased about 13.43%. The effect of this step differed when the zone L04-SW was tested. AL was 7.01 MWh which increased about 0.86%. AL of zone L08-SW was 9.22 MWh which increased about 9%. One can notice that AHL increasingly took place wherever the BLs located inside the windows especially in the lower and upper floors, as shown in Figure (4.4). On the other hands, located outside the windows, BLs have given another impression. Even though AHL increased, ACL inclined. AHL of zone L01-NW increased about 50%. While ACL decreased about 25.32%. AL decreased about 6.28%. By zone L04- SW, AHL increased about 71.79%, while ACL minimized about 37.51%. AL was decreased about 26.26%. As for zone L08-SW, AHL increased about 48.37%, while ACL decreased about 21.63%. AL decreased about 7.8%. 10.00

5.00 MWh 0.00 AHL ACL AL AHL ACL AL AHL ACL AL L01-SW L04-SW L08-SW

RC IN-BLs OUT-BLs Figure (4.4): The effect of applying blinds on the AL of L1-SW, L2-SW, and L8-SW

Discussion: In case SHDs devices were blinds controlled manually and they were assumed to be closed all the time, the results showed that BLs located inside the windows behaved as insulation layer which prevented indoor ambient to penetrate to outside i.e. because of the horizontal slats, it is difficult to control heat loss through interior window blinds (Molina Larraín, 2014). As a result, AL increased by about 21.07, and 16.18% in zones L1-SW, and L8-SW respectively. In contrast, Kang, Kang, and Song (2015) proposed a cooperative controller (automated system) that was coupled with heating, cooling, lighting and blind control system. As a result, cooling load minimized about 40%, therefore, it achieved energy saving about 28%. On the other hand, blinds installed out of the windows made the temperature at the interior surface of the window close to that of the indoor air. Then, AL decreased about 6-7.8%. While Wang, Du, Zhang, and Xu (2017) found when using the external blinds with low-E double glazing, AL reduced about 46.9%. Also, when they used the same blinds with triple glazing system, AL inclined about 56.4%. Consequently, using the blinds inside the windows is a strategy that should be compatible with an automation system such as dynamic windows (see category 2.5.3). This system is able to control the amount of SHG that get into space by using sensors. But, in case the blinds are outside the windows, the energy saving will be more effective when using double or triple glazing systems. As a mean for shading, the study is going to recommend to connect the blinds with automation systems in order to get a glazing system with very low SHGC (Mitterer, Künzel, Herkel, & Holm, 2012).

4.1.2.2 Overhangs (OHs) The overhangs are horizontal elements that are projected from the walls. They are located above the windows externally. It should be taken into consideration that OHs should be made up of low reflective material i.e. aluminum. Three dimensions have the ability to improve the performance of the overhangs. They are available in DB. These dimensions are: projection depth, vertical offset from the top of the window, and horizontal window overlap, as shown in Figure (4.5). In this category, horizontal window overlaps and vertical offset from the top of the window were treated as a constant value at 30cm. Unless the distance of setback in Gaza is enough in some

cases, QEAB has a chance to implement overhangs outside the windows. Two options were implemented: 0.5m and 1m. Obviously, wherever the projection of overhang was increased, the annual load (AL) was minimized. This was happened due to its ability to reduce the exposed area to the sun of whether the windows or the walls. As shown in Figure (4.6), the annual heating loads (AHL) increased by about 29.57, 16.29, and 21.19% in zones L1-SW, L4-SW, and L8-SW when the overhang projection depth was 0.5. While it increased by about 37.69, 44.18, and 31.77 when the overhang projection depth was 1m. In turn, the annual cooling load (ACL) declined by about 9.95, 17.37, and 6.69 in zones L1-SW, L4-SW, and L8-SW, when the overhang projection depth was 0.5m. When the overhang projection depth was 1m, ACL declined about 16.01, 24.76, and 12.34% in the same zones. In spite of that AHL increased, ACL and either did AL declined in the l04-SW rather than the lower floor as L01-SW and upper floor such as L08-SW.

Figure (4.5): Dimensions of overhang

10.00

5.00 MWh 0.00 AHL ACL AL AHL ACL AL AHL ACL AL

L01-SW L04-SW L08-SW

RC 0.5 OHs 1OHs

Figure (4.6): The effect of applying OHs on AL of L1-SW, L2-SW, and L8-SW

Discussion: In case SHDs were OHs with projection of 0.5 m and 1m, ACL decreased about 29.57-37.69 % for zone L1-SW. Also, they decreased ACL about 16.29-44.18% for zone L4-SW. Moreover, they can decrease ACL about 21.19-31.77% for zone L8-SW. However, He and Ng (2017) stated that OH helps to reduce ACL but it is not helpful

in reducing AHL. When there are some nearby buildings surrounding the examined buildings, the biggest reduction of cooling demanded is only about 2.8% (high rise suburban). In order to build up the energy model in DB, The canyon space of adjacent buildings was hypothetically determined. In case of QEAB, the impressive effect was on L4-SW annual loads in contrast to L1-SW and L8-SW. As for L1-SW, AL affected by open ground floor (rare hall), in addition, there is no plantation in this side. These can increase the air velocity in the first floor. It is known that the lower range of internal air velocity is preferred for thermal comfort. While L8-SW is the more zone that exposed to the sun. However, in case the OHs are permanent elements, they reduce the annual cooling loads in the summer, in contrary, they increase the annual heating loads in winter. Consequently, this encourages the designers to find kinetic overhangs that can be adapting to the surrounding ambient. This is because that the direct sun beam in summer should be avoided, but in the winter, the sun is a desirable element that can help in reducing the AHL. So, this study recommends for NZEBs to implement operable OHs. It is worth to mention that Handbook-Fundamentals (2001) has defined an indicator of shade line factors (SLFs) of the overhang according to latitude degree, as shown in Table (4.3). Gaza location is in the latitude of 32ᵒ N approximately. So, it defines the shading length (SL) below the OH, which equals

SLF times the overhang width (OHw), as shown in Equation (4.2): 푆퐿 = 푆퐿퐹 푥 푂퐻푤 …………………………………………………………………... EQ (4.2)

In case of the overhang of 0.5m and 1m projection depth, shading length in southwestern elevation is (1.6*0.5) and (1.6*1) respectively. Shading length is 0.8m when the overhang projection depth is 0.5m, while shading length is 1.6m when the overhang projection depth is 1m. This can bring us to a quick notion of the overhangs mechanism that their shading areas must cover more than half of the window areas. Table (4.3): Shade line factor (SLFs)

Source: (Handbook-Fundamentals, 2001)

Figure (4.7): Dimensions of sidefins

4.1.2.3 Sidefins (SFs) Another type of SHDs were applied to the windows of the QEAB. They were sidefins (SF). Looking at Figure (4.7), SFs are the projected vertical elements located beside the outside right and left edges of the window. Here, the combination of OHs and SFs were applied to the windows of zone L1-SW, L4-SW, and L8-SW. This combination looked like a box in order to block solar radiation get into space whether from above or sides of the windows. Two main dimensions found in DB were determined SFs which are projection depth and horizontal offset from the right and left edges of the window, in addition to the found major dimensions of OHs. Meanwhile, OHs dimensions were mentioned before in category 4.1.2.2. The horizontal offset from window whether on left or right was fixed at 30 cm. The variable was the depth of projection. They were limited in two values: 50 and 80 cm. Referring to Figure (4.8), by applying the combination of OHs and SFs at 50cm, ACL decreased about 11.05, 18.75 and 7.80% in the zones L1-SW, L4-SW and L8-SW respectively. On the other hands, AHL increased about 31.1%, 22.16 and 23.05% in the zone of L1-SW, L4-SW and L08-SW respectively. AL of the L1-SW zone decreased about 2.55, 16.93, and 3.27%. AL

L08-SW AHL

ACL L04-SW AL

L01-SW AHL 0.00 2.00 4.00 6.00 8.00 10.00 MWh 0.8 SF+OH 0.5 SF+OH RC Figure (4.8): The effect of applying a combination of OHs and SFs on ALs of L1-SW, L2- SW, and L8-SW

Whereas the case of 80 cm projection for the same combination, ACL decreased about 16.22%, 24.95 and 15.52% in the zones L1-SW, L4-SW and L08-SW respectively. On the other hands, AHL increased about 36.99%, 41.96 and 30.70% in the zone of L1-SW, L4-SW and L08-SW respectively. AL decreased about 4.89, 21.20, and 5.70 in the zones L1-SW, L4-SW, and L8-SW respectively. Discussion: Using combinations of OHs and SFs (0.5, and 0.8 cm) reduced ACL about 31.10- 36.99% for zone L1-SW. AL of zone L4-SW decreased about 22.16-41.96%. As for L8-SW, it reduced about 30.70-37.84%. This agrees with Ashjaee, Faizi, Seraj, and Zarouri (2015) who found that SFs can decrease ACL about 23.45%. Idchabani, El Ganaoui, and Sick (2017) provided an analysis study for exterior shading by overhangs and fins in hot climate. They used projection factors of OHs and SFs. If 0.5 and 1m OHs were facing SW direction, ACL decreased about 15.8-22.00%. If projection factor was 60%, ACL would decrease about 7.4 in case of SFs, and 27.4% in case of OHs. However, when SHDs are a combination of overhangs and sidefins that means that their forms would be close to the box. This reduced the AL rather than using overhang or sidefins alone. For that, this combination prevents sunbeam to enter into space from both of the top and the sides of the windows. To control the design of this combination, it is helpful to use the projection factors. But this can increase the annual heating loads. So, the study going to adopt using operable SHDs that designers can use their projection factors to cut down sunbeam inter into space.

4.1.2.4 Louvers (LOs) Fourthly, another type of SHDs was applied to the selected zones in QEAB. They were louvers which were located outside the windows. It should be taken into consideration that louvers should be made up of low reflective material i.e. aluminum. Louvers were usually defined by their dimensions in DB, as shown in Figure (4.9). These dimensions are vertical offset from the top of the window, vertical spacing, blade depth, the angle of louvers’ blades, distance from the window, and horizontal window overlap. All dimensions were assumed a constant value except the angle of louvers’ blades. Vertical offset from the top of the window was considered that the louvers were not flush with the window top, it was 10cm. vertical spacing was 20cm,

a number of blades were 7. Blades depth were 20cm. horizontal window overlap was 30cm. The only variable dimension was the angle of lovers’ blades which were assumed to be 10ᵒ, 30ᵒ, 40ᵒ, and 60ᵒ. This step was applied to the L01-SW, L04-SW, and L08-SW zones.

Figure (4.9): Dimensions of louvers

Referring to Figure (4.10), the results were given an impression that was looked like what was given in the case of OH. ACL decreased. In turn, AHL increased. The possibility of applying the blade angle of 10ᵒ decreased ACL about 16.85, 26.00, and 13.16% in the zones L1-SW, L4-SW and L8-SW respectively. AHL increased by about 43.58, 60.42, and 39.95% in the zones of L1-SW, L4-SW and L8-SW respectively. AL decreased by about 2.6, 19.15, and 3.6% in the zones L1-SW, L4- SW, and L8-SW respectively. We would notice the same changing impression when using the other angles of blades. Wherever the angles values were changed increasingly, the percentage of the impact of these changed were increased. Therefore, the possibility of applying the blade angle of 30ᵒ decreased ACL about 19.17, 28.87 and 15.31% in the zones L1-SW, L4-SW and L08-SW respectively. On the other hands, AHL increased about 46.90, 66.35, and 44.09% in the zone of L1-SW, L4-SW and L8-SW respectively.

8.00 6.00 4.00

MWh 2.00 0.00 AHL ACL AL AHL ACL AL AHL ACL AL L01-SW L04-SW L08-SW

RC LOs 10ᵒ LOs 30ᵒ LOs 40ᵒ LOs 60ᵒ

Figure (4.10): The effect of applying LOs on ALs of L1-SW, L2-SW, and L8-SW

AL decreased about 2.91, 20.16, and 4.01% in the same zones. When applying the blade angle of 40ᵒ, ACL decreased about 19.83, 30.50, and 15.91% in the zones L1- SW, L4-SW and L8-SW respectively. AHL increased about 47.63, 68.55, and 44.98% in the same zones respectively. Also, AL inclined about 3.07, 20.93, and 4.19%. Finally, the impact of applying the blade angle of 60ᵒ, ACL decreased about 20.51, 25.17 and 16.55% in the zones L1-SW, L4-SW and L8-SW respectively. AHL increased about 48.30, 70.63, and 45.73% in the zone of L01-SW, L4-SW and L08- SW respectively. AL decreased of the L01-SW zone about 3.27, 15.05, and 4.45%. Discussion: In case the SHDs were LOs (10, 30, 40, 60ᵒ), ACL decreased about 43.58-48.30% for L1-SW. It reduced about 60.42-70.36 for zone L4-SW. ACL decreased about 39.95-45.73% for zone L8-SW. Ashjaee et al. (2015) found that LOs can decrease ACL about 24.29%. Altitude angle plays a significant role in designing the louvers as horizontal elements. The study found that all angle of blades achieved decreasing annual cooling loads. As for L4-SW, 40 achieved more energy savings. More than 40 degree, shading system become close. The function of louvers is to prevent SHG to get into the space, although, they effect on visual comfort. Currently, the louvers take many architectural forms that they can be sensitive to light and glare by using smart materials connected to sun-tracking software. Also, it can be used as operable louvers that can response to the amount of the light required for each space and move around the perimeter of buildings. In case of QEAB, louvers can reduce ACL, but they were not helpful to reduce the annual heating loads. This study recommends for NZEBs to use sun tracking system fundamentally in the study of horizontal SHDs in order to achieve the desirable thermal comfort.

4.1.2.5 Combinations of OHs, SFs, and LOs Fifthly, several combinations of OH, SFs and LOs were examined in the same zones of L1-SW, L4-SW, and L8-SW. These combinations were demonstrated by the vertical offset from the top of the window and the projection depth. The number of LO blads were 3. As shown in Figure (4.11), these blades were fixed at 20 cm depth with angle of 60ᵒ. The vertical offset from the top of the window was assumed to be flush with the top of windows or to be 70cm.

Figure (4.11): The combination of OHs, SFs, and LOs, type (1)

It looked like the traditional notion of shading device which depended on installing wooden elements as boxes outside the windows. It was called mashrabiyya. Starting with the combination of 50cm depth of projection OHs with the vertical offset from the top of the window was assumed to be flush with the top of windows (0.5OH0). In addition, sidefins were implemented with 0.5 depth of projection. This combination decreased ACL by about 18.70, 28.00 and 14.88% in zones L1-SW, L4- SW and L08-SW respectively. AHL increased about 42.10, 56.58 and 37.84% in zones L1-SW, L4-SW, and L08-SW respectively. AL decreased about 4.87, 21.91, and 5.80% in the same zones. While the combination of 80 cm depth of projection with overhang vertical offset from the top of the window was assumed to be flush with the top of windows ( 0.8OH0). SFs were installed with the 80cm depth of projection. As shown in Figure (4.12), the results showed that ACL decreased about 19.51, 22.03, and 15.56% in zones L1-SW, L4-SW and L08-SW respectively. AHL increased about 42.67, 58.05% and 38.47% in the zone of L1-SW, L4-SW and L08-SW respectively. Also, AL decreased about 5.30, 15.58, and 6.19 %. In case of the combination of 80 cm depth of projection, the overhang vertical offset from the top of the window was assumed to be 70cm (0.8OH70), in addition to sidefins. The results looked like the previous combination with the slight difference. This combination decreased ACL about 18.73, 27.95 and 14.80% in zones L1-SW, L4-SW and L08-SW respectively. AHL increased about 41, 53.10, and 36.27% in zones L1-SW, L4-SW and L08-SW respectively. AL decreased about 5.38, 22.50, and 6.19%. However, other types of combinations were implanted as well as the previous combinations, but here the variable was the number of louvers’ blades which were 6, as shown in Figure (4.13). They were 0.5TYP2, and 0.8TYP2. Annually, the results showed a slight difference

between both of the combination of (0.5TYP2) and a combination of (0.8TYP2), as shown in Figure (4.14). For instance, the combination (0.5TYP2) has decreased ACL about 25.8, 36.90 and 21.31% in the zones L1-SW, L-SW and L8-SW respectively. AHL increased about 51.66, 73.32, and 49.83% in the same zones. Annually, AL of the L01-SW zone decreased about 5.73%, a load of the L04-SW zone decreased about 24.89%, and the load of the L08-SW zone decreased about 6.84%.

10.00 5.00 Mwh 0.00 AHL ACL AL AHL ACL AL AHL ACL AL L01-SW L04-SW L08-SW

RC 0.5OH0 0.8OH0 0.8OH70

Figure (4.12): The effect of applying the combination of OHs, SFs, and LOs (type (1)) on ALs of L1-SW, L2-SW, and L8-SW

Figure (4.13): The combination of OHs, SFs, and LOs, type (2)

8.00

3.00 MWh -2.00 AHL ACL AL AHL ACL AL AHL ACL AL L01-SW L04-SW L08-SW RC 0.5TYP2 0.8TYP2

Figure (4.14): The effect of applying the combination of OHs, SFs, and LOs (type (2)) on AL of L1-SW, L2-SW, and L8-SW

Discussion: The combination of OHs, SFs, and LOs gives an effective mechanism to prevent solar heat gain to enter into the zones. So, using this combination is recommended in this study especially in the southern zones. However, the enclosure shape may take many forms such as boxes with shutters, egg-crate louvers...etc. Chua and Chou (2010)

have found that the half egg-crate louver was the most suitable SHDs for residential buildings facing the south orientation in hot climate. But, the issue of increasing the AHLs in a case of using cubic form of shading devices make the designers to invent many forms of shading devices. For example, they found kinetic and folded shading device that can be removed in winter. So, in order to get NZEB, external shading devices such as overhangs, and louvers, should be encouraged as architectural elements to protect building envelopes from solar radiation. So, significantly they will improve the internal thermal comfort conditions (Al-Tamimi & Fadzil, 2011).

4.1.2.6 Shading coefficient (SC) ASHRAE fundamental handbook 2001 chapter 7 has defined shading coefficient in order to calculate the heat gain through fenestration system whether for glazing or for shading devices. SC of glazing is the ratio of F for the suggested glazing system to F of a standard reference glazing of single-pane (McCluney, 1991), Where F is called the solar heat gain coefficient (SHGC), as shown in Equation (4.3): 푠표푙푎푟 ℎ푒푎푡 푔푎𝑖푛 푐표푒푓푓𝑖푐𝑖푒푛푡 표푓 푎푛푦 푔푙푎푠푠 푠푐 = ………………………………..…EQ (4.3) 푠표푙푎푟 ℎ푒푎푡 푔푎𝑖푛 푐표푒푓푓𝑖푐𝑖푒푛푡 표푓 푟푒푓푒푟푎푐푛푒 푔푙푎푧𝑖푛푔

In general, effective shading coefficient (SC) of any fenestration system can be obtained by multiplying the shading coefficient of glass (SCg) and the shading coefficient of sun shading devices (SCf), as shown in Equation (4.4): 푆퐶 = 푆퐶푔 푥 푆퐶푓…………………………………………………………………...…EQ (4.4)

It is worth to mention that SC value is ranged between 0 and 1. Whenever the SC value is close to 1 that means the glazing or fenestration system is fully exposed to the Sun. whenever it is close to 0 that means the fenestration system is fully shaded. To recognize the appropriate solution of SHDs for the QEAB as a step toward obtaining NZEB, the researcher sought about the possibility to define the desired SC that could prevent the energy consumption. In the beginning, natural ventilation was chosen. The intended floor was the fifth floor with its symmetric zones of NW, NE, SE, and SW. The number of windows was five, W01, W02, W03, W04, and W05, as shown in Figure (4.15). The window patterns were classified into two groups according to their width. W01, W02, and W05 had 2.8m width. W03 and W04 had 1.8m width. SHDs were limited in two depths of projection: 30 and 50 cm taking into consideration the

lake of the distance of setback between buildings in Gaza. Overhang (OH) and the combination of overhang and sidefins (OH+SF) were chosen. The type of the envelope structure was chosen to be case 06 whose specifications are found in Table (4.1).

Figure (4.15): Positions of the typical windows patterns

Primarily, shading coefficient was calculated hourly from the sunrise until sunset. Hourly SC of shading devices was calculated regarding Equation (4.5). For a whole day, the hourly solar heat gain shall be computed and summed up to 12 daylight hours. The total solar heat gain is divided by the sum of the radiation (Building & Construction Authority-Singabor, 2004).

ℎ=12 ∑ℎ=1 (퐴푒 푥 퐼퐷+퐴 푥 퐼푑) SC= ℎ=12 …………………………………………………………....…EQ (4.5) ∑ℎ=1 (퐴 푥 퐼푇)

Ae: exposed area of the window. A: height of the window. AS: shaded area of the window. ID: direct radiation. Id: diffused radiation. I: total radiation. To calculate the effective SC of shading devices, the calculations should be carried out theoretically for 12 months of the year. To facilitate this process, four months were selected. These representative months were March, June, September, and December, according to Equation (4.6). Definitely, they were March 21, June 22, September 23, and December 22.

∑ (퐺 푥 퐼 +퐼 )+ ∑ (퐺 푥 퐼 +퐼 )+ ∑ (퐺 푥 퐼 +퐼 )+ ∑ (퐺 푥 퐼 +퐼 ) 푒푓푓푒푐푡푖푣푒 푆퐶 = 푀 퐷 푑 퐽 퐷 푑 푆 퐷 푑 퐷 퐷 푑 ……….EQ (4.6) ∑푀 퐼푇+ ∑퐽 퐼푇+ ∑푆 퐼푇+ ∑퐷 퐼푇

푃 Where G= Ae/A = 1 − (cos ∅ tan 휃 + sin ∅ the fraction of area exposed to direct 퐴 solar radiation, θ is solar altitude, ∅ is projection angle. P is projection depth.

Direct radiation (ID) and diffused radiation Id were obtained by using DesignBuilder V5. Also, solar altitude was defined throughout the day. SC of glass was calculated by

using Equation (4.3). Solar heat gain coefficient (SHGC) whether of any glass or of reference glass was defined by DesignBuilder V5 which is solar Trans plus solar gain. Equation (4.4) was used to obtain SC of the used fenestration. As shown in Table (appx 1.2), the results showed rapprochement values between the patterns of windows in the same zone. When SHDs were overhangs, SC of fenestration was near to 1. When SHDs were the combination of overhangs and sidefins, SC of fenestration was near to 0. In spite of their location into the northern elevation in the zones L05-NE and L05- NW, W04 and W05 have recorded high SC of fenestration due to their areas and low solar attribute angle, as shown in Figure (4.16). Vice versa, although it is located into the southern elevations in the zone L05-SE and L05-SW, W03 and W04 have recorded low SC of fenestration due to their low areas and high solar attribute angle. These results led the researcher to classify the SC values of fenestration into five categories (as shown in appendix (01), Table (appx 1.2)) in order to integrate them into the calculations of ventilation using the main types 0f HVAC: natural, mechanical, and mixed-mode ventilation. These categories were arranged descendingly. Where 1 means that the fenestration is fully exposed to the sun, 0 or near to means that the fenestration is fully shaded or partially shaded. Natural ventilation was established to integrate with the variable air volume (VAV) system to provide cooling to the examined zones. Mechanical and mixed ventilations were separately installed using also VAV system. VAV was demonstrated by setpoint temperature at 27ᵒC for cooling and at 19ᵒC for heating. Setback setpoint temperature was at 31ᵒC for cooling and at 12ᵒC for heating in order to manage energy consumption.

0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0

LOCAL…

0.5 OH 0.5 0.5 OH 0.5 OH 0.3 OH 0.5 OH 0.3 OH 0.3 OH 0.5

0.3 OH 0.3

0.3 SF+OH 0.3 SF+OH 0.5 SF+OH 0.3 SF+OH 0.5 SF+OH 0.3 SF+OH 0.5 SF+OH 0.3 SF+OH 0.5 L05 NE L05 NW L05 SE L05 SW W1 W2 W3 W4 W5 Figure (4.16): Shading coefficient of examined fenestration

In fact, some buildings require a low level of cooling during unoccupied periods to prevent the building becoming too hot and to reduce the startup cooling load the next morning. Enter the setpoint temperature to be used at night-time, weekends and other holidays during the cooling season (DesignBuilder 2, 2009; DesignBuilder V5). Even though our case assumption was to be full occupancy, setback setpoint management has been done at night-time. Taking into consideration that the value of 1 is excluded because it means that there were no shading devices installed. So, let’s start with natural ventilation and using cooling assistance, referring to Figure (4.17), the results showed whenever the SC values are less than (0.6-0.7), cooling loads of zones of the fifth floor (NE, NW, SE, and SW) would be less. Whenever the values become more than (0.6-0.7), cooling loads in one zone would be more. The majority values of (0.6-0.7) can be achieved when using 30 cm OH or 30 cm combination of OH and SFs, as shown in Table (appx 1.2) and Figure (4.16).

NE NATURAL NAT+cooling NW NATURAL NAT+cooling SE NATURAL NAT+cooling SW NATURAL NAT+cooling

8.00

MWH

5.00 1 0 . 8 - 0 . 7 0 . 7 - 0 . 6 0 . 6 - 0 . 5 0 . 5 - 0 . 4 Figure (4.17): The effect of examined SCs of fenestration on cooling loads and natural ventilation

Whenever the values have been achieved less than (0.5-0.6), the SC becomes more effective due to its effect on loads declined. It worth to mention that loads have declined simultaneously in the four zones until they met on the values of (0.4-0.5) whether on northern zones (NE and NW) or southern zones (SE and SW). Starting with NE zone, it has achieved fewer loads, then NW zone followed, then SE and SW. This refers to the fact that zones facing to the south and west direction are the most zones exposing to the sun. Secondly, using mechanical ventilation, almost parallel effects have happened on heating and cooling loads of zones of the fifth floor (NE, NW, SE, and SW), referring

to Figure (4.18). The results showed whenever the shading coefficient values are less than (0.8-0.7) until they reached to (0.7-0.6), the heating and cooling loads of zones of fifth floor (NE, NW, SE, and SW) would be less. Then, the loads declined until the values of SC become near to (0.5-0.6). For that, (0.5-0.6) values becomes as a turning point of shading devices designing options. Then, the oscillatory loads have occurred. Cooling loads and heating loads ascendantly increased. This effect has faded away when the zones become facing south direction i.e. SE, and SW zones as shown in Figure (4.18). The values of (0.5-0.6) can be achieved when using 50cm OHs, as shown in Table (appx 1.2) and Figure (4.16). Also, whenever the values that have been achieved are (0.5-0.6), SC become more effective due to its effect on loads declined.

NE MechVent ACL NE MechVent AHL NW MechVent ACL NW MechVent AHL SE MechVent ACL SE MechVent AHL SW MechVent ACL SW MechVent AHL 30.00 25.00 20.00

15.00 MWH 10.00 5.00 0.00 1 0 . 8 - 0 . 7 0 . 7 - 0 . 6 0 . 6 - 0 . 5 0 . 5 - 0 . 4

Figure (4.18): The effect of examined SCs of fenestration on mechanical ventilation loads.

Lastly, using mixed-mode ventilation. Mixed mode is a HVAC system whom temperature control for either cooling or heating is restricted between the minimum and the maximum outdoor temperatures. When the outside air temperature falls below the minimum value or goes above the maximum value, the openings are closed and the HVAC system operates (DesignBuilder 2, 2009; DesignBuilder V5). A steady effect has approximately happened when the achieving values were between (0.8-0.7) and (0.7-0.6) of shading coefficient. Then, the loads have declined until they reached the values of (0.6-0.5). Then we can notice that cooling loads declined and heating loads went up as a result of being windows approximately fully shaded. This note was in all zones of the fifth floor (NE, NW, SE, and SW), referring to Figure (4.19). We found that cooling loads and heating loads for SC values of (0.5-0.6) become another

time as a turning points of shading devices designing option. These values of (0.5-0.6) can be achieved when using 50cm OH, as shown in Table (appx 1.2) and Figure (4.16). However, in case of mechanical and mixed mode ventilation, the annual loads have increasingly been raised wherever our direction that it looks like a mirrored capital letter of N, i.e. ascendingly, NE, NW, SE, and SW. As mentioned before, the results showed that values of SC between (0.6-0.5) achieved fewer loads whether of cooling loads or heating loads. This was resulted by using 50cm OH.

NE MXM ACL NE MXM ACL NW MXM ACL NW MXM AHL SE MXM ACL SE MXM AHL SW MXM ACL SW MXM AHL

20.00

MWH 10.00

0.00 1 0 . 8 - 0 . 7 0 . 7 - 0 . 6 0 . 6 - 0 . 5 0 . 5 - 0 . 4

Figure (4.19): The effect of examined SCs of fenestration on mixed mode ventilation loads

But, the question here: Can we get the shading coefficient between (0.6-0.5) by another type of shading devices? For that, the researcher used a software of Windows 7.5 (v7.5.15) in order to examine SC of (0.6-0.5) with other types of SHDs. This is to enable designers to use more options of SHDs. The software was created by Lawrence Berkeley National Laboratory (LBNL) for windows & daylighting software. Berkeley Lab WINDOW was invented for analysis and modeling NFRC glazing system. It is available in https://windows.lbl.gov/software/window/window.html. NFRC is The National Fenestration Rating Council which is a non-profit organization that establishes objective window, door, and skylight energy performance ratings to help designers compare products and make informed purchase decisions. The application enables designers to define which type of fenestration can be used to get certain specifications. Our case was about SC. The process took place using our suggestion of glazing systems in the previous energy measure of U-value, as shown in Table (4.4). Their specifications are found in Table (4.1).

100

Table (4.4): The examined glazing types Case01: 6mm double glazing 16mm spacing Case02: Dbl LoE (e3=.1) Clr 3mm/6mm Air Case03: Dbl Clr 3mm/13mm Air Case 04: 6mm double glazing 6mm spacing Case 06: Sgl LoE (e2=.4) Clr 3mm Case 10: 6mm double glazing 16mm ɛ4 Case 11: 3mm triple Glazing 6mm Case 12: 6mm Single Glazing

Our target was to get SC between (0.6-0.5) using products that available in the software of Window 07. The selected products were limited in ID numbers of 3001, 22005, and 3002 for shutter blinds. These products that are blinds were located outside of window regarding our results in category 4.1.2.1. Moreover, ID numbers of 22501, and 22502 for perforated shading devices were chosen, as shown in Table (4.5). The former ones were used due to their common using in Gaza. But, the latter ones were examined due to their appearance that looks like the Mashrabiyya in our traditional buildings. The results showed that the intended SC values of (0.6-0.5) were achieved by using the following cases, as shown in Figure (4.20):

Table (4.5): The examined shading devices with their ID product numbers via W07

ID product number 3001 22005 3002

BLIND

PREFORATED

ID product number 22501 22502

101

1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1

6mm double 6mm

(e3=.1) Clr (e3=.1)

Glazing

spacing spacing

3mm/6mm Air 3mm/6mm

case02-Dbl LoE case02-Dbl

case03-Dbl Clr case03-Dbl

case06-Sgl LoE case06-Sgl

case11-3mm

3mm/13mm Air 3mm/13mm

(e2=.4) Clr 3mm (e2=.4)

glazing 6mm glazing

glazing 16mm glazing

tribleGlazing 6mm tribleGlazing

glazing 16mm ɛ4 16mm glazing

case12-6mm Single case12-6mm

case01-6mm double case01-6mm double case04-6mm case10

main 3001 3002 22005 22501 22502

Figure (4.20): SC of the examined glazing systems

1. No shading devices with double glazing system with emissivity: Case 10: 6mm double glazing 16mm ɛ4. 2. ID product number of 3001 (shading devices) with the following cases of glazing: Case01: 6mm double glazing 16mm spacing, Case03: Dbl Clr 3mm/13mm Air, Case 04: 6mm double glazing 6mm spacing, Case 11: 3mm triple Glazing 6mm, and Case 12: 6mm Single Glazing. 3. ID product number of 3002 (shading devices) with the following cases of glazing: Case02: Dbl LoE (e3=.1) Clr 3mm/6mm Air, Case 10: 6mm double glazing 16mm ɛ4, and Case 12: 6mm Single Glazing. 4. ID product number of 22005 (shading devices) with the following cases of glazing: Case01: 6mm double glazing 16mm spacing, Case03: Dbl Clr 3mm/13mm Air, Case 04: 6mm double glazing 6mm spacing Case 11: 3mm triple Glazing 6mm, and Case 12: 6mm Single Glazing.

So, instead of using OHs of 50cm, we can get SC values of (0.6-0.5) of fenestrations by using other types of shading devices as well as ID products of 3001, 3002, and 22005 with above mentioned cases of glazing. However, case 06 with all examined shading devices gave low SC. Also, ID product numbers of 22501, and 22502 for perforated shading devices have given low values of SC that can be benefit in case of using natural ventilation, referring to Figure (4.17). For that, the experts of the energy field, as well as ASHRAE, have developed many ways to manage the electricity consumption in the buildings such as SCL and GLF. SCL factor is used for adjusting the transmission of heat gains from the glass. It can be calculated by Equation (4.7):

102

푄 = 퐴 푥 푆퐶 푥 푆퐶푙 ……………………………………………………………….….. EQ (4.7)

Moreover, to calculate sensible heat gain through the glass, ASHRAE found Glass load factor (GLF) which depends on window orientation, type of glass, type of interior shading, and outdoor design temperature. The GLF includes effects of both transmission and solar radiation. Glass shaded by overhangs is treated as north glass. So, the load can be calculated by Equation (4.8): 푞 = (퐺퐿퐹) 퐴……………………………………………… ……………….…….. EQ (4.8) q: Load through the glass in Btu/hr, GLF: Glass load factors, A: area of glass in ft2. This study uses SCL and GLF to estimate the solar transmittance (ST) and sensible heat gain (SHG) through the examined cases of glazing systems that were mentioned before in Table (4.1). So, the next step is to identify the sensible solar heat gain (SHG) through the glass by using GLF. This would be when the SC values were between (0.6- 0.5). Regarding ASHRAE handbook 2001, GLF was defined according to the types of glasses, and their façades directions. Also, the values were corrected regarding the attitude of 32ᵒN. The windows were classified into two groups according to their areas: W01 was 4.2m2, and W02 was 2.7m2. SHG was calculated by Equation (4.8).

1500 1000 500 0 area of area of area of area of area of area of area of area of W01 W02 W01 W02 W01 W02 W01 W02 SINGLE GLASS DOUBLE GLASS Heat-Absorbing Clear Triple Glass Double Glass

NE NW SE SW

Figure (4.21): Sensible heat gain through no shaded glass by using GLF

As shown in Figure (4.21), wherever there was no shading of windows, the SHG was increased. In addition, it was increased wherever the positions of the windows facades and areas changed. Starting with NE, NW, SE, and SW. For example, NE facade, in case of W1 with single glazing system, the SHG was 817.32 W/m2, while in case of W2, the SHG was 525.42 W/m2. While SW facade, in case of W1 with single glazing system, the SHG was 1428.84 W/m2, while in case of W2, the SHG was 918.54 W/m2. On the other hands, using double glass windows, the SHG was 723.24 in the

103

elevation of NE in case of W01, while it was 464.94 for W02. Whether using Single glazing, double glazing or triple glasses. Whenever the area was fewer, the sensible heat gain was minimized. However, Heat-Absorbing Double Glass was the effective solution to reduce the sensible heat gain through the glass in case there is no shading and less area. Also, NE, and SE windows have gained the same amount of heat. As shown in Figure (4.22), these results were different when using shading devices. Wherever there were shading of windows, the SHG was minimized. However, it was increased wherever the positions of windows facades and areas were changed. Starting with NE, NW, SE, and SW respectively. For example, NE facade, in case of W1 with single glazing system, the SHG was 399.84 W/m2, while in case of W2, the SHG was 257.04 W/m2. While SW facade, in case of W1 with single glazing system, the SHG was 732.06 W/m2, while in case of W2, the SHG was 470.61 W/m2. On the other hands, using double glass windows, the SHG was 361.62 W/m2 in the elevation of NE in case of W01, while it was 232.47 in case of W02. SW elevation, the SHG was 649.74 in case of W01, while it was 417.69 in case of W02. So, it is important for designers to integrate shading devices in their planes of constructions. Also, SHG and GLF can help them to identify which type of glazing can be used. It is concluded that there are three parameters are responsible for increasing the sensible heat gain inside the zones: the area of windows, the type of glazing systems and their directions.

600 400 200 0 area of area of area of area of area of area of area of area of W01 W02 W01 W02 W01 W02 W01 W02 SINGLE GLASS DOUBLE GLASS Heat-Absorbing Clear Triple Glass Double Glass

NE NW SE SW

Figure (4.22): Sensible heat gain through shaded glass by using GLF

The next step is to identify solar transmission (ST) throw fenestration using (0.6- 0.5) values of SC. This would be according to Equation (4.7). Hourly SCL was defined using tabulated values that available in the ASHRAE fundamental handbook 2001. Also, it displayed a comparison between shading coefficient of reference cases and fenestration using shading devices. The results showed that low emissivity glass and

104

double allowed less solar transmission through without shading, as shown in Figure (4.23) for zone NE. Wherever there were shading, solar transmission through the fenestration become more effective. According to their reference SC values, we arrange the types of glass into four groups descendingly. This was to recognize which type had the less solar transmission. These groups were 1. Single glazing, 2. Double glazing 3mm thickness, double glazing 6mm thickness, 3. 3mm triple glazing, and 4. Double glazing emissivity glazing. The results showed that 6mm single glazing (SC=0.94) was the most type that allows sunbeams to go through space, but, whenever we take care of using shading devices in our planes, we can cut down solar transmission through the glass about 46.75%. Then, double glazing systems, these types allow solar transmission through it but less than the former one. Whether its thickness is 3mm or 6mm (SC was ranged between (0.88-0.79), solar transmission through the glass was less than the former type. But, whenever the design was with the shading devices, solar transmission reduced about 43-36%. Whenever shading coefficient was less than 0.6 as was in emissivity glazing, solar transmission through the glass was less than the former groups, it was reduced about 30-80%. One can notice that the emissive glass inherent less ST. These results were found in the four zones, but SW was more ST than the other zones due to its more exposure to the sun especially in summer.

15000 10000 5000

Air

3mm

SglLoE

3mm 6mm

DblLoE

Glazing

16mm

DblClr

glazing

spacing spacing

(e2=.4) Clr

(e3=.1) Clr

16mm 16mm ɛ4

3mm/6mm

6mmSingle

3mm/13mm

tribleGlazing

glazing6mm

6mmdouble 6mmdouble 6mm double

NE ST of Ref W1 ST of Ref W2 ST of SC=0.5 W1 ST of SC=0.5 W2

Figure (4.23): A comparison ST through examined glasses for L5-NE

Discussion To obtain NZEB, this study claimed that the desired SC, in case of using natural ventilation, should be between 0.5-0.4. In case of using the mechanical and mixed ventilation, SC should be limited between 0.7-0.6. However, Farrar-Nagy, Anderson, Hancock, and Reeves (2000) stated that energy savings can be strongly achieved with

105

a high-performance glazing with a low shading coefficient. These values can be achieved by assistance software such as W7.5. The results of this study showed that these values can be gotten by using external blinds with 45˚ downward tilt. In the same context, Chua and Chou (2010) have found that the half egg-crate louver was the most suitable SHDs for residential buildings facing the north and south orientations in the hot climate, whereas a horizontal projection with 30˚ downward tilt was appropriate for facade facing the east and west orientations to reduce cooling load. Also, they indicated that low-E single clear glazing may be a suitable glazing since it results in relatively economical short payback periods. However, sensible heat gain and solar transmission through fenestration knowledge can avoid more heat gain inside the space, as a result more energy savings taking into consideration that there are three parameters that are responsible for increasing the sensible heat gain inside the zones: the area of windows, the type of glazing systems, and their directions. In contrary, Lau, Salleh, Lim, and Sulaiman (2016) recommended to use shading devices on low performance glazing since the energy savings will be more significant than when using high performance glazing. The sun is an awesome element that available in Gaza throughout the year. For that, shading coefficient SC, solar heat gain SHG and solar transmission ST can help us to decide which type of glass can allow less solar heat gained, whether it transmitted or reflected. They can be calculated by manual calculations in order to estimate the cooling loads of air conditioning system. But nowadays, finite element and condition boundary methods facilitate this mission. So, shading coefficient has a good role to get energy efficiency of the envelope in order to achieve NZE.

4.1.3 Airtightness Air tightness is a term that indicates an infiltration occurred due to air leakage through the fabric of the building. Most cold countries used it to prevent cold air flow to the spaces. This act would reduce the heating loads. But, our case as well Gaza, is different. Dessert climate, hot air stream in the summer may have different result about cold countries. So, our examined zones were L01-SW, L04-SW, and L08-SW. The procedure was separately involving thermal break of frames of windows and using an excellent crack template of airtightness for external envelope. The excellent crack

106

template is available in DesignBuilder with other levels of air tightness. The infiltration rate was fixed to 1 ac/h a day; less than 0.35 ac/h is not healthy (Mudarri, 2010). It is worth to mention that our case is to get NZE building of existing building envelope. The selected case of external walls was case 06. Its specifications was mentioned to in Table (4.1). By using mixed mode ventilation, the impact of airtightness slightly occurred on cooling loads. Heating loads were almost faded away, but the cooling loads minimized. Firstly, thermal breaks of Polyvinylchloride (PVC) were used to prevent outdoor air to enter the spaces. PVC thermal properties were defined by PEC: thermal conductivity was 0.19 w/m.k, specific heat was 900 J/kg.k, and density was 1200 kg/m3. As shown in Figure (4.24), using the thermal break for frames of windows annually decreased heating load (AHL) about 79.05%, and 89.21% in the zones of L01-SW, and L08-SW respectively. But, in the middle of the building of QEAB, definitely, L04-SW, AHL decreased about 100%. On other hands, cooling load (ACL) decreased about 10.77%, 8.18 and 6.22 in the zones L01-SW, L04-SW, and L08-SW respectively. AL decreased about 21.09% in the zone L01-SW, and it was about 11.72% in the zone L04-SW, also, it was about 16.18% in the zone L08- SW. On the other hands, as a result of using excellent air tightness template, generally, as shown in Figure (4.24), both of AHL and ACL minimized. The results were close to the values that mentioned in the case of thermal break. Using the excellent crack template of air tightness decreased AHL about 78.87%, and 89.23% in the zones of L01-SW, and L08-SW respectively. But, L04-SW, AHL decreased about 100%. ACL decreased about 10.77%, 8.17 % and 6.22% in the zones L01-SW, L04-SW, and L08- SW respectively. Annually, the impact of excellent air tightened zone was by minimizing the loads about 21.07% in the zone L01-SW, and it was about 11.71% in the zone L04-SW, also, it was about 16.18% in the zone L08-SW. Partially, airtightness can reduce the loads for the buildings. The impact was more on the lower floor, then was in the upper floor. But it was less on the middle floor. Due to the fact of driven forces by pressure and wind stack effect, as shown in Figure (5.38), the level of unit air tightness was necessary to control stack effect air pressures and to limit airflow from adjacent units and cross contamination (Kohta Ueno, Joseph Lstiburek, & Bergey, 2012). Taken into consideration that All examined zones located in the leeward elevation (low pressure) and L4 was a neutral pressure.

107

10.00

5.00 MWh 0.00 AHL ACL AL AHL ACL AL AHL ACL AL

L01-SW L04-SW L08-SW REF FRAME EXC Figure (4.24): The impact of thermal break and excellent crack templet on ALs.

Discussion: This study adapts airtightness in order to get NZEB. Energy savings were ranged between 11.71-21.07%. IEA (2013a) stated that about 20-30 % of the heating demands can be decreased by only air sealing measure. The airtight fabric prevents heat transfer from or to the buildings. If it coupled with appropriate ventilation control, it would ensure the indoor climate is healthy. El-Darwish and Gomaa (2017) showed that simple retrofit strategies such as solar shading, window glazing, airtightness can reduce the energy consumption by an average of 33%. In order to get a satisfied level of thermal comfort in the retrofit projects, it is recommended to include the airtightness strategy into the ventilation study.

4.1.4 Green roof (GR) Green roof (GR) is commonly used in the contemporary buildings wherever the designers call for sustainability. This scenario is to prevent the sun direct beam to penetrate through the roof. For its importance, DesignBuilder enables designers to simulate vegetation layers on the roofs. In case of QEAB, implementing GR decreased the annual load about 8.76% for zone L8-SW, as shown in Figure (4.25). Taking into account many changeability factors such as a height of plants, moisture factor, leaf reflectivity, leaf emissivity, vapor resistance and stomatal resistance, as shown in Table (4.6). However, these factors were detected by DesignBuilder as a template that built in the software. In fact, cool material technology as well as GR are found in Gaza in some buildings that used pots to grow up plants on roof or on elevations but it was not considered as basic layer of roof.

108

7.50

5.00 MWh 2.50 0.00 AHL ACL AL REF GR Figure (4.25): The impact of implementing green roof on heating and cooling loads

Table (4.6): GR specifications as built-in DB

minimum stomatal resistance (s/m) 100.00 height of plants 10 cm max volumetric moisture content at saturation 0.50 Leaf area index (LAI) 5.00 min residual volumetric moisture content 0.01 leaf reflectivity 0.22 initial volumetric moisture content 0.15 leaf emissivity 0.95 moisture diffusion calculation method simple Discussion: Using GR in the existing building is too critical since there is an extra load on the roof which should be taken into account in civilian calculations. The more the height of plants, the weight increases and the effect on heating and cooling loads would be more effective. Berardi (2016) clarified that the adoption of a green roof retrofit resulted in a building energy demand reduction of 3%, and that significantly improved indoor comfort levels in the floor below the green roof. The parametric analysis of different green roof options showed that, for building energy savings, increasing the soil depth is more important than increasing the leaf area index. Taleb (2014) has revealed the total annual energy consumption of a residential building in Dubai may be reduced by up to 23.6% when a building uses a high level of insulation. One type of insulation that can reduce the heat conduction that enter to the interior of the building is the green roof with different layers consisting of drainage and barriers for roots plus channels for water which are recommended in this study. Summary: To get an energy efficiency envelope as the first step toward NZEB in multi-storey buildings, the low thermal transmittance of the envelope configurations are recommended. On the other hands, SHDs have the significant role for reducing the energy needed to cool space taking into consideration many issues that can effect on their function: the area of windows, glazing systems, window orientation, in addition to, open ground floor, and neighboring buildings. A good shading management leads to significant energy savings. Their forms can be expressed by low shading coefficient.

109

This type can be perceived by a combination of OHs, SFs, and LOs type (2), their effect can be shown in Figure (appx 1.1). But, the correlated issue that appears in presence of fixed shading devices is to reduce of heating loads in winter, as shown in Figure (appx1.2). Also, in case that the airtight strategy incorporated with a good type of ventilation, the buildings become healthier. On the other hands, green roof or any transpiration means (plants, water) can perfectly insulate the upper floor from the sun heat, and so does to veil a sunny exposure surfaces.

110

Chapter 5 The role of NZER process in improving the ventilation

111

Chapter 5 The role of NZER process in improving the ventilation

Introduction

The ventilation is a crucial element in Gaza, especially in the summer. The electricity situation makes it a complicated issue for achieving a comfort level for occupants. Generally, to overcome this problem, people used to install air conditioning unit (AC) or individual fans in their apartments in order to use them whenever the electricity is available. But, the majority has depended on an Uninterruptible power supply UPS in case of electricity cut which sometimes get to be available just for four hours. This cannot be enough to operate AC unit or fans for a long time. This chapter provides many concepts to get natural ventilation in QEAB. Then, it suggests the possibilities of using mechanical ventilation and mixed mode ventilation in the building. Case 06 of the envelope construction was selected as a reference case (RC), for more details, see Table (4.1). The selected zones were NE, NW, SE, and SW in the fifth floor. So, this chapter is the answer to question no. four: What are the proposed scenarios of ventilation using the building envelope in Gaza in order to get NZEB?

5.1 Natural ventilation

As known, some traditional buildings were found depending on the courtyard in their configurations. Likely, this concept was suggested to apply in QEAB using the main shafts of the building. The beginning was with the RC thermal conditions. AV of AT, FAF, and SHG in the zones NE, NW, SE, and SW respectively were as follows: - As shown in Figure (5.1), in summer, AV of AT were 33.91, 33.46, 34.95, and 34.86ᵒC. While AV of RT were 34.79, 34.35, 35.73, and 35.65ᵒC. In winter, AV of AT were 21.01, 21.90, 23.04, and 23.40ᵒC. AV of RT were 20.92, 22.04, 23.04, and 23.81ᵒC. - As shown in Figure (5.2), in summer, AV of FAF was 2.01, 2.17, 1.28, and 1.37 ac/h. in winter, it was 0.33, 0.39, 0.25 and 0.44 ac/h.

112

- As shown in Figure (5.3a), in summer, SHG was 26.65, 24.81, 30.04, and 28.85 kWh. In winter, it was 12.12, 22.86, 21.83, and 32.42 kWh. HLg was 9.77, 9.35, 10.95, and 11.01. In winter, it was 13.96, 15.26, 16.81, and 17.37 kWh. HLw was 12.50, 11.79, 14.89 and 15.30 kWh in summer. In winter, it was 20.29, 22.98,

25.79, and 27.34kWh. HLif was 25.94, 26.36, 23.97, and 24.16 kWh in summer. In winter, it was 8.88, 11.53, 8.49, and 14.87 kWh.

40.00 40.00 ᵒC

20.00 ᵒC 20.00

0.00 0.00 NE NW SE SW NE NW SE SW a. Summer AT °C RT °C DBT °C b. Winter AT °C RT °C DBT °C Figure (5.1): AT, RT, and DBT of the examined zones (RC)

2.00 2.00

1.00 1.00

ac/h ac/h

0.00 0.00 NE NW SE SW NE NW SE SW a. Summer b. Winter Figure (5.2): FAF of the examined zones (RC)

NE NW SE SW 40.00 20.00 0.00 kWh -20.00 -40.00

Glazing Walls External Infiltration SHG a. Summer

NE NW SE SW 40.00 20.00 0.00 kWh -20.00 -40.00

Glazing Walls External Infiltration SHG b. Winter Figure (5.3): heat gain and loss of the examined zones (RC)

113

a. Summer b. winter Figure (5.4): The typical behavior of temperatures, and HGLG, of the examined zones (RC)

Discussion: the indicators of AT, RT, and heat loss and gain pointed that the examined zones had the hot circumstances. Two main factors were responsible to heat up the zones. They were: 1) sensible heat gain due to the assumption of full occupancy and appliance. Full occupancy was assumed as a constant case to predict the worst thermal possibilities that could happen. 2) Solar heat gain through windows. Altitude angle and the area of windows demonstrated on the amount of solar radiation that gets into the zones. Windows facing the southeast and southwest elevations are the most elevations exposed to the sun, as shown in Figure (5.5). On the other hands, heat loss flow through glazing, walls, and infiltration which originally happened due to the fact that the heat flows from hot areas to cold areas. Whereas the amount of air that delivered into the zones by opening the windows was more in the northern zones because they were colder. These circumstances would be a motivation to find ways to mitigate their effect in presence of natural ventilation. AT, RT, FAF, and SHG and HL would be observed on the following procedures. So, the study suggested many passive strategies that depended on mitigating the indoor air temperature, cutting down the solar heat gain, increasing the ventilation rate inside the examined zones. These strategies of ventilation were SHDs, wind catcher (WC), double skin faced (DSF), and a combination of double skin facade and vertical greenery systems (GDSF).

5.1.1 Natural ventilation in presence of shading devices (SHDs) According to the outcomes of category 4.1.2.6, if our scenario was intended for using natural ventilation, SC should be less than 0.5-0.4, referring to Figure (4.17). The results showed that: AVs of AT and RT declined in the zones NE, NW, SE, and SW, as follows:

114

a. Summer b. Winter Figure (5.5): Sun path in summer and winter design weeks using Ecotect

- As shown in Figure (5.6a), in summer, AV of AT declined about 3.23, 3.67, 4.10, and 4.22 ᵒC respectively. AV of RT declined about 3.82, 3.83, 4.57, and 4.60 ᵒC respectively. - As shown in Figure (5.6b), in winter, AV of AT declined about 0.56, 2.18, 1.97, and 3.25 ᵒC respectively. AV of RT declined in the zones NE, NW, SE, and SW. it was about 0.86, 2.43, 2.37, and 3.71 ᵒC respectively.

As for AV of FAF, In general, the results showed that it increased in the examined zones: NE, NW, SE, SW, as follows: - As shown in Figure (5.7a), in summer, it increased about 62.95, 67.95, 66.05, and 65.61% respectively. - As shown in Figure (5.7b), in winter, it increased about 20.55, and 10.53% respectively. While it decreased in the zones NE, and SE. it was about 30.30, and 33.06% respectively.

40.00 40.00

30.00 ᵒC 20.00 ᵒC 20.00 10.00

0.00 0.00

RC RC RC RC

SHDs SHDs SHDs SHDs

SHDs SHDs SHDs SHDs NE NW SE SW NE NW SE SW a. Summer AT °C RT °C DBT °C b. Winter AT RT DBT Figure (5.6): AT, RT, and DBT of the examined zones in comparison with RC (SHDs)

115

6.00 6.00 4.00 4.00

ac/h 2.00

0.00 0.00

RC RC RC RC

SHDs SHDs SHDs SHDs

SHDs SHDs SHDs SHDs NE NW SE SW a. Summer b. Winter NE NW SE SW

Figure (5.7): FAF of the examined zones in comparison with RC (SHDs)

Also, the results showed that AV of SHGw, HLg, HLw, and HLE declined in the examined zones: zone NE, NW, SE, and SW, as follows: In summer: As shown in Figure (5.8a),

- AV of SHGw declined about 70.84, 69.37, 73.17, and 70.45% respectively. - AV of HLg declined about 66.12, 74.33, 67.85, and 70.27% respectively. - AV of HLw declined about 78.08, 90.84, 83.21, and 80.46% respectively.

- AV of HLE declined about 19.67, 11.47, and 5.96% respectively. While it increased about 4.42% in the zone NW.

In winter: As shown in Figure (5.8b),

- AV of SHGw declined about 58.25, 79.39, 86.99, and 80.69% respectively. - AV of HLg declined about 22.06, 34.21, 30.39, and 38.76% respectively. - AV of HLw declined about 3.89, 24.90, 19.78, and 34.59% respectively.

- AV of HLE declined about 34.46, 4.82, 44.17, 21.69 % respectively.

30.00 10.00 -10.00 kWh -30.00 RC SHDs RC SHDs RC SHDs RC SHDs NE NW SE SW a. Summer Glazing Walls External Infiltration SHG

30.00 10.00

kWh -10.00 -30.00 RC SHDs RC SHDs RC SHDs RC SHDs NE NW SE SW b. Winter Glazing Walls External Infiltration SHG Figure (5.8): HLG the examined zones (SHDs)

116

a. Summer. b. winter

Figure (5.9): The typical behavior of AT, and HGLG of the examined zones (SHDs)

Discussion: SHDs were able to reduce the areas and time in which the envelope components were exposed to the sun. This led to mitigate the AT by about 3.23-4.10 ᵒC which increased the air movement that it expressed by FAF. Referring to category 4.1.2 recommendations, low SC is required in case of natural ventilation. This can particularly be beneficial in summer, but solar radiation is desirable in winter. For that, operable or adoptive windows can response to the daytime solar radiation and altitude angles can reduce the need for cooling and heating space. On the other hands, DB in case of natural ventilation considers windows closed in winter. Glazing reflects back part of the zones heat especially that glazing here is low-E panes (BBSA, 2016). Also, the zones experienced the radiative heat loss because of the overcast days and nights in winter (EWC, 2013). In contrary, Koo, Lee, An, and Lee (2017) proposed a ventilated double skin windows without a shading device in order to reduce the heat transfer by naturally ventilating the inside of the air cavity whose temperature increases due to conduction (solar chimney effect). Therefore, the SHGC can be lowered through ventilation by 28% to 52.9%. It is concluded that SHDs are not the only way to veil surfaces to the sun. So, it is recommended that a natural ventilated glazing system management, as well as double skin windows, will be a good strategy for the subject of NZEBs.

5.1.2 Natural ventilation in presence of windcatcher (WC) The idea of windcatcher WC is not new. It was adapted by former architects in the traditional buildings which was known as Malqaf. Its mechanism depends on catching the prevailing wind and monitoring it to enter into the building using tower which it

117

vertically built on the last roof as an extension of the main shafts, as shown in Figure (5.10). This process in fact called stack effect. Wherever the building faces the prevailing wind, the windward pressure is made which is almost high pressure in case no obstacles or parts of the building can change the wind behavior. Wherever there were projections or any obstacles, the wind changes its direction in leeward which is almost low pressure. These shafts were provided with vents located in the lower part of the zone. These vents were used to force the caught winds to enter the zone as a fresh air. In turn, on the other side, there were vents in the upper part of the zone. These vents mission was to withdraw the hot air to outside. Air replacement would be done to exchange the indoor air, especially in summer. As known, the prevailing wind in Gaza blows from the western northern direction. The previous vision was applied to QEAB, as shown in Figure (5.10).

Figure (5.10): Wind catcher pattern (WC1)

The results showed that AVs of AT, and RT declined in the examined zones i.e. zone NE, NW, SE, and SW, as follows: - As shown in Figure (5.11a), in summer, AV of AT declined about 3.98, 4.12, 5.10, and 5.11 ᵒC respectively. AV of RT declined about 4.37, 4.26, 5.27, and 5.27 ᵒC respectively. - As shown in Figure (5.11b), in winter, AV of AT declined about 1.31, 3.04, 2.67, and 4.16 ᵒC respectively. AV of RT declined about 1.36, 3.04, 2.82, and 4.34 ᵒC respectively.

As for AV of FAF, it increased in the examined zones, NE, NW, SE, and SW, as follows: As shown in Figure (5.12a), in summer, it increased about 71.37, 75.75, 74.95, and 74.15% respectively. As shown in Figure (5.12b), in winter, it increased about 19.51, 53.01, 10.56, and 48.55% respectively. The windows were 5% opened.

118

40.00 40.00

20.00 20.00 ᵒC

0.00 ᵒC 0.00

RC RC RC RC

SHDSWC SHDSWC SHDSWC SHDSWC

SHDSWC SHDSWC SHDSWC SHDSWC NE NW SE SW NE NW SE SW a. Summer AT RT DBT b. Winter AT RT DBT

Figure (5.11): AT, RT, and DBT of the examined zones in comparison with RC (SHDsWC)

6.00 6.00

4.00 4.00 ac/h 2.00 ac/h 2.00

0.00 0.00

RC RC RC RC

SHDSWC SHDSWC SHDSWC SHDSWC

SHDSWC SHDSWC SHDSWC SHDSWC a. Summer NE NW SE SW b. Winter NE NW SE SW Figure (5.12): FAF of the examined zones in comparison with RC (SHDsWC)

On the other hands, the results showed that AVs of SHGw, HLg, HLw, and HLE declined in the examined zones: zone NE, NW, SE, and SW, as follows:

- In summer, as shown in Figure (5.13a), AV of SHGw declined about 70.89, 69.37, 73.45, and 70.50% respectively. AV of HLg declined about 74.97, 80.21, 78.36, and 79.75% respectively. AV of HLw declined about 91.71, 101, 98.57, and

94.58% respectively. AV of HLE declined about 8.32% in zone NE. While it increased about 8.79, 7.63, and 9.21 in zones NW, SE, and SW respectively.

- In winter, as shown in Figure (5.13b), AV of SHGw declined about 58.25, 79.40, 68.99, and 80.69% respectively. AV of HLg declined about 29.15, 41.74, 35.93, and 45.79% respectively. AV of HLw declined about 14.14, 35.16, 27.64, and

43.95% respectively. AV of HLE declined about 14.76% in zone SE. While it increased about 0.89, 25.90, and 11.83% in zones NE, NW, and SW respectively.

30.00 10.00

kWh -10.00 -30.00 RC SHDSWC RC SHDSWC RC SHDSWC RC SHDSWC NE NW SE SW a. Summer Glazing Walls External Infiltration SHG

119

30.00

kWh 10.00 -10.00 -30.00 RC SHDSWC RC SHDSWC RC SHDSWC RC SHDSWC NE NW SE SW b. Winter Glazing Walls External Infiltration SHG Figure (5.13): HLG the examined zones (SHDsWC)

a. Summer b. winter

Figure (5.14): The typical behavior of AT, and HGLG of the examined zones (SHDsWC)

Discussion: Although sensible heat gain still depended on full occupancy, the results reflect that WC can maintain the indoor air quality. The AV of AT decreased by about 3.98-5.11ᵒC. The northern zones reposed to the practice of WC rather than the southern ones due to the fact that the later ones more facing to the south. Since heat transfers slowly through the fabric, HL decreased in summer (Taleb, 2014), in addition to, AT become close to the outdoor temperature. Except that, HL via infiltration appeared due to inadequate insulation for fabric. On the other hands, instead of orienting the building toward the prevailing winds, using simple forms of WC can capture the wind, then, enter it into the zones. The recent literature view used to combine WC with passive cooling auxiliaries, for example, Mourad, Ahmed Hamza, Ookawara, and Abdel-Rahman (2014) combined WC with an underground earth cooling tunnels in order to cool the inlet air. Consequently, instead of orienting the building toward the prevailing wind, WC could be coupled with the other passive strategies for cooling. Also, there are many bioclimatic studies used cooling pads or planting inside the WC to cool the inlet air by moisture. Thus, this study recommends using such as a simple form of WC to maintain the indoor air quality in the multi- storey buildings using the ventilation shafts.

120

5.1.3 Natural ventilation via double skin façade (DSF) The mechanism of double skin façade (DSF) was explained before in chapter (2), category 2.5.1.2. The idea was applied to the QEAB. The type of air flow was type 8, referring to Figure (5.16). The cavity in between both external walls was 30 cm. The outer layer was single glazing, but the inner one was low emissivity glass. Vents were supposed that they opened all the time. Also, airtightness was considered using the good crack template that is available in Designbuilder V5.

Figure (5.15): Double skin façade DSF

Figure (5.16): The airflow types of DSF

Source: (Hong et al., 2013) The results showed that AVs of AT declined in the examined zones: NE, NW, SE, and SW. - As shown in Figure (5.17a), in summer, AV of AT declined about 2.02, 1.97, 2.56, and 2.75 ᵒC respectively. AV of RT declined about 2.12, 2.05, 2.57, and 2.75. - As shown in Figure (5.17b), in winter, AV of AT declined about 1.1, 2.09, 1.16, and 2.12 ᵒC respectively. AV of RT declined about 0.63, 1.45, 0.67, and 1.50 ᵒC.

As for AV of FAF, it increased in the examined zones i.e. NE, NW, SE, and SW. - As shown in Figure (5.18a), in summer, it decreased about 72.11, 74.70, 79.87, and 80.78% respectively.

121

- As shown in Figure (5.18b), in winter, AV of FAF increased about 27.78, and 16.17% in zones NW, and SW respectively. While it declined about 30.30, and 25.34% in zones NE, and SE respectively.

40.00 40.00 ᵒC

ᵒC 20.00 20.00

0.00 0.00 RC DSF RC DSF RC DSF RC DSF RC DSF RC DSF RC DSF RC DSF NE NW SE SW NE NW SE SW a. Summer AT RT DBT b. Winter AT RT DBT Figure (5.17): AT, RT, and DBT of the examined zones in comparison with RC (DSF)

2.50 2.50 2.00 2.00

ac/h 1.50 1.50 ac/h 1.00 1.00 0.50 0.50 0.00 0.00 RC DSF RC DSF RC DSF RC DSF RC DSF RC DSF RC DSF RC DSF a. Summer NE NW SE SW b. Winter NE NW SE SW Figure (5.18): FAF of the examined zones in comparison with RC (DSF)

On the other hands, the results showed that AVs of SHGw, HLg, HLw, and HLE declined in the examined zones: zone NE, NW, SE, and SW, as follows:

- In summer, as shown in Figure (5.19a), AV of SHGw declined about 77.67, 85.32, 75.69 and 80.59 respectively. AV of HLg declined about 81.17, 81.86, 82.54, and 83.52 respectively. AV of HLw declined about 54.80, 60.66, 57.16, and 58.21%

respectively. AV of HLE declined about 87.13, 88.93, 88.96, and 89.27%

respectively. While AV of HLI increased about 26, 27.46, 27.36, and 27.32 kWh respectively.

- In winter, as shown in Figure (5.19b), AV of SHGw declined about 84.49, 71.22, 65.70, and 63.05% respectively. AV of HLg declined about 64.76, 72.54, 66.40, and 73.29% respectively. AV of HLw declined about 32.63, 36.25, 28.47, and

32.57% respectively. AV of HLE declined about 43.02, 1.47, 34.21, and 11.43%

respectively. AV of HLI increased about 14.76, 16.89, 16.03, and 21.66 kWh respectively.

122

30.00 10.00 kWh -10.00 -30.00 RC DSF RC DSF RC DSF RC DSF

a. Summer NE NW SE SW

Glazing Walls Internal Natural vent. External Infiltration SHGi SHGw

30.00

10.00 kWh -10.00 -30.00 RC DSF RC DSF RC DSF RC DSF

b. Winter NE NW SE SW Glazing Walls Internal Natural vent. External Infiltration SHGi SHGw Figure (5.19): HLG the examined zones (DSF)

a. Summer b. winter

Figure (5.20): The typical behavior of AT, and HGLG of the examined zones (DSF)

Discussion: the results showed that DSF can reduce the AV of AT between 1.97- 2.75ᵒC. But, heat loss and low fresh air flow rate indicated that the AT of examined zones was higher than the outdoor temperature. The performance of DSF was clear in reducing the inside air temperature and to cut down the areas that are exposed to the direct solar radiation. It behaved as a barrier against the external ambient, but, the scenario should be supported with shading devices installed in between its layers. Also, using single emissivity glass was insufficient to prevent heat flow to inside. However, many authors proposed some alternative notions of DSF in order to avoid its volume especially when it used in residential compounds. Cho and Cho (2018) proposed slim double skin window, as shown in Figure (5.21).

123

Figure (5.21): Slim type double skin window

They found that installation of the blind and the external window opening was the most appropriate setting for cooling load reduction in the summer as it blocked the introduction of solar heat to the interior and decreased the temperature of the air space. It confirmed its energy efficient performance. Mainly, NZEB requires a high performance for envelope components. So, it is recommended for DSF in Gaza to use an effective system taken into consideration the ability to minimize its volume.

On the other hand, if WC was integrated to the DSF scenario, it depended on that the operation of the vents and the openings were scheduled. Two cases, case 1 depended on that opening windows were totally opened throughout 24 hours in the summer, and they were partly opened at daytime in the winter. Case 2 depended on that the percentage of glazing area opens was 25% in summer and partly opening at daytime in the winter. The results showed that AVs of AT and RT declined in both of two cases, as follows: - As shown in Figure (5.22a), in summer, as for case 01, AV of AT declined about 3.14, 2.95, 3.72, and 3.78 ᵒC in zones NE, NW, SE, and SW respectively. AV of RT declined about 2.86, 2.69, 3.33, and 3.43 in the same zones respectively. As for case 02, AV of AT declined about 2.79, 2.59, 3.31, and 3.41 ᵒC. AV of RT declined about 2.64, 2.48, 3.10, and 3.21ᵒC.

124

- As shown in Figure (5.22b), in winter, as for case 01, AV of AT declined about 1.46, 2.92, 1.51, and 2.43 ᵒC in zones NE, NW, SE, and SW respectively. Also, AV of RT declined about 0.85, 2.11, 0.89, and 1.68ᵒC. As for case 02, AV of AT declined about 1.28, 2.22, 1.32, and 2.24 ᵒC. AV of RT declined about 0.76, 1.55, 0.78, and 1.58 respectively.

40.00 40.00 30.00 30.00

ᵒC 20.00

20.00 ᵒC 10.00 10.00

0.00 0.00

RC RC RC RC

DSFWC.SCH DSFWC.SCH DSFWC.SCH DSFWC.SCH

DSFWC-24on DSFWC-24on DSFWC-24on DSFWC-24on

DSFWC-24on DSFWC-24on DSFWC-24on DSFWC-24on NE NW SE SW NE NW SE SW a. Summer AT RT DBT b. Winter AT RT DBT

Figure (5.22): AT, RT, and DBT of the examined zones in comparison with RC (DSFWC)

As for AV of FAF, the results showed that it increased in the examined zones, i.e. NE, NW, SE, and SW, as follows:

4.00 4.00

2.00 2.00

ac/h ac/h

0.00 0.00

RC RC RC RC

DSFWC.SCH DSFWC.SCH DSFWC.SCH DSFWC.SCH

DSFWC-24on DSFWC-24on DSFWC-24on DSFWC-24on

DSFWC-24on DSFWC-24on DSFWC-24on DSFWC-24on a. Summer NE NW SE SW b. Winter NE NW SE SW Figure (5.23): FAF of the examined zones in comparison with RC (DSFWC)

- As shown in Figure (5.23a), in summer, as for case 01, AV of FAF increased about 39.15, 29.08, 31.55, and 25.04 % respectively. As for case 02, AV of FAF increased about 34.57, 22.78, 23.35, and 14.72 % respectively. - As shown in Figure (5.23b), in winter, AV of FAF increased about 2.94, 51.25, 9.71, and 28.81 % respectively. As for case 02, AV of FAF increased about 0.24, 38.10, 6.11, and 26.55 % respectively.

On the other hand, the results showed that AVs of SHGw, HLg, HLw, and HLE declined in the examined zones: zone NE, NW, SE, and SW, as follows:

- In summer, as shown in Figure (5.24a), AV of SHGw declined about 77.75, 85.33, 75.97, and 80.65% respectively. AV of HLg declined about 92.32, 91.98, 93.33,

125

and 93.73 respectively. AV of HLw declined about 68.88, 74.39, 69.38, and

69.25% respectively. AV of HLE declined about 13.81, 27.16, 11.39, and 15.05%

respectively. While AV of HLI increased about 13.38, 16.70, 15.44, and 14.96 kWh respectively.

- In winter, as shown in Figure (5.24b), AV of SHGw declined about 84.49, 71.22, 65.71, and 63.06% respectively. AV of HLg declined about 67.98, 76.74, 69.29, and 75.85 respectively. AV of HLw declined about 36.42, 43.69, 31.80, and

35.57% respectively. AV of HLE declined about 17.57, 22.72, 4.18, and 5.33%

respectively. While AV of HLI increased about 14.87, 18.50, 16.29, and 21.36 kWh in zone NE, NW, SE, and SW respectively. 30.00 10.00 -10.00

kWh -30.00

RC RC RC RC

DSFWC.SCH DSFWC.SCH DSFWC.SCH DSFWC.SCH

DSFWC-24on DSFWC-24on DSFWC-24on a. Summer DSFWC-24on NE NW SE SW Glazing Walls Internal Natural vent. External Infiltration SHGi SHGw 30.00 10.00 -10.00

kWh -30.00

RC RC RC RC

DSFWC.SCH DSFWC.SCH DSFWC.SCH DSFWC.SCH

DSFWC-24on DSFWC-24on DSFWC-24on b. Winter DSFWC-24on NE NW SE SW Glazing Walls Internal Natural vent. External Infiltration SHGi SHGw Figure (5.24): HLG the examined zones (DSFWC)

a. Summer. b. winter

Figure (5.25): The typical behavior of AT, and HGLG of the examined zones (DSFWC)

Discussion: whether the vents were opened all the time or were scheduled, the behavior of heat loss and gain was the same in case the scenario of DSF coupled with

126

wind catcher. But, if the vents were opened all the time, AV of AT declined by about 2.95-3.78ᵒC. If they were scheduled, AV of AT declined by about 2.59-3.41ᵒC. In context of natural ventilation, wind driven improved the behavior of DSF. But, if the vents were opened for 24h in summer, FAF become well than if the vents were scheduled. This disagrees with Sanchez, Rolando, Sant, and Ayuso (2016) who found that the DSF is better than the single skin facade when the vents only opened with solar radiation. Consequently, if these results compared with DSF scenario without WC, the found indicate that WC mitigate the AT and FAF simultaneously. Heat transfer was less than the case of DSF alone. So, using wind driven coupled with double skin facade is recommended.

5.1.4 Natural ventilation via greenery double skin façade (GDSF) The mechanism of greenery Double skin façade (GDSF) looks like the mechanism of DSF. Except that GDSF depends on using vertical greenery systems (VGS), as shown in Figure (2.26). This idea was applied to the QEAB. The type of system was indirect greenery system. In fact, the idea was a combination of DSF and VGS depending on the outer layer, if it was solid or translucent. Wherever there were opaque surfaces, GDSF was applied. Taking into consideration many factors as well as moisture factor, the height of plants, vapor resistance, these factors values were built in DesignBuilder, as shown in Table (4.6). Also, wherever there were translucent surfaces, DSF was applied, as shown in Figure (5.26). The height of plants was 10 cm. Case 06 was selected for the envelope construction (inner layer). The cavity between both external walls layers was 30 cm.

Figure (5.26): Applying GDSF on the QEAB

127

The results showed that AVs of AT and RT declined in the examined zones: NE, NW, SE, and SW, as follows: - As shown in Figure (5.27a), in summer, AV of AT declined about 2.02, 1.92, 2.83, and 2.86 ᵒC respectively. AV of RT declined about 2.71, 2.50, 3.42, and 3.43ᵒC. - As shown in Figure (5.27b), in winter, AV of AT declined about 0.78, 1.97, 1.32, and 2.32 ᵒC respectively. AV of RT declined about 0.51, 1.60, 1.07, and 2.06 ᵒC respectively.

As for FAF, the results showed that it decreased in the examined zones, as follows: As shown in Figure (5.28a), in summer, it decreased about 72.85, 74.37, 87.93, and 79.12 % respectively. In winter, as shown in Figure (5.28b), it decreased about 30.80, and 29.64 % in zones NE, and SE respectively. While it increased about 27.78, 15.53 % in zones NW, and SW respectively.

40.00 40.00 ᵒC 20.00 ᵒC 20.00

0.00 0.00

RC RC RC RC

GDSF GDSF GDSF GDSF

GDSF GDSF GDSF GDSF NE NW SE SW NE NW SE SW a. Summer AT RT DBT b. Winter AT RT DBT

Figure (5.27): AT, RT, and DBT of the examined zones in comparison with RC (GDSF)

2.50 2.50 2.00 2.00 1.50 1.50

ac/h 1.00 1.00 ac/h 0.50 0.50

0.00 0.00

RC RC RC RC

GDSF GDSF GDSF GDSF

GDSF GDSF GDSF GDSF a. Summer NE NW SE SW b. Winter NE NW SE SW Figure (5.28): FAF of the examined zones in comparison with RC (GDSF)

On the other hands, the results showed that AVs of SHGw, HLg, HLw, and HLE declined in the examined zones: zone NE, NW, SE, and SW, as follows:

- As shown in Figure (5.29a), in summer, AV of SHGw declined about 92.20, 92.44, 91.75 and 89.99%. AV of HLg declined about 87.09, 85.92, 89.54, and 88.59. AV

of HLw declined about 64.40, 68.27, 69.20, and 67.51%. AV of HLE declined

about 85.95, 87.14, 88.41, and 88.04% respectively. While AV of HLI increased

128

about 15.80, 18.17, 17.35, and 17.83 kWh in zone NE, NW, SE, and SW respectively.

- In winter, as shown in Figure (5.29b), AV of SHGw declined about 88.37, 78.70, 72.36, and 71.35%. AV of HLg declined about 71.12, 76.80, 72.67, and 77.51%.

AV of HLw declined about 31.31, 37.77, 31.89, and 37.05%. AV of HLE declined

about 40.11, 1.45, 38.20, and 12.65%. AV of HLI increased about 11.54, 11.46, 12.54, and 13.31 kWh in zones NE, NW, SE, and SW respectively.

30.00

10.00 kWh -10.00 -30.00 RC GDSF RC GDSF RC GDSF RC GDSF a. Summer NE NW SE SW Glazing Walls Internal Natural vent. External Infiltration SHGi SHGw

30.00

kWh 0.00

-30.00 RC GDSF RC GDSF RC GDSF RC GDSF b. Winter NE NW SE SW Glazing Walls Internal Natural vent. External Infiltration SHGi SHGw Figure (5.29): HLG the examined zones (GDSF)

a. summer b. winter

Figure (5.30): The typical behavior of AT, and HGLG of the examined zones (GDSF)

Discussion: in the cooling period, GDSF scenario provided a great potential to mitigate AT. RT indicator reflects that people could feel better. The AT and RT were approximate values in the majority of the day, also, at midday, it reduced RT by about 2ᵒC. Also, it reduced the amount of SHG through glazing. Also, it reduced the heat flow from the zones due to its unique feature of evaporative. This feature led to

129

improve the air temperature behavior inside the cavity, therefore, reducing the heat transfer via conduction led to cool down the temperature of surfaces. This agrees with Sheweka and Mohamed (2012) investigated the cooling potential on the surfaces of buildings via VGSs. They are beneficial elements during summer periods in hot climates due to their cooling effect that has an impact on the inner climate in the buildings. In winter, in order to make use of the solar radiation, using deciduous vines climber plants in such strategy is required. It is concluded for NZEBs to benefit from GDSF features to reduce the energy consumption, therefore, using deciduous vines climber plants are recommended. If WC was integrated to GDSF scenario, the results showed that AVs of AT and RT declined in the examined zones: NE, NW, SE, and SW, as follows: - As shown in Figure (5.31a), in summer, AV of AT declined about 2.91, 2.68, 3.63, and 3.72 ᵒC. AV of RT declined about 3.20, 2.96, 3.81, and 3.93ᵒC respectively. - As shown in Figure (5.31b), in winter, AV of AT declined about 0.98, 2.14, 1.50, and 2.46 ᵒC respectively. AV of RT declined about 0.65, 1.71, 1.19, and 2.14 ᵒC.

Also, the results showed that AV of FAF increased in the examined zones, as follows: As shown in Figure (5.32a), in summer, it increased about 28.28, 17.79, 17.42, and 15.18 %. As shown in Figure (5.32b), in winter, AV of FAF decreased about 2.17% in zones NE. While it increased about 37.15, 24.77 % in zones NW, and SW respectively.

40.00 40.00

20.00 20.00

ᵒC ᵒC

0.00 0.00

RC RC RC RC

GDSFWC GDSFWC GDSFWC GDSFWC

GDSFWC GDSFWC GDSFWC GDSFWC NE NW SE SW NE NW SE SW a. Summer AT RT DBT b. Winter AT RT DBT Figure (5.31): AT, RT, and DBT of the examined zones in comparison with RC (GDSFWC)

130

3.00 3.00 2.50 2.50 2.00 2.00 1.50

ac/h 1.50 1.00 ac/h 0.50 1.00 0.00 0.50

0.00

RC RC RC RC

GDSFWC GDSFWC GDSFWC GDSFWC

GDSFWC GDSFWC GDSFWC GDSFWC NE NW SE SW a. Summer b. Winter NE NW SE SW

Figure (5.32): FAF of the examined zones in comparison with RC (GDSFWC) On the other hand, the results showed that AVs of SHGw, HLg, HLw, and HLE declined in the examined zones: zone NE, NW, SE, and SW, as follows:

- In summer, as shown in Figure (5.33a), AV of SHGw declined about 83.30, 88.89, 82.16 and 85.25 respectively. AV of HLg declined about 92.73, 92.88, 93.15, and 94.13 respectively. AV of HLw declined about 73.44, 78.30, 75.49, and 75.57%

respectively. AV of HLE declined about 23.33, 33.09, 26.74, and 26.03%. While

AV of HLI increased to 5.30, 8.10, 8.51, and 8.12 kWh in zone NE, NW, SE, and SW respectively.

- In winter, as shown in Figure (5.33b), AV of SHGw declined about 88.38, 79.16, 72.36, and 71.35% respectively. AV of HLg declined about 72.08, 77.52, 73.39, and 78.06% respectively. AV of HLw declined about 33.98, 39.82, 34.07, and

38.92% respectively. AV of HLE declined about 16.61, 13.68 and 0.99 %

respectively. While it increased about 14.23 in zone NW. AV of HLI increased to 10.44, 10.49, 11.56, and 12.43 kWh in zones NE, NW, SE, and SW respectively.

30.00 10.00

kWh -10.00 -30.00 RC GDSFWC RC GDSFWC RC GDSFWC RC GDSFWC a. Summer NE NW SE SW Glazing Walls Internal Natural vent. External Infiltration SHGi SHGw

30.00 10.00

-10.00 kWh -30.00 RC GDSFWC RC GDSFWC RC GDSFWC RC GDSFWC

b. Winter NE NW SE SW Glazing Walls Internal Natural vent. External Infiltration SHGi SHGw

Figure (5.33): HLG the examined zones (GDSFWC

131

a. Summer b. Winter

Figure (5.34): The typical behavior of AT, and HGLG of the examined zones (GDSFWC)

Discussion: In addition to the previous discussion of GDSF, WC mitigates the rate of fresh air. This increased the heat loss via infiltration due to the fact that the heat flows from warm areas to cold ones. Meanwhile, WC could increase the heat loss through the fabric in winter. Heat loss occurred due to the cloudy times and nights circumstance. This means that there is the need to increase the insulation factor for the fabric. However, it can be avoided by using deciduous vines climber plants whose vines fall.

0.00 SW -15.00

RC SHDsSHDSWC DSF DSFWC GDSFGDSFWC kWh

-30.00

winter winter winter winter winter… winter winter

summer summer summer summer summer… summer summer

winter 24On winter summer 24On summer

RC SHDsSHDSWC DSF DSFWC GDSFGDSFWC

summer winter summer winter summer winter summer winter 24On summer 24On winter vent scheduled summer vent scheduled winter summer summer winter a. HL if winter SW 40.00 30.00 8.00 20.00

4.00 10.00

ac/h 0.00 0.00 kWh

-10.00

winter winter winter winter winter

winter -20.00

summer summer summer summer summer… summer summer

winter 24On winter -30.00 summer 24On summer

-40.00 winter scheduled… winter RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC Glazing Walls SHG b. FAF SW c. SHG, HLg, and HLw Figure (5.35): SHG. FAF, and HL for SW zone

132

Discussion for natural ventilation: The results showed many issues that should be taken into consideration in the subject of NZEB. These issues lead to energy savings in the existing buildings. Air replacement achieved in case of shading the fabric, for example zone SW, as shown in Figure (5.35). This was clear in case of using WC, in addition to, SHDs or means as a barrier between outdoor and indoor such as DSF and GDSF. SHDs reduce the SHG at the same time they led to increase the heat loss through the fabric. SHDs are beneficial in summer but they are not desirable in winter. DSF and GDSF were able to minimize the amount of SHG that get into the zone as well as they minimize the heat loss through the fabric. There are many factors plays in improve the natural ventilation, they are: Indoor air temperature: Table (3.2), returning back to our procedure in the study simulation which depended on its exaggeration assumption of space usage, it assumed full occupancy and depended on a systematic certain percentage of usage of appliance and equipment. This generated high sensible heat gain that heats up space. This was especially when air movements depended on mitigating the AT by passive strategies such as stack effect and SHDs scenarios. This agrees with Kamal (2012) who stated that passive cooling systems use non-mechanical methods to maintain a comfortable indoor temperature are a key factor in mitigating the impact of buildings on the environment. In Figure (appx 1.3), the average AV of AT and RT differed according to the strategy that is used for natural ventilation for QEAB. In case of RC, AV of AT was ranged between 33.91-34.86 ᵒC in the examined zones. By applying SHDs in summer, it declined about 3.23-4.22 ᵒC. Al-Tamimi and Fadzil (2011) found that a maximum reduction of 5.1 and 1.4 ᵒC in indoor temperature could be achieved by adding egg crate shading devices to un-shaded windows in unventilated and ventilated rooms, respectively. On the other hand, if WC was integrated to the SHDs, AT declined about 3.67-5.11 ᵒC in the examined zones. Spentzou, Cook, and Emmitt (2014) showed that the greatest improvement in terms of passive cooling ventilation such as WC reduces air temperature to (up to 1ᵒC reduction) and refresh air provision. In case of the adaption of the scenario of DSF, AV of AT declined about 1.97-2.75ᵒC in the examined zones. Hong et al. (2013) claimed that DSF is one of the summer strategies that was optimal with an energy saving rate of 12.67%. Moreover, using WC with DSF declined the AT about 2.95-3.78 ᵒC. If the windows opening was scheduled,

133

AT declined about 2.59-3.41 ᵒC in the examined zones. Spentzou et al. (2014) found that a reduction in indoor air temperature was predicted by using DSF with WC in rooms where there was previously no direct access to fresh air to enter through. If GDSF combination was applied, AT declined about 1.92- 2.86 ᵒC in the examined zones. Pérez, Coma, Martorell, and Cabeza (2014) found that a direct relation between foliage thickness and the surface temperature reduction, so that the thicker the foliage, the higher the reduction for double-skin green façades. Jaafar, Said, Reba, and Rasidi (2013) found there is a change in temperature that consistently occur on average 1.5 ᵒC at the high-rise building. Also, the living wall reduced indoor air temperature up to 4.0 °C (Safikhani, Abdullah, Ossen, & Baharvand, 2014) Fresh air flow (FAF): As shown in Figure (appx 1.4), FAF of RC of the examined zones was ranged between 1.28-2.17 ac/h. In case of implementing SHDs, FAF increased to 3.77-6.77 ac/h inside the examined zones. As for the scenario of SHDs with WC, FAF increased to 5.11-8.95 ac/h. In the scenario of DSF, FAF ranged between 0.26-0.56 ac/h. If WC was incorporated with DSF, FAF was ranged between1.83-3.30 ac/h. In case DSF’s vents were scheduled, FAF was ranged between 1.61-3.07 ac/h. As for the scenario of GDSF, FAF was ranged between 0.27-0.56 ac/h. If WC integrated into the scenario of GDSF, FAF was ranged between 1.55-2.80 ac/h. One can notice that incorporating WC with the SHDs, DSF, and GDSF scenarios increases the fresh air flow rate inside the examined zones. Spentzou et al. (2014) stated that the volumetric flow rate of fresh air in the spaces increased by up to nine times with the integration of the wind-catcher in the building design. Muhsin, Mohammad Yusoff, Mohamed, and Sapian)2016( claimed that WC is necessary for comfort and health reasons and it is an important parameter for the comparison of the different void configurations. Their study revealed that the provision of the void can enhance natural ventilation performance in multi-storey housing with an increase in the value of FAF from 3.44% to 40.07%, by enlarging the void’s width by 50% compared to the existing void. Solar heat gain (SHG): Referring to Figure (appx 1.5), it decreased in the scenarios. The minimal amount of SHG was in case of DSF, and GDSF scenarios. Khoshbakht, Gou, Dupre, and Altan (2017) stated that DSF can reduce the impact of

134

this solar gain by allowing shading devices to be installed in the cavity between the two skins, preventing sunlight from reaching the inner skin. Azarbayjani (2010) referred that designers and engineers can continue to improve the building envelope and facade treatments to reduce heat loss and solar gains through the windows, thereby decreasing heating and cooling requirements and minimizing differences between indoor air and surface temperatures that may cause occupants discomfort. However, Khoshbakht et al. (2017) found that DSFs reduce heat losses through ventilation. Figure (appx 1.6) displays the heat loss and gain through the fabric. The most heat loss occurred through opening the external windows and also it happened through inner windows of DSF. But, lower value was in case of GDSF. In summer, although SHDs with WC achieved the lowest rate of AT and the higher rate of FAF, the other cases showed that RT was higher than AT which means that the space needed to more insulation especially in partitions, floors and ceilings. The previous results indicate that there is the need for assistance axillaries for ventilation. Also, when occupancy and lighting and appliance operation are scheduled, the results would be more impressive. Section 5.2, and 5.3 are looking for using mechanical ventilation and mixed mode.

5.1.5 Computational fluid dynamics CFD CFD is the term used to describe a family of numerical methods used to calculate the temperature, velocity and various other fluid properties throughout a region of space (DesignBuilder V5). In this section, the process of CFD simulation tool in DesgnBuilder V5 will discuss four main domains: the possibility of implementing windcatcher WC to the main shafts of QEAB, and so done for glazing skylight. In addition, it displays the air flow behavior of DSF and GDSF scenarios. Also, it concerns about the possibility of using thermal mass for flooring. Also, it kept an eye on two factors: air velocity, and age of air (AA). Aforementioned categories aim to encourage designers to invent methods that could depend on natural ventilation in order to reduce energy consumption in the buildings therefore, it represents as an introduction to performing NZE strategy in GAZA buildings.

135

Figure (5.36): Section of the site

At first, Figure (5.36) displays site prevailing wind and pressure zones of RC. As known that in front elevation, that faces the wind (windward), is high-pressure zone- shown in a red area, while rare elevation (leeward) is low-pressure zone- shown in a blue area. Prevailing wind direction was defined by weather data file which is the northeast wind that swerves about 340ᵒ counterclockwise from east. The right side of the figure is the northern direction. Also, the left side is the southern direction.

SW NW SE NE

a. Western zones b. eastern zones Figure (5.37): Longitudinal sections of the RC

136

Figure (5.38): Stack effect in multifamily buildings (simplified), showing shaft effects

Source: (Kohta Ueno et al., 2012) Airflow fluxes and their distribution for certain building occur due to pressure differences caused by wind and thermal buoyancy (Feustel & Diamond, 1998). The exacerbated problems that correlated with stack effect is motivated by the presence of multi-storey shafts, i.e. elevator shafts, stairwells and ventilation shafts. Their stack- driven pressure differences across their walls results in an additional potential air transfer path, as shown in Figure (5.38), (Kohta Ueno et al., 2012). Also, the pressure inside the shafts was higher than the pressure that was in windward. This stimulated the air kept going drawn to upward, as shown in Figure (5.39a,b). Generally, air temperatures were ranged between 29.99-35.15ᵒC, also air velocity ranged between 0.15-1.63 m/s. SW SE NW NE

a. southern zones b. northern zones Figure (5.39): Air velocity inside the main shafts of the RC

137

SW NW

SE NE

Figure (5.40): AA inside the fifth-floor zones of RC

Referring to item 5.1, the researcher manages to explain the scenarios of natural ventilation using CFD. Figure (5.40) displays the age of air (AA) - which is the average time elapsed since molecules of air at that location entered the building- was calculated by LMA tool. The air existence differed in each zone of the fifth floor i.e. zone L5- NE, the newest air was from the northern windows. But, the oldest one was close to the staircase in which AA was 1064 sec (17.7 min). The result was verse in zone NW, the newest air was from the western windows, but, the oldest one was 528.52sec (8.8 min). In case of zone SE, the peak of AA was exist around the staircase which it was 600.52 sec (10min). The new air inlet from the southern side. For SW, max AA was in the majority of the zone which it was 959.52 sec (16min). The previous result showed that there is a need to air replacement system that it can renovate the air inside the zones especially around the staircase. So, in the following sections, air movements depend on stack effect and solar chimney strategy effect (that are explained before in section 2.5.1.1) in order to cool down the air temperature of zones also, air replacement.

5.1.5.1 Windcatcher (WC) This section will discuss two patterns of WC inspired from the traditional one.

Pattern one (WC1) was previously discussed in section 5.1.2. Here, the researcher will

138

focus on the CFD simulation. The concept as shown in Figure (5.10) was stood up of the last roof. Its shape was curved to encourage and capture the prevailing wind to enter the shafts. The wind catcher was covered with the wooden pergola. SHDs were installed to the external windows that achieved SC of (0.5-0.4), referring to Figure (4.17). CFD boundary conditions were adjusted depending on the summer design week in DesignBuilder. CFD simulation showed that the temperature was ranged between 26.53-31.99 ᵒC. As shown in Figure (5.41), the lowest AT was in the three lower zones in the first, second and third floors especially the areas that were limited to the staircase and the shaft. Then, the indoor temperature was increased whenever we go up. The fourth, fifth and sixth floors recorded 30ᵒC. The seventh floor had 30.50ᵒC. but the max air temperature was in the eighth floor which it was 31ᵒC. The Air flowed through the windows and also, the lower vents to the zones. The velocity was ranged between 0.06-0.69m/s. As shown in Figure (5.42), and Figure (5.43), air movement was noticed inside the zones especially in the upper zones. The pressure was -908 Pa. the air velocity increased upward. As shown in Figure (5.44), LMA tool calculated the AA inside zones, for example, the fifth floor. The max AA in zone L5-NE was 1050 sec (17.5 min). The max AA in zone L5-NW was 1425 sec (23.75 min). The max AA in zone L5-SE was 1077 sec (17.95 min). The AA in zone L5-SW was 1138 sec (18.97 min). The age of air reflected the ability to make the air stayed in the space, this can happen when the air was moisture. The particles of air stay more in order to mitigate the indoor air temperature.

a. Western zones b. eastern zones

Figure (5.41): Longitudinal sections of the WC1

139

a. southern zones b. northern zones Figure (5.42): Air velocity inside the main shafts of the pattern 01 wind catcher

Figure (5.43): Air velocity and pressure inside the main shafts of the pattern 01 wind catcher

SW NW

SE NE

Figure (5.44): AA inside the fifth-floor zones of WC1

140

Pattern two (WC2) is the same as pattern one except that the WC was inspired from Figure (5.45). WC2 stood up the last roof. Its shape was a tower incorporated cross bevels (wooden partitions) in order to reduce the turbulence of the entered prevailing wind. Cellulose evaporator (cooler pad) was installed inside the shaft in order to mitigate and moisture the entered wind. Also, SHDs were installed to the external windows. CFD boundary conditions were adjusted depending on the summer week design in DesignBuilder. CFD simulation showed that the temperature was ranged between 18.58-31.45 ᵒC. As shown in Figure (5.46), AT was ranged between of 27.16- 29.31 ᵒC in all zones started from the first floor to the seventh floor. It was 31.45ᵒC in the eight floor. The temperature inside the shaft was 22-25ᵒC. The velocity was ranged between 0.09-0.61m/s, as shown in Figure (5.47). Air movement was noticed inside the shafts especially in the northern ones. The pressure was -278 Pa. As shown in Figure (5.48), LMA tool calculated the AA inside zones, for example, the fifth floor. The max AA in zone L5-SE was 2000 sec (33 min). The max AA in zone L5-SW was 1093 sec (18.20 min). The max AA in zone L5-NE was 1924 sec (32.07 min). The max AA in zone L5-NW was 1399 sec (23.32 min).

Figure (5.45): Systematic concept of WC2

Source: http://keywordsuggest.org/gallery/647630.html

141

SW NW SE NE

Figure (5.46): Longitudinal sections of the wind catcher pattern 02

a. southern zones b. northern zones

Figure (5.47): Air velocity inside the main shafts of WC2

a. Southern zones, SE, & SW b. northern zones, NE, & NW

Figure (5.48): AA inside the fifth-floor zones in case of WC2

142

Discussion: When wind blows over the windcatcher, it creates lower air pressure on the windward side. Since the air pressure inside the building is higher than the outside, the tendency of higher pressure air traveling to the lower pressure region causes the air to be drawn upwards (Mourad et al., 2014). In case of WC1, the air pressure inside the zones was low pressure. This made the air corridor inside the building. The effect appeared in the southern zones. In case of WC2, by using cooling pads, the air temperature decreased inside the shafts. This raised the pressure therefore, the air displacement occurred especially in the western zones i.e. NW, and SW. the effect was less in the eastern zones, especially near the stair shaft. Kohta Ueno et al. (2012) suggested using an air barrier compartmentalization concept. Each unit is isolated from adjacent units and from the exterior by an air barrier system with a maximum air leakage rate of 2.0 L/(s∙m2) at 75 Pa. so, it is recommended in the study to use wind catcher with cooling pad for western zones, and using an air barrier compartmentalization concept in the eastern zones, as shown in Figure (5.49).

Figure (5.49): an air barrier compartmentalization concept

Source: (Kohta Ueno et al., 2012)

5.1.5.2 Skylight glazing The concept here inspired from the principle of the solar chimney, as shown in Figure (5.50). It aims to heat up the air inside the shafts. Natural ventilation setpoint was 25ᵒC. DesignBuilder manages to define natural ventilation setpoint to be below cooling temperature setpoint about 2 degrees. The AT was controlled by calculated natural ventilation. The glazing skylight stood up the last roof. Its shape was pyramidal glazing that stood on glazing nick, the supporting structure was steel. CFD boundary

143

conditions were adjusted depending on the summer week design in DesignBuilder V5. CFD simulation showed that the temperature was ranged between 28.41-36.36 ᵒC, as shown in Figure (5.51). The velocity was ranged between 0.08-0.56m/s. As shown in Figure (5.52), the pressure was -1.05 Pa. As shown in Figure (5.53), LMA tool calculated the AA inside zones, for example, the fifth floor. The max AA in the northern zones was 2578 sec (1h). while max AA in the southern zones was 2002 sec (33min). One can see the idea is more benefit in the southern zones.

Figure (5.50): Glazing skylight installed to upper opening of the main shafts

a. Temperature b. pressure Figure (5.51): Longitudinal sections of the glazing skylight

Figure (5.52): Air velocity inside the main shafts of glazing skylight

144

Figure (5.53): Age of air inside the fifth-floor zones in case of the glazing skylight

Discussion: It is concluded that the pressure inside the upper part of the ventilation shafts were low since the air temperature was raised wherever the air traveled upward. This versed the pressure system in the shafts. The origin pressure in such shafts always as shown in Figure (5.38). The ventilation shafts withdrew the air inside the zones since the air flows from the high pressure to the low pressure. Also, it raised the air velocity. The natural ventilation of the building was considered based on only buoyancy-driven natural ventilation induced by the heat gains from the solar radiation source (glazing skylight) present in the building (Hussain & Oosthuizen, 2012). The air stayed for a long time inside the zones. If SHDs were applied, they would make the zones colder, therefore, the pressure would be higher. Also, the air would be stay no long. The procedure appeared a response in the upper floors, but it created a high pressure region in the fifth floor level (middle zone). There were a need for driven force or wind induced (for exhausting system) that should couple with the skylight (Moosavi, Mahyuddin, Ab Ghafar, & Ismail, 2014). So, it is recommended in future buildings to open the slab in first floor. Also, microclimate plays a good chance to motivate and induce the air to move especially in the south direction.

5.1.5.3 DSF At first, Refereeing to section 5.1, double skin façade (DSF) already was used as a pattern of natural ventilation integrated with the buildings. Its mechanism is as same as the solar chimney. The aim was to heat up the air inside the cavity between the inner and outer layers of DSF. In turn, the air inside the cavity withdrew the indoor air from

145

the zones. The velocity was ranged between 0.03-0.09m/s, as shown in Figure (5.54). As shown in Figure (5.55), LMA tool calculated the AA inside zones, for example, the fifth floor. The max AA in zone L5-NE was 1064 sec (17.73 min). The max AA in zone L5-NW was 528 sec (8.8 min). The max AA in zone L5-SE was 600 sec (10 min). The max AA in zone L5-SW was 660 sec (16 min).

Figure (5.54): Air velocity inside the L5-SW of DSF case

SW NE

SE NE

Figure (5.55): AA inside the fifth-floor zones in case of DSF

146

5.1.5.4 DSFWC Referring to section 5.1, here explanations concentrated on AA. LMA tool calculated the AA inside zones, for example, the fifth floor. The max AA in zone L5- NE was 555 sec (9.25 min). The max AA in zone L5-NW was 855 sec (8.8 min). The max AA in zone L5-SE was 629 sec (10 min). The max AA in zone L5-SW was 623 sec (16 min), as shown in Figure (5.56). air velocity was between 0.02-0.14 m/s, as shown in Figure (5.57).

SW NW

SE NE

Figure (5.56): AA inside the fifth-floor zones in case of the DSFWC

Figure (5.57): Air velocity inside the fifth-floor zones in case of the DSFWC

147

Figure (5.58): Air velocity inside the fifth floor zones in case of the DSFWC

Discussion: DSF achieved less air velocity inside the zones which required for indoor air quality. Two parameters are used in exploring the buoyancy force: the width of double-skin façade and the temperature of the skin façade. In general, double-skin façade of a high-rise building in tropical climate can generate buoyancy driven ventilation for the building, it relates strongly to the distance between of the double- skin façade and the building envelope (Aziiz & Koerniawan, 2017). If SHDs were installed inside the cavity of DSF, the effect would be astonishing. The addition of the wind-catcher (case ‘WC’) therefore appears to be the most efficient strategy (Spentzou et al., 2014). The area that air occupied for certain time was less than DSF alone. The volumetric air improved by using WC. Also, induced force increased the air replacement. So, it recommended in this study for multi-storey buildings to use DSF coupled with WC.

5.1.5.5 GDSF Referring to section 5.1, here explanations concentrated on AA. LMA tool calculated the AA inside zones, for example, the fifth floor. The max AA in zone L5- NE was 809 sec (9.25 min). The max AA in zone L5-NW was 493 sec (8.8 min). The max AA in zone L5-SE was 484 sec (10 min). The max AA in zone L5-SW was 828 sec (16 min), as shown in Figure (5.59). If WC was integrated, the max AA in zone L5-NE was 855 sec (9.25 min). The max AA in zone L5-NW was 555 sec (8.8 min). The max AA in zone L5-SE was 629 sec (10 min). The max AA in zone L5-SW was 623 sec (16 min).

148

SW NW

SE NE

Figure (5.59): Age of air inside the fifth-floor zones in case of the GDSF

a. GDSF b. GDSFWC

Figure (5.60): Air velocity inside the L5-SW of GDSF, and GDSFWC scenarios

Figure (5.61): Air velocity inside the fifth-floor zones in case of the GDSF

149

Discussion: AA can help us to decide which strategy could be more beneficial, especially in the context of natural ventilation. Calautit and Hughes (2014) clarified that the numerical analysis of the AA allowed to detect less or insufficient ventilated areas. As shown in Table (5.1), max of AA was ranged between 16-23.75 min in the examined zones by using SHDsWC1. While it was ranged between 18.22-30.38 min by using

SHDsWC2, Likely, (Gilani, Montazeri, & Blocken, 2016). In case of glazing skylight, max of AA was ranged between 5.17-39.04 min. Acred and Hunt (2013) found a key result is that vent sizes must ascendingly increase in the building to compensate for the corresponding decrease in stack pressure available to drive flows through the upper storeys. However various studies have shown that in some cases the atrium can actually restrict flows through the building (Lynch & Hunt, 2011). As for the scenario of DSF, max of AA was ranged between 8.81-17.73 min. When Dardir (2012) studied the performance of DSF in presence of installing sun breakers, he found that the max AA was 4 min. If WC was integrated with the previous scenario, max of AA will be ranged between 9.27-12.97 min. In case of GDSF, max of AA was ranged between 6.72-12.56 min. Rivera (2014) achieved AA that ranged from 0-60 minutes by using VGS. However, Indoor air quality is a good indicator of a healthy building environment, as it evaluates how indoor air affects the health and comfort of building occupants. Although SHDs and SHDsWC declined the AT about 4 ᵒC in the examined zones, the greatest values of AA were in case of SHDs and glazing skylight scenarios. Although GDSF inclined AT about 3ᵒC, the minimal value of AA was obtained. Also, air velocity values were the minimum, this agreed with (Santamouris & Kolokotsa, 2016). By selecting the GDSF with WC scenario, Figure (3.5) showed that the results were within the human comfort zone by 18%. If the internal heat gain was scheduled, the strategy would cover 51.4% of the human comfort zone. Taleb (2014) investigated using passive cooling strategies to improve thermal performance and reduce the energy consumption of residential buildings in U.A.E. buildings. The results were within the human comfort zone by 34.8%.

150

RC 40.00

GDSFWC 30.00 SHDsWC1 20.00 10.00 0.00 DSFWC SHDsWC2

DSF glazing skylight

age of air (Min) for L5 Figure (5.62): Age of air in fifth floor

Table (5.1): Air velocity versus age of air in fifth floor

air velocity age of air (Min) for L5 direction m/s NE 1.61 17.73 NW 0.80 8.81 RC 0.15-1.04 SE 0.91 10.01 SW 1.45 15.99 NE 1.59 17.50 NW 2.16 23.75 SHDsWC1 0.06-0.69 SE 1.63 17.95 SW 1.73 18.97 NE 2.92 29.17 NW 2.92 26.23 SHDsWC2 0.09-0.61 SE 3.04 30.38 SW 3.04 18.22 NE 15.63 39.07 glazing NW 31.25 35.00 0.08-0.56 skylight SE 12.13 30.33 SW 3.03 15.17 NE 1.61 17.73 NW 0.80 8.81 DSF 0.03-0.09 SE 0.91 10.01 SW 1.45 15.99 NE 1.30 12.97 NW 0.84 9.27 DSFWC 0.02-0.14 SE 0.95 10.49 SW 0.84 9.44 NE 1.23 12.26 NW 0.75 6.72 GDSFWC 0.03-0.09 SE 0.89 8.86 SW 1.28 12.56 5.1.5.6 Thermal mass flooring Referring to section 2.5.1, in this section will discuss the possibility of using thermal mass into a floor of QEAB. RC is using porcelain flooring; its thermal properties are shown in Table (appx 1.1). HVAC system was natural ventilation. Boundary conditions were adjusted both of 12pm, and midnight of 1-Aug. Stone was used as the thermal mass material into the floor of L8-SW. Its position was, as shown in Figure (5.63). According to PEC, its density is 2250 kg/m3. Its specific heat is

151

1000J/kg.k. Its conductivity is 1.7 W/m.k. Air velocity was 0.14-0.16 m/s. AT was 33.12ᵒC at 12pm. while it was 29.99-31.11 at midnight. The lowest temperature was near to windows, as shown in Figure (5.64). By implementing thermal mass, AT was 29.75-31.77C at 12pm, while it was 31.09, as shown in Figure (5.65). Air velocity was 0.08-0.34m/s, as shown in Figure (5.66). The effect was clearly found in daylight, which the AT declined 3ᵒC at 12pm in spite of the night was slightly differed. Air velocity was at nighttime 0.13-0.16 in the lowest part of the zone. But it was 0.15 at the upper part. While at 12 pm when the sun is shining, 0.11-14, as shown in Figure (5.66). It is knowable that AT has the positive relationship with air velocity.

Figure (5.63): Thermal mass position into L8-SW floor

a. At 12pm b. at midnight

c. At 12pm d. at midnight Figure (5.64): AT and air velocity of RC of L8-SW

152

a. At 12pm b. at midnight

c. At 12pm d. at midnight Figure (5.65): AT and air velocity of thermal mass of L8-SW

12pm 24 Figure (5.66): Air velocity of L8-SW (thermal mass case)

porcelain stone Figure (5.67): Surface temperature of porcelain and stone

As shown in Figure (5.67), porcelain, has a temperature of the internal surface above 32ᵒC which is higher than the temperature of external surface. But, in case of stone, the internal and the external surface was almost the same. Arcuri, Carpino, and De Simone (2016) clarified that the surface temperatures of the building components reach values close to the air temperature, this results in greater energy stored. So, it is recommended for NZEBs to use passive strategies as well as thermal mass especially in the upper floors.

153

5.2 Mechanical ventilation (MechVent)

In this section, the calculations of mechanical ventilation depended on the criteria of the previous sections. Load components relied on the exaggeration assumption of using appliance and occupation, as shown in Table (3.2). In case of both the mechanical ventilation, SC should be limited to 0.7-0.5, referring to Figure (4.18). Comfort band was 19-27ᵒC. Steady-state design in DesignBuilder V5 has been concentrated. The procedure would depend on three strategies. These strategies were shading devices SHDs, double skin façade (DSF), and the combination of DSF and vertical greenery system (GDSF). Table (5.2): MechVent annual loads of RC for the examined zones

zone ACL (MWh) AHL (MWh) NE 5.44 2.06 NW 5.69 1.56 SE 6.02 1.49 SW 6.34 1.1 5.2.1 Shading devices SHDs This section intended to install SHDs on windows using SC of 0.6-0.5. SHDs were 0.5OH plus SFs, as shown in Table (appx 1.2). Generally, the results showed that cooling and heating loads were minimized. The majority of the heat loss flow through walls and glazing. Also, it occurred due to an external infiltration which it unintended air that entered the zone through cracks especially that airtightness was not taken into the consideration. - As shown in Figure (5.68a), ACL declined about 28.71, 32, 33.35, and 36.87% in zones NE, NW, SE, and SW respectively. AHL declined about 16.48% in zone NE. while it increased about 8.13, 5.96, and 30.23 in zones NW, SE, and SW respectively. ALs if they were compared with RC, they declined about 25.35, 23.20, 25.47, and 25.03% in zones NE, NW, SE and SW respectively. The behavior of AL in the examined zones was as shown in Figure (5.68b).

154

8.00 RC-ACL RC-AHL SHDs-ACL SHDs-AHL 6.00 1.00

4.00 0.50 MWh 2.00 0.00 0.00

-0.50 MWh

-1.00

RC-ACL

RC-AHL SHDs-ACL SHDs-AHL -1.50 NE NW SE SW -2.00 MechVent-NE

a. MechVent annual loads b. typical behavior of AL

Figure (5.68): MechVent loads and their behavior of the examined zones (SHDs scenario)

On the other hands, the results showed that AVs of SHGw, HLg, HLw, HLif declined in the examined zones: NE, NW, SE, and SW, as follows:

- As shown in Figure (5.69a), AV of SHGw declined about 64.24, 75.06, 69.95 and 76.69% respectively. AV of HLg declined about 34.33, 37.43, 36.57, and 38.84%. AV of HLw declined about 12.95, 28.32, 28.43, and 38.34% respectively. AV of

HLif declined about 39.35, 43.52, 43.61, and 47.23% respectively.

- As shown in Figure (5.70), Dc were 6128.00, 6117.00, 6015.50, and 6010.50 hours in zones NE, NW, SE, and SW respectively. Occupants experienced 70, 64, 65, and 61% discomfort against 30, 36, 35, and 39% comfort hours throughout the year.

15.00 10.00 5.00

MWh 0.00 -5.00 -10.00 RC SHG RC SHG RC SHG RC SHG NE NW SE SW

HLg HLw Hlif SHG

a. HL through the envelope b. the behavior of HL

Figure (5.69): HLG the examined zones (SHDs)

155

8760.00

4380.00 hours 0.00 RC SHG RC SHG RC SHG RC SHG

NE NW SE SW

Figure (5.70): Dc of the examined zones (SHDs)

Discussion: as mentioned before in section 5.1.1. SHDs were able to mitigate the AT inside the examined zones. To withhold the sun from both of walls and windows, energy savings could take place. SHDs were success in preventing the SHG through the windows in summer, but their results were not satisfied in winter. DB considered windows were not opened whenever the HVAC system worked. However, the effect of preventing SHG was clearly appeared on AL which declined by around 25%. But, it can be more effective by using a well-designed window, instead of using shading devices stand alone. The recent solutions connect the SHDs with controller system that depends on thermal comfort setpoint. As well as, Atzeri, Pernigotto, Cappelletti, Gasparella, and Tzempelikos (2013) analyzed the effect of the windows shading systems both on visual and thermal comfort and on the total building energy needs (for heating, cooling and artificial lighting). In the context of NZEB, the comfort level is required. So, it is recommended to connect the HVAC system with thermal comfort controller.

5.2.2 Double skin façade DSF This section displays the effect of DSF on mechanical ventilation loads. The idea was the same as the specifications that are explained in category 5.1.3, as shown in Figure (5.15). But, airtightness was not taken into the consideration. The results showed that: As shown in Figure (5.71a), ACL declined about 4.48, 4.40, 4.70, and 5.61% in zones NE, NW, SE, and SW respectively. AHL declined about 70.60, 77.62, 79.36, and 85.34% in zones NE, NW, SE, and SW respectively. ALs if they were compared with RC, they declined about 22.64, 20.17, 19.52, and 17.39% in zones NE, NW, SE and SW respectively. The behavior of AL in the examined zones was as shown in Figure (5.71b).

156

RC-ACL RC-AHL DSF-ACL DSF-AHL 10.00 1.00

MWh 5.00 0.00 MWh 0.00 -1.00 RC-ACL DSF-ACL RC-AHL DSF-AHL

NE NW SE SW -2.00 MechVent-NE

a. MechVent annual loads b. typical behavior of AL

Figure (5.71): MechVent loads and their behavior of the examined zones (DSF scenario)

Also, the results showed also that AVs of SHGw, HLg, HLw, and HLif declined in the examined zones: NE, NW, SE, and SW, as follows:

- As shown in Figure (5.72a), AV of SHGw declined about 79.37, 74.28, 69.81 and 67.49% respectively. AV of HLg declined about 59.62, 71.76, 69.44, and 81.04 respectively. AV of HLw increased about 12.93, 15.52, 14.36, and 16.96%

respectively. AV of HLif declined about 97.85%. HLp appeared in the scenario of DSF, it increased to 0.66, 0.56, 1.17, and 1.11 MWh in NE, NW, SE, and SW respectively.

On the other hands, the results showed that: As shown in Figure (5.73), Dc were 5828.50, 5540.00, 5598.50, and 5642.50 hours in zones NE, NW, SE, and SW respectively. Occupants experienced 67, 63, 64, and 64% discomfort against 33, 37, 36, and 36% comfort hours throughout the year.

15.00 10.00 5.00

MWh 0.00 -5.00 -10.00 RC DSF RC DSF RC DSF RC DSF NE NW SE SW

HLg HLw Hlif SHG

a. HL through the envelope b. the behavior of HL

Figure (5.72): HLG the examined zones (DSF)

157

8760.00

4380.00

0.00 RC DSF RC DSF RC DSF RC DSF

NE NW SE SW

Figure (5.73): Dc the examined zones (DSF)

Discussion: DSF has a magnificence role in the architectural appearance. Most authors used it in the context of natural ventilation. However, DSF windows closed in presence of using mechanical ventilation. The significant effect was on heating loads. DSF blocked the sun from the inner layer of DSF although there was a magnitude of SHG. Parra, Guardo, Egusquiza, and Alavedra (2015) investigated using louvers at proximity to the exterior skin of the façade that can notably affect the thermal performance of the DSF and hence the heat gains experienced by the building. Also, it could reduce the heat loss through the glass and vents. Heat loss through walls appeared because of overcast and nights times in winter. The results showed that there were a need for more sun blocking. To get an efficient envelope, it is recommended to install SHDs in between DSF layers.

5.2.3 GDSF This section displays the effect of the combination of double skin façade DSF and vertical greenery system (GDSF) on the mechanical ventilation loads. The idea was the same as the specifications that are explained in category 5.1.4, as shown in Figure (5.26). But, airtightness was not taken into consideration. The results showed that: - As shown in Figure (5.74a), ACL declined about 18.37, 19.54, 20.19, and 22.63% in zones NE, NW, SE, and SW respectively. AHL declined about 68.05, 68.69, 71.32, and 72.16% in zones NE, NW, SE, and SW respectively. ALs if they were compared with RC, they declined about 32.02, 30.13, 30.34, and 29.94% in zones NE, NW, SE and SW respectively. The behavior of AL in the examined zones was as shown in Figure (5.74b).

158

RC-ACL RC-AHL DSFGDSF-ACL DSFGDSF-AHL 8.00 1.00 6.00 4.00 MWh 2.00 0.00 0.00

MWh -1.00

RC-ACL

RC-AHL

GDSF-ACL GDSF-AHL

-2.00 NE NW SE SW MechVent-NE b. MechVent annual loads b. typical behavior of AL

Figure (5.74): MechVent loads and their behavior of the examined zones (GDSF scenario)

On the other hands, the results showed that AVs of SHGw, HLg, HLw, and HLif declined in the examined zones: NE, NW, SE, and SW, as follows:

As shown in Figure (5.75a), AV of SHGw declined about 84.50, 81.07, 76.36 and 75.04% respectively. AV of HLg declined about 75.81, 82.18, 80.43, and 87%. While

AV of HLw increased about 2.89, 2.09, 1.51, and 1.87% respectively. AV of HLif declined about 97.93, 97.98, 97.98, and 98.03 % respectively. Also, HLp appeared in the scenario of GDSF, it increased to 0.37, 0.24, 0.60, and 0.5 MWh in NE, NW, SE, and SW respectively. On the other hands, as shown in Figure (5.76), Dc were 5841.50, 5596.00, 5564.00, and 5471.00 hours in zones NE, NW, SE, and SW respectively. Occupants experienced 67, 64, 64, and 62% discomfort against 33, 36, 36, and 38% comfort hours throughout the year.

15.00 10.00 5.00

MWh 0.00 -5.00 -10.00 RC GDSF RC GDSF RC GDSF RC GDSF NE NW SE SW

HLg HLw Hlif SHG

a. b. HL through the envelope b. the behavior of HL

Figure (5.75): HLG the examined zones (GDSF)

159

8760.00

4380.00

0.00 RC GDSF RC GDSF RC GDSF RC GDSF

NE NW SE SW

Figure (5.76): Dc the examined zones (GDSF)

Discussion: using plantation and evaporative methods are helpful in reducing the heat that transfers to the building. As well as DSF, GDSF was able to block the solar radiation. But, GDSF was successful to reduce the cooling loads rather than DSF. The provision of humidity and evaporation achieved a good level of the indoor thermal comfort. Because of the VGS ,which provide the lower wind speed and higher humidity on microclimatic layer, acts as a wind barrier and verifies the effect of evapotranspiration from plants, reduced the energy consumption for cooling and heating of buildings (Jaafar, Said, Reba, & Rasidi, 2015). It is recommended for NZEB to use evaporative strategies to get indoor thermal comfort for occupants.

5.3 Mixed ventilation (MXM)

In fact, mixed mode ventilation is a common type of ventilation in Gaza. But in the other way, people manage to improve the comfort level of their spaces using AC unit whenever the electricity is available. Then, they are forced to use another means to mitigate indoor temperature as well as chargeable fans or any primitive means in case of shortage of electricity. In this study, comfort band was in between of 19-27ᵒC. Table (5.3) shows the annual cooling load (ACL) and heating load (AHL) for RC of the examined cases. Airtightness was taken into consideration using good crack template that is built in DesignBuilder. Also, the thermal break was installed to windows frames. On the other hand, discomfort hours -the time when the zone is occupied that the combination of humidity ratio and the operative temperature is not in the ASHRAE 55-2004 summer or winter clothes region- was observed. As well as natural ventilation, same strategies were implemented using SHDs, SHDsWC, DSF, DSFWC, GDSF, and GDSFWC.

160

Table (5.3): Mixed HVAC loads for RC

zone ACL (MWh) AHL (MWh) NE 4.78 1.15 NW 4.99 0.896 SE 5.34 0.650 SW 5.67 0.576 5.3.1 Shading devices SHDs By applying SHDs on the elevations wherever there were windows, the thermal behavior of the zones changed. Taking into consideration that SC was below 0.5-0.4, as shown in Figure (4.19). Generally, ACLs declined, AHLs increased. The results showed that: - As shown in Figure (5.77a), ACL declined about 48.40, 49.43, 52.75, and 53.87% in zones NE, NW, SE, and SW respectively. AHL increased about 43.09, 61.30, 64.62, and 74.13% in zones NE, NW, SE, and SW respectively. ALs if they were compared with RC, they declined about 24.31, 17.80, 27.22, and 22.46% in zones NE, NW, SE and SW respectively. The behavior of AL in the examined zones was as shown in Figure (5.77b).

6.00 RC-ACL RC-AHL SHDs-ACL SHDs-AHL 5.00 1.00 4.00 0.50

3.00 MWh 2.00 0.00 1.00

0.00 -0.50 MWh

-1.00 RC-ACL

RC-AHL -1.50

SHDs-ACL SHDs-AHL NE NW SE SW -2.00 MXM-NE a. MechVent annual loads b. typical behavior of AL

Figure (5.77): MXM loads and their behavior of the examined zones (SHDs scenario)

Also, the results showed that AVs of SHGw, HLg, HLw, and HLif in the examined zones: NE, NW, SE, and SW, were as follows: As shown in Figure (5.78a), AV of SHGw declined about 64.24, 75.06, 69.95 and 76.69% respectively. AV of HLg declined about 60.00, 62.50, 62.00, and 62.92% respectively. AV of HLw increased about 2.89, 2.09, 1.51, and 1.87% respectively. AV of HLif increased about 24.64, 13.11, 14.02, and 4.90 % respectively. On the other

161

hands, as shown in Figure (5.79), the results showed that Dc were 6491.50, 6506.50, 6424.50, and 6430.50 hours in zones NE, NW, SE, and SW respectively. Occupants experienced 74, 74, 73, and 73% discomfort against 26, 26, 27, and 27% comfort hours throughout the year.

15.00 10.00

5.00 MWh 0.00 -5.00 -10.00 RC DSF RC DSF RC DSF RC DSF NE NW SE SW

HLg HLw Hlif SHG

a. HL through the envelope b. the behavior of HL

Figure (5.78): HLG through the envelope of the examined zones (SHDs)

8760.00

4380.00

hours 0.00 RC SHDs RC SHDs RC SHDs RC SHDs

NE NW SE SW

Figure (5.79): Dc of the examined zones (SHDs)

In case of implementing shading devices in addition to wind catcher (SHDsWC), as shown in Figure (5.10), the results showed that: - As shown in Figure (5.80a), ACL declined about 49.52, 48.20, 53.78, and 55.04% in zones NE, NW, SE, and SW respectively. AHL increased about 51.85, 67.31, 70.63, and 78.61% in zones NE, NW, SE, and SW respectively. ALs if they were compared with RC, they declined about 19.00, 9.52, 21.87, and 16.04% in zones NE, NW, SE and SW respectively. The behavior of AL in the examined zones was as shown in Figure (5.80b).

162

Also, the results showed that AVs of SHGw, HLg, HLw, and HLif in the examined zones: NE, NW, SE, and SW, were as follows: As shown in Figure (5.81a), AV of

SHGw declined about 64.27, 75.07, 70.04 and 76.74% respectively. AV of HLg declined about 64.94, 66.41, 66.76, and 67.70% respectively. AV of HLw decreased about 70.37, 80.76, 79.65, and 84.48% respectively. AV of HLif increased about 31.87, 20.20, 21.45, and 14.48 %. 6.00 5.00 RC-ACL RC-AHL SHDsWC-ACL SHDsWC-AHL 4.00 3.00 1.00

MWh 2.00 1.00 0.50 0.00 0.00

MWh -0.50

RC-ACL RC-AHL

-1.00 SHDsWC-ACL SHDsWC-AHL -1.50 NE NW SE SW -2.00 MXM a. MXM annual loads b. typical behavior of AL

Figure (5.80): MechVent loads and their behavior of the examined zones (SHDsWC)

HLg HLw Hlif SHG 15.00 10.00 5.00 0.00

MWh -5.00 -10.00

-15.00

RC RC RC RC

SHDsWC SHDsWC SHDsWC SHDsWC NE NW SE SW

a. HL through the envelope b. the behavior of HL

Figure (5.81): HLG through the envelope of the examined zones (SHDsWC)

Besides, the results showed that Dc were 6593.00, 6589.00, 6508.0,0 and 6523.00 hours in zones NE, NW, SE, and SW respectively. Occupants experienced 75, 75, 74, and 74% discomfort against 25, 25, 26, and 26% comfort hours throughout the year, as shown in Figure (5.82).

163

8760.00

4380.00 hours

0.00

RC RC RC

SHDsWC SHDsWC SHDsWC SHDsWC NE NW SE SW

Figure (5.82): Dc of the examined zones (SHDsWC)

Discussion: In addition to discussion of section 5.1.1, SHDs could be used as a passive strategy that it help to reduce the energy consumption especially in summer. A well shading design means to invent a dual mechanism for ventilation and reduce heat transfer to the space simultaneously. Cheong, Kim, and Leigh (2014) implemented double window system. This concept was using shading devices installed in the intermediate cavity between the external and internal windows. Solar radiation is blocked by the shading device, and any heat absorbed by the shade can be exhausted outdoors by ventilating the cavity space. The HVAC reduction was about 43%–61%. So, in the context of NZEBs, it is beneficial to use dual goals in one concept to get an efficiency envelope. On the other hand, SHDs could couple with WC, the approach reduced the heat loss through walls and glazing. The heat loss through infiltration appeared because of the induced air that forced from WC which took place wherever the air displacement could take a part. Huang, Liu, and Liang (2015) proposed a novel design of buoyancy driven dynamic shading system. The design processes are composed of three parts: an alterable angle of blind slats that raises the energy performance to be suitable for every orientation, the buoyancy driven transmission mechanism, and a humanized controller that ensures its convenience. Also, (Hien & Istiadji, 2003) used SHDs as a wind catcher. They confirmed that vertical shading devices were not effective in enhancing daylighting and natural ventilation. So, it recommended to use an automated horizontal components of SHDs or using ventilated double window system for mixed ventilation.

164

5.3.2 Double skin façade DSF DSF configrations for QEAB was explained before in categorey 5.1.3, as shown in Figure (5.15). Here, HVAC system was mixed mode ventilation (MXM). Generally, cooling loads increased, heating loads decreased. The results showed that: - As shown in Figure (5.83a), ACL increased about 3.30, 13.45, and 2.00% in zones NE, NW, and SE respectively. While it inclined about 1.68% in zone SW. AHL declined about 48.83, 39.76, 59.02, and 63.03% in zones NE, NW, SE, and SW respectively. ALs if they were compared with RC, they declined about 6.72, 4.57, and 7.33% in zones NE, SE and SW respectively. While it increased about 6.65% in zone NW. The behavior of AL in the examined zones was as shown in Figure (5.83b).

RC-ACL RC-AHL DSF-ACL DSF-AHL 10.00 1.00

5.00 MWh 0.00 0.00

-1.00

MWh

RC-ACL

RC-AHL

DSF-ACL DSF-AHL NE NW SE SW -2.00 MXM-NE a. MXM annual loads b. typical behavior of AL

Figure (5.83): MXM loads and their behavior of the examined zones (DSF scenario)

Also, the results showed that AVs of SHGw, HLg, HLw, and HLif in the examined zones: NE, NW, SE, and SW, were as follows: As shown in Figure (5.84a), AV of

SHGw declined about 79.37, 74.28, 69.81 and 67.49% respectively. AV of HLg declined about 69.85, 75.07, 73.31, and 78.59% respectively. AV of HLw decreased about 14.16, 9.90, 10.35, and 7.00% respectively. AV of HLif decreased about 63.66, 66.55, 65.66, and 66.66 % respectively. While AV of HLp increased about 60.42, 142.80, 74.96, and 125% respectively. On the other hand, as shown in Figure (5.85), Dc were 5072.50, 4594.50, 4344.00, and 4369.50 hours in zones NE, NW, SE, and SW respectively. Occupants experienced 58, 52, 50 and 50% discomfort against 42, 48, 50, and 50% comfort hours throughout the year.

165

15.00 10.00 5.00

MWh 0.00 -5.00 -10.00 RC DSF RC DSF RC DSF RC DSF NE NW SE SW

HLg HLw Hlif SHG

a. HL through the envelope b. the behavior of HL

Figure (5.84): HLG through the envelope of the examined zones (DSF)

8760.00

hours 4380.00

0.00 RC DSF RC DSF RC DSF RC DSF NE NW SE SW Figure (5.85): Dc of the examined zones (DSF)

The combination of DSF with wind catcher WC was applied to QEAB, as shown in Figure (5.10). The results showed many issues that differed about implementing DSF only in case of MXM ventilation. They showed that: As shown in Figure (5.86a), ACL inclined about 3.90, 4.01, and 6.12% in zones NE, SE, and SW respectively. While it increased about 10.50% in zone NW. AHL declined about 20.94, 3.72, 18.12, and 24.24% in zones NE, NW, SE, and SW respectively. ALs if they were compared with RC, they declined about 7.21, 5.54, and 7.79% in zones NE, SE and SW respectively. While it increased about 6.57% in zone NW. If windows opening was scheduled, the results showed: As shown in Figure (5.86b), ACL increased about 38.85, 45.50, 38.94 and 35.57% in zones NE, NW, SE, and SW respectively. Also, AHL increased about 48.12, 58.84, 59.75, and 59.97% in zones NE, NW, SE, and SW respectively. ALs if they were compared with RC, they increased about 40.90, 48.06, 42.18, and 39.00% in zones NE, NW, SE and SW respectively.

166

8.00 8.00 6.00 6.00

4.00 4.00

MWh MWh 2.00 2.00

0.00 0.00

RC-ACL

RC-AHL

RC-ACL

RC-AHL

ACL

DSFWCSCH

DSFWC-ACL

DSFWC-AHL DSFWCSCH- NE NW SE SW NE NW SE SW

a. MXM annual loads of DSFWC b. ALs loads of DSFWCSCH Figure (5.86): MechVent loads and their behavior of the examined zones (DSFWC scenario)

Also, the results showed that AVs of SHGw, HLg, HLw, and HLif in the examined zones: NE, NW, SE, and SW, were as follows: As shown in Figure (5.87a), AV of

SHGw was approximately the same as SHG of DSF alone. AV of HLg declined about 78.20, 83.34, 82.58, and 88.02% respectively. AV of HLw decreased about 33.00,

28.09, 28.73, and 24.14% respectively. AV of HLif increased about 11.00, 0.50, 8.60, and 4.91 % respectively. AV of HLp increased about 68.02, 134.39, 79.00, and 121.86% respectively. If windows opening was scheduled, the results showed: as shown in Figure (5.87b), AV of SHGw was approximately as same as SHG of DSF alone. AV of HLg declined about 80.29, 85.99, 85.71, and 91.82% respectively. AV of HLw decreased about 36.00, 31.66, 33.58, and 29.31% respectively. AV of HLif decreased about 2.52, 12.73, 4.59, and 9.14 % respectively. AV of HLp increased about 69.14, 131.68, 79.75, and 120.28% respectively. On the other hand, as shown in Figure (5.88a), Dc were 5395.00, 4897.00, 4628.00, and 4307.50 hours in zones NE, NW, SE, and SW respectively. Occupants experienced 62, 56, 53, and 49% discomfort against 38, 44, 47, and 51% comfort hours throughout the year. As for the windows opening scheduled, Dc were 3604.50, 3249.50, 3155.50, and 3052.00 hours in zones NE, NW, SE, and SW respectively. Occupants experienced 41, 37, 36, and 35% discomfort against 59, 63, 64, and 65% comfort hours throughout the year, as shown in Figure (5.88b).

167

10.00 10.00 5.00 5.00

0.00 0.00 MWh MWh -5.00 -5.00 -10.00

-10.00

RC RC RC RC

DSFWC DSFWC DSFWC DSFWC

DSFWCSCH DSFWCSCH DSFWCSCH DSFWCSCH NE NW SE SW NE NW SE SW HLg HLw Hlif SHG HLg HLw Hlif SHG

a. HLG of DSFWC b. HLG of DSFWCSCH Figure (5.87): HLG through the envelope of the examined zones (DSFWC)

8760.00 8760.00

4380.00

4380.00 hours hours 0.00

0.00

RC RC RC RC

RC RC RC

DSFWC DSFWC DSFWC

DSFWC

DSFWCSCH DSFWCSCH DSFWCSCH NE NW SE SW DSFWCSCH NE NW SE SW Figure (5.88): Dc of the examined zones (DSFWC)

Discussion: In addition to what mentioned in the section 5.1.3, if the vents scheduled, the air conditioning loads would increase. Not only DSFWC.SCH achieved less level of thermal comfort, but also it consumed more energy for cooling and heating space. The air in the cavity removes excess heat by means of convective flow that induced by the stack effect. This action prevents excessive heat accumulation in the cavity. If this occurs, unwanted heat can transmit into the internal spaces. This can have a significant impact on the thermal comfort conditions within the building and create a greater necessity for the use of auxiliary cooling systems, hence resulting in an increase in energy consumption. When the air is cleared from within the cavity, the temperature of the building envelope skin is lowered and heat transfer from the internal skin to the occupied space is reduced. Accordingly less heat is transferred from the outside to the inside, and less energy is required to cool the space (Kinnane & Prendergast, 2014).

168

5.3.3 GDSF GDSF idea was explained before in categorey 5.1.4, as shown in Figure (5.26). HVAC System was mixed mode ventilation (MXM). - As shown in Figure (5.89a), ACL inclined about 4.46, 10.05, and 13.76% in zones NE, SE and SW respectively. While it increased about 1.20% in zone NW. AHL declined about 54.03, 36.08, 48.92, and 46.32% in zones NE, NW, SE, and SW respectively. ALs if they were compared with RC, they declined about 14.08, 4.46, 14.26 and 16.76% in zones NE, NW, SE and SW respectively. In case WC incorporated to GDSF scenario, the results showed that: ACL inclined about 14.02, 3.99, 18.16, and 20.37% in zones NE, SE and SW respectively. AHL declined about 27.72, and 7.10 in zones NE, and SE respectively. While it increased about 1.42, and 1.17 in zones NW, and SW respectively. ALs if they were compared with RC, they declined about 16.68, 3.16, 16.96 and 18.39% in zones NE, NW, SE and SW respectively, as shown in Figure (5.89b).

- Also, the results showed that AVs of SHGw, HLg, HLw, and HLif in the examined zones: NE, NW, SE, and SW, were as follows: As shown in Figure (5.90a), AV of

SHGw declined about 84.50, 81.07, 76.36 and 75.04% respectively. AV of HLg declined about 80.93, 83.45, 82.10, and 85.04% respectively. AV of HLw

decreased about 17.67, 17.68, 17.91, and 16.82% respectively. AV of HLif decreased about 63.14, 66.73, 67.07, and 67.96 % respectively. AV of HLp increased about 18.92, 50.91, 48.44, and 61.70% respectively.

NE NW SE SW 6.00 NE NW SE SW 6.00

4.00 4.00 MWh

2.00 MWh 2.00 0.00 0.00

a. MXM loads of GDSF scenario b. MXM loads of GDSFWC scenario Figure (5.89): MXM loads of the examined zones (GDSF scenarios)

169

In case WC incorporated to the scenario of GDSF, the results showed that: AV of

SHGw was as same as implementing GDSF alone. AV of HLg declined about 88.95, 91.11, 90.47, and 93.43% respectively. AV of HLw decreased about 38.44, 37.02,

37.05, and 35.13% respectively. AV of HLif increased about 7.25% in zone NE. While it declined about 7.10, 1.13, and 6.52 % in zones NW, SE and SW respectively. AV of HLp increased about 46.33, 60.29, 61.21, and 69.77% respectively, as shown in Figure (5.90b), On the other hand, as shown in Figure (5.92a), Dc were 4991.50, 4677.50, 4360.00, and 4341.00 hours in zones NE, NW, SE, and SW respectively. Occupants experienced 57, 53, 50, and 50% discomfort against 43, 47, 50, and 50% comfort hours throughout the year. In case WC integrated to GDSF scenario, Dc were 5334.00, 5066.50, 4779.50, and 4558.00 hours in zones NE, NW, SE, and SW respectively. Occupants experienced 61, 58, 55, and 52% discomfort against 39, 42, 45, and 48% comfort hours throughout the year, as shown in Figure (5.92b).

10.00 10.00 HLg HLw Hlif SHG

5.00 5.00 MWh MWh 0.00 0.00 -5.00 -5.00

-10.00 -10.00

RC RC RC RC GDSF RC GDSF RC GDSF RC GDSF RC

NE NW SE SW

GDSFWC GDSFWC GDSFWC GDSFWC

HLg HLw Hlif SHG NE NW SE SW a. HLG of GDSF scenario b. MXM loads of GDSFWC scenario Figure (5.90): HLG of the examined zones (GDSF scenarios)

a. HLG of GDSF scenario b. HLG of GDSFWC scenario Figure (5.91): The behavior of HLG through the envelope of the examined zones (GDSF)

170

8760.00 8760.00

4380.00 4380.00

hours hours

0.00 0.00

RC RC RC RC

GDSF GDSF GDSF GDSF NE NW SE SW NE NW SE SW

Figure (5.92): Dc of the examined zones (GDSF)

Discussion: By using a new irrigation technologies and understanding the benefits of vegetation in double-skin façades, it is possible to get the energetic benefits resulting from implementation of a VGS (Prades Villanova, 2013). Green infrastructure can reduce surface and ambient temperatures at the micro-scale (Annie Hunter Block, Stephen J. Livesley, & Williams, 2012). GDSF could block the sun on the envelope surfaces. By using wind catcher, the indoor conditions improved. Also, WC reduced the heat loss through walls , glazing, and ventilation more than using GDSF alone. HL via vents increased due to driven force. Therfore, ALs minimized even though WC increased the annual heating loads. The effect was less on annual load of the zone NW due to proximate the sunset time (transpiration effect). So, it is strongly recommended for NZEBs to use a combined solution of plantiation and wind catcher. Summary: For NZEB, it is important to know which type of ventilation could save the energy. The impact of ventilation strategies on the energy performance of new and existing buildings located in the Mediterranean is a crucial issue to achieve the net-zero energy balance target (Grigoropoulos, Anastaselos, Nižetić, & Papadopoulos, 2017). Natural, mechanical, mixed HVAC systems were examined in presence of many scenarios of envelope retrofit process of QEAB. These scenarios are: 1) Shading devices SHDs. 2) Combination of SHDs with wind catcher (SHDsWC). 3) Double skin façade (DSF). 4) Combination of DSF and wind catcher DSFWC. 5) Combination of DSF, and vertical greenery systems (GDSF) and 6) combination of GDSF and wind catcher GDSFWC. Windcatcher was applied whenever the HVAC system was natural or of mixed mode. Natural ventilation was discussed in section 5.1. Taking into

171

consideration that windows will be closed in case of mechanical ventilation. The process took place with many criteria such as U-value, shading coefficient SC, wind direction, air tightness and discomfort hours. Also, an exaggeration assumption was fully occupancy. Beside, internal heat gain depeneded on tabulated information of CIBE for lighting and appliance, as shown in Table (3.2). Heat and loss graphs HGLG showed that cater process (cooking machines) has a significant role in heating up the zones. However, window solar gain and internal loads make up 60% of the total cooling load (Huang, Hanford, & Yang, 1999). Thus, the annual cooling load ACL and annual heating loads (AHL) and the total of these loads (AL) were as shown in Figure (appx 1.7) for zone NE, Figure (appx 1.8) for zone NW, Figure (appx 1.9): HVAC loads of zone SE) for zone SE, and Figure (appx 1.10) for zone SW. It should be remembered that the reference case (RC) is case 06, as shown in Table (4.1).  As for MechVent, SHDs scenario declined AL about 23.20-25.47% in the examined zones L5 (NE, NW, SE, and SW). This agrees with Grigoropoulos (2015) that showed that total annual energy consumption can be reduced by 23.6% usind shading devices as an effective ventilation strategy for net zero energy buildings in hot climates.  In turn MXM, SHDs scenario declined AL about 17.8-27.22 % in the examined zones. Brittle (2017) showed that the purpose of such device is to minimise solar heat gains without adversely affecting daylighting effects through the windows. Oh et al. (2017) showed that to realize nZEB, active strategies must be considered together with energy-saving techniques as passive strategies. As cited in Mirrahimi et al. (2016) In Malaysia, the results of a study indicated that the longer shading leads to the greater savings in both annual load and peak load. A horizontal shading device of 30 cm-deep between 2.62% and 3.24% helped in saving about5.85– 7.06% of the energy cooling load. Also, the cooling load could be saved by applying the depth of the window shading device of 60 cm.  In case of MecVent, DSF scenario, AL declined about 17.39-22.65%. The most efficient geometry was the multi-storey double-skin facade that presenting in average 30% less HVAC related energy demands (Alberto, Ramos, & Almeida, 2017).

172

 While in MXM, DSF scenario declined AL about 4.57-7.33%. (Aksamija, 2017) showed that in heating-dominated climates, cooling loads are significantly reduced (40-70%), while cooling-dominated climates have lower savings (25-40%). Pomponi and Piroozfar (2015) showed that in DSFs coupled with HVAC system and mixed ventilation of the cavity represent a further option to be considered and evaluated other than multi-storey geometry as this combination could offer higher performance of the DSF. Barbosa, Ip, and Southall (2015) showed that although the office building will still require other means of cooling during peak summer periods, the incorporation of DSF as part of a mixed-mode ventilation strategy can potentially have a significant impact on annual energy consumption.  Regarding the MechVent, GDSF scenario has an opportunity to save the energy in the building and consiquently AL declined about 30.13-32.02%. The more saved energy were the northern zones (NE, NW), as shown in Figure (5.93a). Hamid, Ono, Bostamam, and Ling (2015) presented a bioclimatic design using vertical greenery system (VGS) for building. The design refers to the temperature and humidity conditions that make human comfort and minimize energy consumption.  While in MXM, GDSF declined AL about 4.46-16.76%, AL of the NW zone had lowest energy saving. Oh et al. (2017) stated that GDSF can achieve 25% heating, and 10–30% cooling load reduction.

12.00 12.00 10.00 10.00 8.00 8.00 6.00 6.00 MWh 4.00

MWh 4.00 2.00 2.00 0.00

0.00

DSF

SHDs

GDSF

SHDs

GDSF

DSFWC

SHDsWC

GDSFWC

SHDsWC

GDSFWC

DSFWC.SCH DSFWC.SCH

NE NW SE SW NE NW SE SW

a. MechVent b. MXM Figure (5.93): AL of MechVent and MXM ventilation

In case of MXM, SHDsWC declined AL about 16.07-21.78%. In their point of veiw, Altan and Tabriz (n.d.) see that using wind catchers is beneficial during the night

173

when they lead to appropriate air flow and therefore to a reduction in indoor temperatures. During the day, even in a building without a wind catcher and with insulated envelope, using a mechanical cooling system just at noon and for some time in the afternoon is recommended. While DSFWC scenario declined AL about 5.54- 24.85 in case the windows opened for 24h. But, if they were scheduled, AL increased about 39-48.06. As well as DSF, GDSFWC scenario declined AL of RC about 3.16- 18.39%. The application of vertical shafts like atria, which bring daylight and natural ventilation deeper into the plan, are the strategies that effectively can provide energy savings for tall buildings (Raji, Tenpierik, & Van den Dobbelsteen, 2014). In contrary to the results of this study, Evins, Pointer, and Vaidyanathan (2011) presented a new approach to the optimization of DSFs. Parameters defined possible geometries, shading devices, openings and ventilation paths, as well as control schedules for their operation, whereas here it was successful at reducing cooling and heating loads. Now, the research can arrange the examined zones according to their AL, as shown in the Table (5.4). In case of mechVent, SHDs scenario approximately unioned annual loads. As for DSF scenario, annual loads of the northern zones were less than the annual loads of southern ones. As for GDSF scenario, the zones are arranged ascendingly according to their annual loads, they are: NW, NE, SW, and SE. In case of MXM, the zones are arranged ascendingly according to their annual loads as follows: 1- As for SHDs scenario, they are SE, NE, NW, and SW. 2- In case of SHDsWC scenario, they are SE, NE, SW, and NW. 3- In case of DSF scenario, they are NE, SE, SW, and NW. 4- As for DSF WC scenario, they are NE,SE,SW, and NW. 5- As for DSF WC.SCH scenario, they are NE, SW, SE, and NW. 6- In case of DSF GDSF scenario, they are NE, SE, SW, and NW. 7- In case of DSF, GDSF & WC scenario, they are NE, SE, SW, and NW.

174

Table (5.4): AL of mechanical and mixed mode HVAC

MechVent MXM

AL(MWh) AL (MWh) scenarios NE NW SE SW NE NW SE SW RC of C6 7.50 7.25 7.51 7.44 5.93 5.88 5.99 6.25 SHDs 5.60 5.57 5.59 5.58 4.49 4.84 4.36 4.85 SHDs WC 4.80 5.32 4.68 5.24 DSF 5.80 5.79 6.04 6.15 5.53 6.30 5.72 5.79 DSF WC 5.50 6.44 5.66 5.76 DSF WC.SCH 10.03 11.33 10.36 10.24 GDSF 5.10 5.06 5.23 5.21 5.10 5.62 5.14 5.20 GDSF WC 4.94 5.70 4.98 5.10

However, heat loss through glazing was less in case of MXM. DSF and GDSF combinations had less heat loss occured through the glazing, then SHDs, as shown in Figure (appx 1.11). Heat loss through walls was less in presence of MXM and WC. Then SHDs, SHDsWC, and DSF scenarios, as shown in Figure (appx 1.12). Heat loss through partitions were less in SHDs, DSF&GDSF, and DSF,GDSFWC scenario, as shown in Figure (appx 1.15). Heat loss through opening the internal windows for inner layer of DSF occurred less in presense of MXM and DSF, GDSF&WC, DSF WC.SCH, DSFWC, and DSF senarios, as shown in Figure (appx 1.14). Heat loss through infiltration through fabric were less in presence of mechanical HVAC and DSF, GDSF, and SHDs scenarios, as shown in Figure (appx 1.13). FAF occurred more in presence of MXM, and SHDsWC, as shown in Figure (appx 1.16). although DSF and GDSF considered as passive ventilation strategy, it used here as a thermal insulation in context of MechVent and MXM. In summer, the reduction of solar heat gain is the main effect of DSF, GDSF while in winter; they help to minimize the heat loss (GhaffarianHoseini, Berardi, GhaffarianHoseini, & Makaremi, 2012). Inspite of its higher annual loads, DSFWC.SCH scenario had less discomfort hours. Generally, discomfort hours were less in presence of DSF, DSFWC, GDSF and GDSFWC scnarios, as shown in Figure (appx 1.18). One can remmber that discomfort hours are the time when the combination of humidity ratio and operative temperature is not in the ASHRAE 55-2004 summer, winter or summer and winter clothes region. The IAQ specification is intended to support architects and contractors who pursue a

175

higher level of IAQ performance in net zero and other residential buildings (Bernheim, Hodgson, & Persily, 2015). The results can be summarized into the followings points:  Using SHDs effectively in the ventilation needs to a good management of shading and airflow altogether. Using ventilated double windows and others installed shading devices in between its pans can save energy. It is profitable for NZEBs to have controller system to manage the amount of sun entered to the space. Therefore, extra loads would be avoided whether in summer nights or in winter days in order to achieve high level of thermal comfort for occupants.  The effect of DSF is similarity to the SHDs in reducing the envelope areas to the sun. But, to be an effective DSF, two issues should be controlled: the width of double-skin façade itself and the temperature of the skin façade. The volume of DSF is a crucial element especially in residential multi storey compounds. Slim type double skin window can be used in buoyancy-driven natural ventilation. Also, installing shading devices within the cavity helps to reduce the temperature of the air inside the cavity that it will improve the air replacement inside the space.  Using plantation combined with WC proved its capability to improve the indoor air quality, in addition, get more energy savings.  Using CFD tool is beneficial to study the buoyancy-driven for natural ventilation. 1) Wind catcher coupled with earth tunnel or cooling pad installed inside the ventilation shafts can increase the air replacement rate inside the space. 2) Using glazing skylight should be coupled with ground microclimate by plantation and opening the slab in the ground slab level. 3) Using SHDs is beneficial if it coupled with DSF. 4) GDSF coupled with WC can decrease the internal air velocity which is required for thermal comfort. 4) Thermal mass charge and discharge process can reduce the AT even if the floor was the upper.

176

Chapter 6 RES generation and cost- effectivenees using PV panels

177

Chapter 6 RES generation and cost-effectiveness using PV panels

Introduction

Keeping in mind, Net zero energy comes up with the idea of exchanging surplus energy of what the building electricity produced to the utility. Notably, the energy should be produced by using renewable energy sources (RES). It seems like an investment between the owner and supplier. On the other hands, the potential of employing NZE in existing building become popular in order to reduce the consumption of energy that is used for either cooling or heating spaces which called NZE retrofit (NZER). Retrofits not only reduce operational energy but it plays a big role in other aspects of ecological, urban, social, equity and economic impacts (Zuhaib, Hajdukiewicz, Keane, & Goggins, 2016). This chapter is the answer to question no. five: What are the proposed scenarios of RES generation to get NZEB?

6.1 Renewable energy source generation RES

It is essential for NZE to generate the electricity using renewable energy sources RES. NZE depends on converting the building to a plant for generating the electricity. In this section, sensible heat gains ( room electricity) are due to lighting and appliance, as shown in Table (3.2) and domestic hot water energy consumption were treated as steady constant values assumption (exaggeration assumption) in QEAB. This was intended to get maximum end use of energy. The total energy consumption in the building was previously calculated using DesignBuilder, as shown in Table (3.1). The plenty of renewable sources that available in Gaza is solar radition. So, this section will discuss only using Photovoltaic (PV) in the energy generation in comparison with the main reference case and five proposal assumptions. Also, case 06 of envelope construction was selected to accomplish the comparing. These cumulative suggestions were: (1) BIPV, (2) BIPV-PV, (3) BIPV-PVA, (4) BIPV-PVP, (5) BIPV-PVGR). The HVAC system was mix mode ventilation. Energy consumption was calculated as shown in Table (appx 1.3), also, the electricity demands are shown in Figure (6.2) is

178

the sum of five components that consumed electricity annually in case of just using fuel to supply. These components are room electricity, lighting, heating load, cooling load, and domestic water. The characteristic forms of the five assumptions of PV generation were: 1. At first, photovoltaic models were integrated into the external envelope whether into opaque areas or into translucent areas to convert QEAB envelope to the building integrated photovoltaic BIPV. This was the first case. 2. Case 02, BIPV-PV, was in addition to the previous image of the envelope, indirect PV models were installed on the roof, as a footprint generation. Because of its function of water tanks for drinking and other occupants services, PV models were fixed to steel stands that were fixed to a height of 3 m in the northern side of the building, and on another side (southern side) was fixed to the height of 3.5. taking into consideration wind prevailing direction, as shown in Figure (6.1a).

3. Case 03, BIPV-PVA, it was similarity to case 02 except that aluminum 0.5 OHs shading devices were installed to the windows of all directions.

4. Case 04, BIPV-PVP, the Exception that PV models were built in the shading devices with the depth of projection 50cm, as shown in Figure (6.1b).

a. BIPV-PV case b. BIPV-PVP case

Figure (6.1): BIPV-PV and BIPV-PVP cases of RES generation

179

5. Case 05, (BIPV-PVGR), was building integrated Photovoltaic models with footprint PV, which was applying green roof technique -as shown in section 4.1.4 - to the roof of the building in addition to BIPV and footprint PV generation. Generally, In point of view of energy consumption, the total electricity demands declined in the five examined cases, as shown in Figure (6.3). In reality, reference case of QEAB consumed 524.72 Mwh. While applying case 06 to the external envelope construction, referring to Table (4.1), the total energy consumed in the building was 511.92 Mwh. As shown in Figure (6.2), two columns appeared. Blue columns point to the total amount of electricity demands at the building level in case of using the utility for supply, as mentioned before. While red columns indicate the amount of the energy that was generated by using photovoltaic models. In fact, DesignBuilder used to transform the amount of on-site generated energy into two parts. One could use for building electricity demands. Electricity demands would be covered by on-site generation and the rest would be offset by the utility. The other part of the transformation of on-site generation uses for a surplus that is going to the grid. In order to perform this step, we need to the special storage. this storage that has been elected was direct current (DC) with inverter alternative current (AC), as shown in Figure (2.21). Here the chance to invest in the utility will appear. Some countries manage to reward the owners who take care of applying net-zero energy to their buildings such as economic privileges or loans. Referring to Figure (6.2), and Table (appx 1.3) the on-site generated electricity of Case 01 of BIPV has covered 52.9% of electricity demands, Case 02 of BIPV-PV has covered 77.97% of electricity demands, Case 03 of BIPV-PVA has covered 71.27% of electricity demands, Case 04 of BIPV-PVP has covered 80.30% of electricity demands, and Case 05 of BIPV-PVGR has covered 71.44% of electricity demands. On the other hands, Table (appx 1.4) has explained electric loads satisfied for the five examined generation cases and so did Table (6.1) and Figure (6.3). The total on-site and utility electric sources TOSUES value was calculated to be 231.27 Mwh annually which related to the Total Electricity End Uses TEEU. Also, taking into consideration that Photovoltaic Power, and Power Conversion factor, total On-Site electric sources TOSES of the examined cases were calculated to be as follows:  BIPV case has generated 267.36 Mwh which it represents 115.6% of TOSUES.

180

 BIPV-PV case has generated 380.80 Mwh which represents 164.66% of TOSUES.

 BIPV-PVA case has generated 355.33 Mwh which represents 153.64% of TOSUES.

 BIPV-PVP case has generated 400.52 Mwh which represents 173.19% of TOSUES.

 BIPV-PVGR case has generated 355.39 Mwh which represents 153.67 % of TOSUES. Now we could look for the Net Electricity from Utility (NEU), according to Table (appx 1.4), and Table (6.1), it can be calculated by Equation (6.1): NEU = TOSUES – TOSES………………………………………………...……....…EQ (6.1) where, NEU: Net Electricity From Utility. TOSUES: Total On-Site and Utility Electric Sources. TOSES: Total On-Site Electric Sources. Besides, Surplus Electricity Going To Utility (SEGU) was calculated briefly in Table (6.1), and Figure (6.3), SEGU was 166.28Mwh for BIPV case which represents about 71.9% of TOSUES, it was 277.93Mwh for BIPV-PV case which represents about

120.18% of TOSUES, it was 253.22 Mwh for BIPV-PVA case which represents about

109.49 % of TOSUES, it was 297.44 Mwh for BIPV-PVP case which represents about

128.62% of TOSUES, and it was 253.28 Mwh for BIPV-PVGR case which represents about 109.52% of TOSUES. Also, Electricity Coming from Utility (ECU) has been calculated in Table (appx 1.4), also, Table (6.1), as shown in Equation (6.2): ECU = SEGU – NEU………………………………………………...………...…...…EQ (6.2)

Where, ECU: Electricity Coming from Utility, SEGU: Surplus Electricity Going to Utility, NEU: Net Electricity from Utility. Thus, ECU was 231.27 Mwh in the reference case. It was 231.15 Mwh in case of 06. It was 130.18 Mwh in case of BIPV. It was 128.40 Mwh in case of BIPV-PV. It was 129.16 Mwh in case of BIPV-PVA. It was 128.19 Mwh in case of BIPV-PVP.

Lastly, it was 129.16 Mwh in case of BIPV-PVGR.

181

600 400

200 MWh

BIPV

BIPV-

PVGR

ase

case 06 case

BIPV-PV

BIPV-PVA

BIPV+PVP BaseLineC

Electricity generation

Figure (6.2): PV generation results

Table (6.1): Electric loads satisfied of the examined generation cases

Electric Loads Satisfied Mwh

BaselineCa CASE 06 BIPV BIPV-PV BIPV-PV BIPV-PV BIPV-PV se A P GR

Total On-Site 0.00 0.00 267.36 380.80 355.33 400.52 355.39 Electric Sources Electricity Coming From 231.27 231.15 130.18 128.40 129.16 128.19 129.16 Utility Surplus Electricity Going 0.00 0.00 166.28 277.93 253.22 297.44 253.28 To Utility Net Electricity 231.27 231.15 -36.10 -149.54 -124.06 -169.26 -124.12 From Utility Total On-Site and Utility 231.27 231.15 231.27 231.27 231.27 231.27 231.27 Electric Sources

500.00 400.00 300.00 200.00

MWh 100.00 0.00 -100.00 -200.00 Total On-Site Electricity Coming Surplus Electricity Net Electricity Total On-Site and Electric Sources From Utility Going To Utility From Utility Utility Electric Sources

BaselineCase CASE 06 BIPV BIPV-PV BIPV-PVA BIPV+PVP BIPV-PVGR

Figure (6.3): Electric loads satisfied of the examined generation cases

The results showed that BIPV-PVP case achieved the higher chance of on-site electricity generating. Then BIPV-PV case, BIPV-PVGR, BIPV-PVA, and BIPV case.

182

But, if the occupancy and appliance operation were scheduled, we will get more opportunities to save energy and so will RES generation surplus. In fact, to get the total amount of consumed energy in the building, we need to the extra amount of the energy that should be used to bring the former one into a site which called net site energy. As shown in Table (appx 1.5). This value is affected by the coefficient of performance COP values. Figure (6.4) has displayed the total site energy and net site energy. Total site energy is the total gross energy consumed on site. Also, Net site energy is the net energy consumed on site (total site fuel consumption minus any on-site generation) (DesignBuilder V5).

BIPV-PVGR BIPV-PVP BIPV-PVA

BIPV-PV MWh BIPV CASE 06 BaselineCase 0.00 100.00 200.00 300.00 400.00 500.00 600.00 700.00

Net Site Energy Total Site Energy

Figure (6.4): Total site energy and net site energy of the examined generation cases

Disscussion:

The diminishing return of net site energy illustrates that the case BIPV-PVP achieved a large amount of on-site energy (optimum soluation). It annually produced 400.52 Mwh which account for 76% of the total site energy. In turn, net site energy was 141.77 Mwh. While in case of applying BIPV-PV, net site energy was 176.94 Mwh, and the on-site energy covered about 70% of the total site energy. Then, both of the cases of BIPV-PVA and BIPVGR were covered 68% of the total site energy. While applying just BIPV was covered 50% of the total site energy. Evola and Margani (2014) ,whose study is entitled to energy retrofit towards Net ZEB, proposed a technical solution in order to improve the energy performance of the Italian residential real estate, which built in 1950-1990, i.e. before the enforcement of specific

183

regulations about the reduction of energy consumption. The energy demand of the building was decreased from 157.3 to 84.8 kWh/ (m2 year), i.e. by about 46%. The annual electricity production needed from the PV system was 34.0 kWh/(m2 year). On other words, QEAB can produce 80% of its electricity demand. It produce 400.52MWh, while its elecricity demand is 498.76 MWh. The ‘use of renewable energy’ to ‘the total building electric demand’ ratio give a measure of the amount of renewable energy used for the building services: a high value means that a small amount of energy is required from the grid (Ascione et al., 2017). Ascione et al. (2017) provided a design and performance analysis of a zero-energy settlement in Greece. The generated energy from RES was 89% from the electricity demand for sector A and 92% for sector B. On the other hand, surplus energy that is going to utility means that the building generates at least as much energy as it uses in a year. The amount of surplus electricity was greater than the electricity coming from utility (Ascione et al., 2017). Thus, QEAB can produce 297.44MWh annually (24.79 MWh in a month) as a surplus energy. It was greater than the electricity coming from utility of about 57%. This should be credited. QEAB can invest in the grid with 12393.5 NIC (3521 USD) in a month. The cost of PV was estimated according to the basic form of renewable assessment in DB. The following PV prices were normalized to the area. In case of BIPV, the cost was 1184.3 USD per square meter. In case of BIPV-PV, BIPVA and BIPV-PVGR, the cost increased by 852 USD per square meter. In case of BIPVP, the cost increased by 2556 USD per square meter. Two features must be blended for any NZEB project: 100% producing energy from renewable energy sources, and 100% energy-efficiency measures. The former is prohibitive due to high cost and limited usable land area. The later not practical when there is a need for energy using equipment; which is a reality of modern society (Raffio et al., 2012). So, desirability, convenience, and cost are the three greatest barriers to adoption of deep energy retrofits (Rocky Mountain Institute, 2017).

184

6.2 Cost effectiveness

Cost-effectiveness is an important step toward achieving NZE. It is the ability to a trade-off between multi-objective elements that are related directly or indirectly to the diminishing of the energy consumption in the building and any factor that could affect net site energy. Taking into account that local industry materials are desired. The tool of optimization in DesignBuilder V5 have a capability to perform the step via Pareto front point. Pareto point is the point (optimal solution) that connected between many fuzzy objectives which are intended to select and to find their ability to achieve a net zero energy by their relationship with two main pillars. Our consideration here was about two pillars which were net site energy MWh and capital cost (CAPEX) GBP in order to achieve net-zero energy. The objectives were all the previous package energy measures that were mentioned before. External wall constructions, glazing system types, shading devices, roof construction, and HVAC systems and load centers. Wall constructions and glazing system options were mentioned in section 4.1.1, and Table (4.1). Shading devices scenarios were mentioned in section 4.1.2. Roof constructions options were the green roof that mentioned in section 4.1.4 and asphalt roof finishing. HVAC systems were discussed in chapter (5). They were natural, mechanical, and mixed-mode ventilation. Load centers was mentioned in section 6.1. The only constraint was the discomfort hours which they do not exceed 200hr. Table (6.2) displays these objectives briefly. Table (6.2): Multi-objectives of optimization process

Wall and glazing constructions WALLS GLAZING CASE01-15HB-5AG-12HB Case01-Dbl Clr 6mm/6mm Air CASE02-20SB-4.8AG-10HB Case02Dbl LoE (e3=.1) Clr 3mm/6mm Air CASE03-20HB-5AG-10HB Case03-Dbl Clr 3mm/13mm Air CASE04-10HB-1.5INSU-7HB Case04-Dbl Clr 6mm/16mm Air CASE05-20HB-3AG-20HB Case06-Sgl LoE (e2=.4) Clr 3mm CASE06-15HB-2.6INSU-10HB PVCase06-Sgl LoE (e2=.4) Clr 3mm CASE06-15HB-2.6INSU-10HB -BIPV Case10-Dbl LoE (e2=.4) Clr 6mm/16mm Air CASE07-7NS-20PC-2.8INSU-10HB Case11-Trp Clr 3mm/6mm Air CASE08-7NS-20PC-3INSU Sgl Clr 6mm CASE09-20SB-3INSU Roof- green roof GR, asphalt

185

CASE10-7NS-15PC-5AG-10HB Load center- BIPV, BIPV-PV, BIPV-PVA, BIPV-PVP, and

BIPV-PVGR CASE11-7NS-15PC-5.6AG-10HB CASE12-15HB-6.7INSU-10HB Shading devices 30 OH-50 OH-30 OH+SF, 50 OH+SF, 30 LO+OH+SF, 50 LO+OH+SF,

Pareto front point displayed four optimal solutions to minimize the energy consumption in the building which are: 1- Case 07 of external wall construction, case 03- Dbl Clr 3mm/13mm air of glazing type (overall U-value = 1.4W/m2.k), SHDs of 30 cm OH+SF (SC was between 0.7-0.6), green roof, HVAC system was mixed-mode ventilation, the loads center was BIPV-PV. Net site energy consumption was 538.96 MWh and the cost was 6067424.57 GBP. 2- Case 07 of external wall construction, case 01-Dbl Clr 6mm/6mm air of glazing type (overall U-value = 1.38W/m2.k), shading device of 30cm OH+SF0.8H (SC between 0.7-0.5), asphalt roof, HVAC system was mixed-mode ventilation, the loads center was BIPV-PV. Net site energy consumption was 790.391 MWh and the cost was 6067424.57 GBP. 3- Case 11 of external wall construction, case 04- Dbl Clr 6mm/16mm air of glazing type (overall U-value = 2 W/m2.k), shading device of 30cm OHs (SC between 0.75-0.7), green roof, HVAC system was mixed-mode ventilation, the loads center was BIPV-PV. Net site energy consumption was 971.74 MWh and the cost was 6067424.57 GBP. 4- Case 07 of external wall construction, Case06-Sgl LoE (e2=.4) Clr 3mm (overall U-value = 1.8 W/m2.k) integrated PV of glazing type, shading device of 30cm LOs, asphalt roof construction, HVAC system was natural ventilation with cooling assistance, the loads center was BIPV-PV. Net site energy consumption was 987.02 MWh and the cost was 6014379.37 GBP.

Discussion: As shown in Figure (6.5), the optimum solution that fulfilled less net site energy was the case of point 1 which was 538.96 MWh. The cost was 6067424.57 GBP.

186

Overall U value of 1.4 W/m2.k although that point 4 achieved 1.8 W/m2.k which is considered as a restricted value by PEC. SC was ranged between 0.7-0.6. 6067424.57 /32 = 189.607 GBP per apartment. Each apartment will pay 189607 /12 = 15800 GBP in a month. If pay pack were 11 years, the cost will be 1436 GBP (2053 USD) in a month. Evola and Margani (2014) recommended low U-value for Mediterranean climate countries buildings envelope components. They found that the cost will be around 59,600 €/year during 11 years Pay pack . So, it is recommended for QEAB to be NZEB that have low thermal transmittance, low shading coefficient and mixed mode ventilation. Furthermore, in most cases the occupants of multi-storey residences are not among the wealthier members of society and they find it difficult to raise capital for longer-term investments. (Waide, Guertler, & Smith, 2006) provided many public private partnership approaches that could hold much promises for refurbishment objectives, for instance, constructing an attic storey of many apartments.

Figure (6.5): A summary of NZER process for QEAB

187

6.3 Challenges and barriers

In case of Gaza, NZE process is a challengeable issue. In presence of siege and instability political situations, daily economic fluctuations represent the main barrier to implement such methods for deep energy process. Although, the sequential governments have shown a very positive attitude towards energy efficiency programs, most efforts concentrate on using PV panels in limited fields such as schools. On the other hand, retrofit and pay pack period payments are not encouraging for people to keep going in obtaining energy-efficient buildings. Also, many consumers or investors tend to lack interest in these retrofit projects either because of the decreased awareness regarding the prospect of energy savings, or lack of confidence in energy efficiency suppliers. So, NZER needs for supporting hands in the retrofit market such competent party as The Energy Management Service company (EMS) in UAE that plays a big role in the retrofit market which provides a broad range of energy efficiency solutions (Alkhateeb et al., 2016). Energy Service Companies ESCOs interest in providing innovative funding methods for retrofit processes. So, the study recommends decision makers to find energy service companies in Gaza which can support and fund such projects of energy retrofit. Also, the study recommends the other researchers to conduct other studies on NZER in Gaza context taken into consideration minimizing the cost of retrofit projects to be available for the public people.

188

Chapter 7 Conclusion and recommendations

189

Chapter 7 Conclusion and recommendations

Introduction

Net zero energy is a systematic approach that depends on the exchange benefit with the grid or any surrounding facilities or buildings. Gaza can make use of such approach to overcome the electricity shortage obstacles, on the other hands, it reduces the energy consumption in the buildings. Not only in the new buildings, but also in the existing ones in order to achieve the soul of NZE by upgrading the envelopes. Many energy measures can be applied to get NZEBs. This study used thermal transmittance, shading devices and shading coefficient, airtightness and the green roof. Also, improving the indoor air quality can be achieved by using an appropriate method of ventilation. For that, the study used shading devices, double skin facade, and the combination of double skin facade and vertical greenery systems. The notion was performed by RES generation and cost-effectiveness stages. So, this chapter displays the conclusion of the aforementioned study procedure. Then, it displays the recommendations that are the guidelines for decision makers, architects, and owners as strategies of NZER in Gaza.

7.1 Conclusion

Gaza has a plenty number of existing buildings that are considered multi-storey buildings. Multi-storey buildings enable people to have shelters for their families. Electricity shortage make them using alternative means to obtain comfort ambient in their spaces. Although its pay back, net zero energy possibilities could enable people to overcome the problem of electricity cut. Net zero energy retrofit is a way to convert our buildings to energy efficiency buildings. Also, it is a significant step toward achieving sustainability. When our consideration was NZER, this mean that the process of retrofit will be taken place within the envelope of the building, then generating energy by RES. NZER procedure consists of five main steps: 1) defining reference case (RC) parameters, 2) determining energy measures that could get energy

190

savings taking into consideration their availability in certain place locally, 3) energy measures evaluation that make use of weather data, 4) generating energy by RES, 5) The last step is cost-effectiveness step, It is an optimization step that can trade-off between these measures to get low net site energy. RES generation can be footprint or on site or a combination of them if its boundary system building site. It also can be off-site when the generation is far away of the building site or when the supplier is green grid. To accomplish the meaning of NZER for envelope, the research aims to know what type of energy assessment could be found to perform the process. Common ways are life-cycle cost, and net present value (NPV). Also, deterministic methods depend on dynamic simulation models i.e. genetic algorithms method (GAs), such as CASA approaches. Moreover, stochastic methods for evaluating the facade retrofits, it is multiple simulations using uncertain inputs and processes defined by proper probability distributions that develop a range of probable outcomes. In addition, financial evaluation of facade retrofits is commercially available with cost effective way with payback. Besides, human value assessment method is a method correlated with human factors. These are assessment tools that present a progress of energy rating system as well as LEED-EBOM certification, a Points Based System, awards credit points by evaluating the performance based on the Energy Star® Rating of the building. This enables decision makers to reward the owners who follow a NZE strategy to cut down the energy consumption in their building. Exchanging benefits could occur as a way for investment. Building industry has a big role to achieve NZEB such as solar façade as PV and PCM, vertical greenery systems, dynamic windows, nanotechnology, and others. They were clarified in section 2.5. For Al Quds engineers apartment building (QEAB) as a case study of NZER, an energy package was applied to QEAB that using locally available materials and methods. It consisted of five measures: U-value, shading devices and shading coefficient (SC), airtightness, green roof (GR), and ventilation. Low thermal transmittance was recommended. Also, low shading coefficient was recommended. If the strategy depended on natural ventilation, SC should be less 0.5-0.4. If the strategy depended on mechanical or mixed mode ventilation, SC should be limited 0.7-0.5. Airtightness saved energy about 11-20%. Green roof saved 8%. On the other hands, natural ventilation, mechanical ventilation and mixed mode ventilation were examined. Using SHDs, DSF, and GDSF in addition

191

to wind catcher integrated with them. The process was compatible with CFD in addition to type 2 of WC, glazing skylight, and thermal mass. Although, shading devices scenario used less heating and cooling loads, GDSF was recommended due its ability to improve the indoor air quality. In context of RES generation, RES generation took place in footprint and on site. BIPV-PVp scenario saved 80% of the electricity demand of the building. It produces 400.52MWh. Also, QEAB can produce 297.44 MWh annually (24.79 MWh in a month) as a surplus energy. This should be credited. QEAB can invest in the grid with 12393.5 NIC (2478.71 JD) in a month. The optimum solution was low U-value of 1.4 W/m2.k, low shading coefficient, with mixed mode ventilation. Less net site energy occurred which was 538.96 MWh. The cost was 6067424.57 GBP. If pay pack were 11 years, the cost will be 1436 GBP in a month. The whole process of NZER and results can be summarized as follows: 1) An effect energy envelope of multi-storey buildings could achieved by: - Low overall thermal transmittance value for the envelope components especially in the elevations faced west and south directions. - Using smart materials and shading management that response to the ambient circumstances. - The shape of SHDs is able to reduce the energy consumption as well as egg crate lovers. - Using Low shading coefficient for fenestration systems in order to get energy savings. It can be achieved by an efficient glazing which have low SHGC to prevent incident solar radiation to get into the space. - The airtightness fabric could reduce the energy consumption including thermal break for the frames of the windows. - The more the height of plants for green roof, the effect on heating and cooling loads would be more effective. 2) Energy savings could be obtain by an efficient strategy of ventilation using shading, buoyancy-driven ventilation and solar chimney by controlling the components of the envelope. - For natural and mixed mode ventilation, not only SHDs could block the sun to enter to the space, but also they are able to be as wind catcher by using horizontal elements and avoiding the vertical ones.

192

- Ventilated double skin windows achieve low SHGC without shading devices improve the indoor air quality by create external airflow within the outer layer of the windows. - Installing shading devices in between its pans can save energy. It is profitable for NZEBs to have controller system to manage the amount of sun entered to the space. Therefore, extra loads would be avoided whether in summer nights or in winter days in order to achieve high level of thermal comfort for occupants. - As for DSF, two issues should be controlled: the width of DSF itself and the temperature of the skin façade. Slim type double skin window can be used in buoyancy-driven natural ventilation in residential multi storey compounds. Also, installing shading devices within the cavity helps to reduce the temperature of the air inside the cavity that it will improve the air replacement inside the space, therefore the thermal comfort for occupants. - Using plantation combined with WC proved its capability to improve the indoor air quality. - Using CFD tool is beneficial to study the buoyancy-driven for natural ventilation. 1) Wind catcher coupled with earth tunnel, or cooling pad installed inside the ventilation shafts can increase the air replacement rate inside the space. 2) Using glazing skylight should be coupled with ground microclimate by plantation and opening the slab in the ground slab level. 3) Using SHDs is beneficial if it coupled with DSF. 4) GDSF coupled with WC can decrease the internal air velocity which it required for thermal comfort. 4) Thermal mass charge and discharge process can reduce the AT even if the floor was the upper. 3) For RES generation, using PV panels whether on footprint and on sit generation. - An effective scenario of generation depends on using PV panels integrated with envelope components such as BIPV and shading devices incorporated with PV.

193

7.2 Recommendations

The recommendations are as a strategies for implementing NZE into retrofit projects of buildings. These strategies related to four main sectors that related to NZER. They are decision makers, architects, and owners & stakeholders.

7.2.1 Recommendations for decision makers: 1. Palestine Energy and natural resources Authority PENRA should put standards for developing and regulating the process of NZE. 2. PENRA should be connected with Palestine standard Institution PSI in order to adjust the quality of process of NZE especially if it was related to retrofit. 3. PENRA cooperated with PSI should be responsible about the quality of metrics that weighted what the energy will produce within the building to what it will be surplus going to utility. 4. Promote the concept of NZEB and NZER by holding an awareness campaign to encourage owners to convert their buildings to plants of electricity especially if they are multi-storey buildings. 5. Find rewards and incentives to motivate owners to adopt NZE in their building as well as loans, or economic prevailing. These rewards depending on a Rating system as LEED-EBOM certification. 6. Using optimization tools to estimate the appropriate incentives for NZER process such as BEopt provided by LBNL. 7. Polarization experts of NZER to make use of their experience of retrofit projects. 8. Reinforce cooperation with private sector to promote the idea of NZER. 9. Provide technical support for individual retrofit projects. 10. Encourage the local industry to produce qualified materials for NZE such as PCM, products of BIPV, nanotechnology as aerogel. Therefore, they would be rewarded to keep up with the new technologies. 11. Find green infrastructure that buildings could be connected with in order to complete the image of energy savings in Whole Gaza. 12. Find energy service companies in Gaza which can support and fund such projects of energy retrofit.

7.2.2 Recommendations for architects and designers Especially if NZER is applied to multi-storey buildings. 13. Use energy simulation tools as DesignBuilder to assess and evaluate the energy measures of NZE retrofit process

194

14. Provide an efficient solution for their measures such as appropriate U-value and shading coefficient SC, they could get satisfied energy saving. 15. Use sun tracking systems fundamentally in the study of SHDs especially when they are horizontally expanded in order to achieve the desired thermal comfort. 16. In order to get a satisfied level of thermal comfort in the retrofit projects, it is recommended to include the airtightness strategy into the ventilation study. 17. Use the green roof with different layers which consist of drainage and barriers for roots plus channels for water in order to reduce the heat conduction that flows to a floor below the roof. 18. Invent types of glazing systems that help in the subject of ventilation as well as double skin windows. 19. Use the wind driven strategy that coupled with double skin facade or vertical greenery systems especially in case of natural ventilation. 20. Benefit from GDSF features that reduce the energy consumption, also, use deciduous vines climber that it could occupants to make use of the sun in winter. 21. In future buildings, open the slabs of the ground levels of the ventilation shafts in order to induce the air to move inside them especially in the south direction coupled with using plants. 22. Use passive strategies as well as thermal mass especially in the upper floors in order to mitigate the inside air temperature, therefore, achieve thermal comfort conditions. 23. Use the ventilation shafts of the multi-storey buildings for ventilation as wind catcher. 24. Obtain low SC for fenestration systems that should be not exceeded 0.5 in case of natural ventilation, and 0.7 in case of mechanical ventilation. 25. The adaption of traditional elements such as Mashrabiyya and Malqaf could benefit our strategy of natural HVAC, especially in the southern zones. 26. For mechanical HVAC, use a combination of double skin façade and vertical greenery systems for more energy saving in the building. 27. Use the heat expressions in the retrofit process such as SC, SHG and GLF that can help them to identify which type of fenestration systems can save energy efficiently. 28. In case of natural ventilation, DSF should be studied carefully. The inner layer glazing should be double and emissivity, in addition, integrate shading devices in its cavity. 29. The retrofit process should be supported with optimization tools such as Pareto front point in order to tradeoff between measures in case of NZER. Then get more energy savings of net site energy. 30. Hot and dry climate: Well-insulated building envelope with limited fenestration area; glazing with very low SHGC and shading from direct sunlight in summer; reflective exterior envelope surfaces essentially; solar

195

powered AC equipment can provide day-time cooling; thermal mass and lower night-time temperatures provide comfortable indoor conditions after sunset (Mitterer et al., 2012).

7.2.3 Recommendations for owners, and stakeholder 31. Stakeholders especially housing cooperating associations should look forward to converting their buildings to NZEB. 32. Find technical teams connected with the technical one of PENRA. 33. Have the awareness that NZER is an imperative need to cut down energy consumption in their buildings, this would be via designers. 34. In spite of the cost of the process and its payback, NZE enables them to invest with the utility. 35. By NZEB, Bill of the utility electricity should be reduced too much. 36. If the owners are following the promoting of NZE, they will get incentives that should be inherently compatible with Rating system, RES certification. 37. Have a maintenance team for technical solution. 38. Obligate renters if they share the process of NZER process 39. Find permanent observation that keep an eye on the NZEB appliance such as cameras with sensors to treat any surprised action that could damage the system. 40. Use management tools for generating the energy as central computer that regulates and observes the process.

....﴿ تم بحمد هللا ﴾....

196

References

197

References Acred, Andrew, & Hunt, Gary R. (2013). Passive ventilation in multi-storey atrium buildings: A first-order design guide. Paper presented at the Proceedings of the 34th AIVC Conference, Athens. https://www.researchgate.net/publication/271850301 Aelenei, Laura, Pereira, Ricardo, Gonçalves, Helder, & Athienitis, Andreas. (2014). Thermal performance of a hybrid BIPV-PCM: Modeling, design and experimental investigation. Energy Procedia, 48, 474-483. doi: 10.1016/j.egypro.2014.02.056 Aksamija, Ajla. (2015). Regenerative design of existing buildings for net-zero energy use. Procedia Engineering, 118, 72-80. doi: 10.1016/j.proeng.2015.08.405 Aksamija, Ajla. (2017). Energy performance of different types of double skin facades in various climates. Architecture of Complexity, 500-509. Al-Auqeily, Wael A., & Al-Yousif, Ibrahim j. (2008). Reduction cooling load using intelligent envelope system. The Iraqi Journal of Archutecture, 48(14-15), 76-96. Al-Tamimi, Nedhal A, & Fadzil, Sharifah Fairuz Syed. (2011). The potential of shading devices for temperature reduction in high-rise residential buildings in the tropics. Procedia Engineering, 21, 273-282. doi: 10.1016/j.proeng.2011.11.2015 Alaidroos, Alaa, & Krarti, Moncef. (2015). Optimal design of residential building envelope systems in the Kingdom of Saudi Arabia. Energy and Buildings, 86, 104-117. doi: http://dx.doi.org/10.1016/j.enbuild.2014.09.083 Alawadhi, Esam M., & Alqallaf, Hashem J. (2011). Building roof with conical holes containing PCM to reduce the cooling load: Numerical study. Energy Conversion and Management, 52(8–9), 2958-2964. doi: 10.1016/j.enconman.2011.04.004 Albadry, Somaya. (2016). Feasibility of converting existing residential buildings to net zero- energy buildings in egypt a case study. (Master of science in sustainable development), The Amercan University in Cairo. Retrieved from http://dar.aucegypt.edu/bitstream/handle/10526/4771/Somaya%20Albadry%20Final %20thesis%20-%20after%20defense%20(2).pdf?sequence=1 Alberto, André, Ramos, Nuno M. M., & Almeida, Ricardo M. S. F. (2017). Parametric study of double-skin facades performance in mild climate countries. Journal of Building Engineering, 12, 87-98. doi: https://doi.org/10.1016/j.jobe.2017.05.013 Alkhateeb, E., Hijleh, B. Abu, Rengasamy, E., & Muhammed, S. (2016). Building refurbishment stratigies and their impact on saving energy in the united arab emirates. Paper presented at the SBE16 Dubai, Dubai-UAE. http://content.buid.ac.ae/events/Proceedings/SBE16D154.pdf Altan, H, & Tabriz, MB. (n.d.). Using wind catchers as a passive cooling system for residential buildings in Cyprus. Annie Hunter Block, Stephen J. Livesley, & Williams, Nicholas S.G. (2012). Responding to the urban heat island: A review of the potential of green infrastructure. Retrieved from http://www.vcccar.org.au/sites/default/files/publications/VCCCAR%20Urban%20H eat%20Island%20-WEB.pdf. Arcuri, Natale, Carpino, Cristina, & De Simone, Marilena. (2016). The role of the thermal mass in nZEB with different energy systems. Energy Procedia, 101, 121-128. doi: 10.1016/j.egypro.2016.11.016 Arumägi, Endrik, Mändel, Maris, & Kalamees, Targo. (2015). Method for assessment of energy retrofit measures in milieu valuable buildings. Energy Procedia, 78, 1027- 1032. doi: 10.1016/j.egypro.2015.11.052 Ascione, Fabrizio, Bianco, Nicola, De Masi, Rosa Francesca, Dousi, Maria, Hionidis, S., Kaliakos, S., . . . Vassilakopoulou, Kostantina. (2017). Design and performance

198

analysis of a zero-energy settlement in Greece. International Journal of Low-Carbon Technologies, 12(2), 141-161. doi: 10.1093/ijlct/ctw003 Ascione, Fabrizio, De Masi, Rosa Francesca, de Rossi, Filippo, Ruggiero, Silvia, & Vanoli, Giuseppe Peter. (2016). Optimization of building envelope design for nZEBs in Mediterranean climate: Performance analysis of residential case study. Applied Energy, 183, 938-957. doi: 10.1016/j.apenergy.2016.09.027 Asdrubali, Francesco, D’Alessandro, Francesco, Baldinelli, Giorgio, & Bianchi, Francesco. (2014). Evaluating in situ thermal transmittance of green buildings masonries—A case study. Case Studies in Construction Materials, 1(Supplement C), 53-59. doi: 10.1016/j.cscm.2014.04.004 Asfour, Omer. (2014). Thermal analysis using Ecotect – part A. Ashjaee, Shiva Sabeti, Faizi, Mohsen, Seraj, Fateme Mehdizade, & Zarouri, Amir Saam Zarif. (2015). Assessing the effect of window, its shape and shading devices on the heating and cooling energy consumption (in the region of Mashhad city). Paper presented at the 9th symposium on advances in Science & Technology (9thSASTech 2014), , Mashad, Iran. https://www.ctts.in/assets/upload/4103Shiva%20Sabeti%20Ashjaee- PAPAER.pdf ASHRAE Vision 2020 Ad Hoc Committee. (2008). Producing net zero energy buildings. Retrieved from file:///D:/thesis%206-9- 2016/assess/20080226_ashraevision2020%20(1).pdf. Athienitis, Andreas K., Bambara, James, O’Neill, Brendan, & Faille, Jonathan. (2011). A prototype photovoltaic/thermal system integrated with transpired collector. Solar energy, 85(1), 139-153. doi: 10.1016/j.solener.2010.10.008 Attia, Shadi. (2012). A tool for design decision making-zero energy residential buildings in hot humid climates. (PhD thesis), Université catholique de Louvain. Retrieved from https://books.google.ps/books?id=3qzRIfvS6NMC&printsec=frontcover Attia, Shady. (2011). State of the art of existing early design simulation tools for net zero energy buildings: a comparison of ten tools. Architecture et climat Retrieved from https://orbi.uliege.be/handle/2268/168349. Attia, Shady, Gratia, Elisabeth, De Herde, André, & Hensen, Jan L. M. (2012). Simulation- based decision support tool for early stages of zero-energy building design. Energy and Buildings, 49, 2-15. doi: 10.1016/j.enbuild.2012.01.028 Atzeri, A, Pernigotto, Giovanni, Cappelletti, Francesca, Gasparella, Andrea, & Tzempelikos, Athanasios. (2013). Energy performance of shading devices for thermal and lighting comfort in offices. Proceedings of the BSA. Ayyad, Karim M., & Fekry, Ahmed A. (2016). Green retrofitability index (GRI) as an indicator for decision-makers in green retrofitting projects. Procedia Environmental Sciences, 34, 233-244. doi: 10.1016/j.proenv.2016.04.022 Azarbayjani, Mona. (2010). Beyond arrows: Energy performance of a new, naturally ventilated, double-skin facade configuration for a high-rise office building in Chicago. (Doctoral dissertation), University of Illinois at Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/17026 Aziiz, Akhlish Diinal, & Koerniawan, Mochamad Donny. (2017). Buoyancy-driven ventilation generated by the double-skin façade of a high-rise building in tropical climate: Case study bandung, indonesia. Paper presented at the MATEC Web of Conferences. https://www.matec- conferences.org/articles/matecconf/pdf/2017/52/matecconf_eacef2017_01016.pdf Baba, Mutasim, Dieck, Elias, & Stephan, Anton. (2011). An ultra energy efficient building in Palestine. Paper presented at the Proceedings of the 4th international energy conference–Palestine. https://staff.najah.edu/sites/default/files/An_Ultra_Energy_Efficient_Building_in_Pa lestine.pdf

199

Baetens, Ruben, Jelle, Bjørn Petter, & Gustavsen, Arild. (2011). Aerogel insulation for building applications: A state-of-the-art review. Energy and Buildings, 43(4), 761- 769. doi: 10.1016/j.enbuild.2010.12.012 Ballarini, Ilaria, Pichierri, Sesil, & Corrado, Vincenzo. (2015). Tracking the energy refurbishment processes in residential building stocks. The pilot case of Piedmont region. Energy Procedia, 78, 1051-1056. doi: 10.1016/j.egypro.2015.11.069 Baran, Irina, Dumitrescu, Laura, & Pescaru, Radu Aurel. (2016). Thermal rehabilitation technology and the nearly zero-energy buildings. Romanian representative education buildings-case study. Procedia Technology, 22, 358-364. doi: 10.1016/j.protcy.2016.01.024 Barbosa, Sabrina, & Ip, Kenneth. (2014). Perspectives of double skin façades for naturally ventilated buildings: A review. Renewable and Sustainable Energy Reviews, 40, 1019- 1029. doi: 10.1016/j.rser.2014.07.192 Barbosa, Sabrina, Ip, Kenneth, & Southall, Ryan. (2015). Thermal comfort in naturally ventilated buildings with double skin façade under tropical climate conditions: The influence of key design parameters. Energy and Buildings, 109, 397-406. doi: 10.1016/j.enbuild.2015.10.029 Barthelmes, Verena, Becchio, Cristina, Bottero, Marta, & Corgnati, Stefano. (2014). The influence of energy targets and economic concerns in design strategies for a residential nearly-zero energy building. Buildings, 4(4), 937. doi: 10.3390/buildings4040937 Basarir, Bahar, Diri, Berrin Sahin, & Diri, Cüneyt. (2012). Energy efficient retrofit methods at the building envelopes of the school buildings. Mimar Sinan Fine Arts University, Istanbul, Findikli, 34427. BBSA. (2016). Solar shading saves energy. The British Blind and Shutter Association Retrieved from file:///D:/master%20thesis%20work/Master%20thesis/an%20analysis%20part/pdf/S olar-shading-saves-energy.pdf. Becchio, C., Ferrando, D. G., Fregonara, E., Milani, N., Quercia, C., & Serra, V. (2015). The cost optimal methodology for evaluating the energy retrofit of an ex-industrial building in Turin. Energy Procedia, 78, 1039-1044. doi: 10.1016/j.egypro.2015.11.057 Berardi, Umberto. (2015). Development of glazing systems with silica aerogel. Energy Procedia, 78, 394-399. doi: 10.1016/j.egypro.2015.11.682 Berardi, Umberto. (2016). The outdoor microclimate benefits and energy saving resulting from green roofs retrofits. Energy and Buildings, 121(Supplement C), 217-229. doi: 10.1016/j.enbuild.2016.03.021 Bernheim, Anthony, Hodgson, Alred, & Persily, Andrew K. (2015). High performance IAQ specification for net zero energy homes. Paper presented at the Proceedings of Healthy Buildings 2015, Boulder, CO. http://ws680.nist.gov/publication/get_pdf.cfm?pub_id=917949 Bizzarri, Giacomo, Gillott, Mark, & Belpoliti, Vittorino. (2011). The potential of semitransparent photovoltaic devices for architectural integration: The development of device performance and improvement of the indoor environmental quality and comfort through case-study application. Sustainable Cities and Society, 1(3), 178-185. doi: 10.1016/j.scs.2011.07.003 Bobrowicz, Lila. (n.d). Features of zero-net energy buildings. http://www.academia.edu/download/37651091/Features_of_Zero- Net_Energy_Buildings_-_Lila_Bobrowicz.pdf Boranian, Aaron Patrick, Zakirova, Betka, Sarvaiya, Jatin Narotam, Jadhav, Nilesh Y., Pawar, Priya, & Zhe, Zhang. (2013). Building energy efficiency r&d roadmap. The National Climate Change Secretariat of Singapore Retrieved from https://www.nccs.gov.sg/sites/nccs/files/Roadmap_BEE_20140729.pdf.

200

Brinker, C. Jeffrey, & Ginger, David. (2011). Nanotechnology for sustainability: Energy conversion, storage, and conservation Nanotechnology research directions for societal needs in 2020: Retrospective and outlook (pp. 261-303). Dordrecht: Springer Netherlands doi: 10.1007/978-94-007-1168-6_7 Brittle, John P. (2017). Passive system integration for office buildings in hot climates. (Doctoral thesis), Loughborough University. Retrieved from https://dspace.lboro.ac.uk/dspace-jspui/bitstream/2134/23912/2/Thesis-2017- Brittle.pdf Building & Construction Authority-Singabor. (2004). Guidelines on envelope thermal transfer value for buildings. Retrieved from https://www.bca.gov.sg/PerformanceBased/others/ETTV.pdf. Buonomano, Annamaria, De Luca, Giuseppina, Montanaro, Umberto, & Palombo, Adolfo. (2016). Innovative technologies for NZEBs: An energy and economic analysis tool and a case study of a non-residential building for the Mediterranean climate. Energy and Buildings, 121, 318-343. doi: 10.1016/j.enbuild.2015.08.037 Calautit, John Kaiser, & Hughes, Ben Richard. (2014). Measurement and prediction of the indoor airflow in a room ventilated with a commercial wind tower. Energy and Buildings, 84, 367-377. doi: 10.1016/j.enbuild.2014.08.015 Cao, Xiaodong, Dai, Xilei, & Liu, Junjie. (2016). Building energy-consumption status worldwide and the state-of-the-art technologies for zero-energy buildings during the past decade. Energy and Buildings, 128, 198-213. doi: 10.1016/j.enbuild.2016.06.089 Capener, Carl-Magnus, & Sikander, Eva. (2015). Green building envelopes – moisture safety in ventilated light-weight building envelopes. Energy Procedia, 78, 3458-3464. doi: 10.1016/j.egypro.2015.11.179 Carmichael, Cara, & Managan, Katrina. (2013). Reinventing existing buildings: Eight steps to net zero energy. The Institute for Building Efficiency: an initiative of Johnson Controls Retrieved from http://www.buildingefficiencyinitiative.org/sites/default/files/legacy/InstituteBE/me dia/Library/Resources/Green-Buildings/Reinventing-Existing-Buildings-8-Steps-to- Net-Zero-Energy_JCI-RMI.pdf. Casini, Marco. (2014). Smart materials and nanotechnology for energy retrofit of historic buildings. International Journal of Civil and Structural Engineering– IJCSE, 1(3), 88- 97. Causone, Francesco, Carlucci, Salvatore, Pagliano, Lorenzo, & Pietrobon, Marco. (2014). A zero energy concept building for the Mediterranean climate. Energy Procedia, 62, 280-288. doi: 10.1016/j.egypro.2014.12.389 Cellai, G, Carletti, C, Sciurpi, F, & Secchi, S. (2014). Transparent building envelope: windows and shading devices typologies for energy efficiency refurbishments. In Magrini, A. (Ed.), Building refurbishment for energy performance (pp. 61-118): Springer doi: 10.1007/978-3-319-03074-6_2, Chen, Deliang, & Chen, Hans Weiteng. (2013). Using the Köppen classification to quantify climate variation and change: An example for 1901–2010. Environmental Development, 6, 69-79. doi: 10.1016/j.envdev.2013.03.007 Cheong, Chang Heon, Kim, Taeyeon, & Leigh, Seung-Bok. (2014). Thermal and daylighting performance of energy-efficient windows in highly glazed residential buildings: Case study in Korea. Sustainability, 6(10), 7311-7333. doi: 10.3390/su6107311 Cho, Kyung-joo, & Cho, Dong-woo. (2018). Solar heat gain coefficient analysis of a slim-type double skin window system: Using an experimental and a simulation method. Energies, 11(1), 115. doi: 10.3390/en11010115 Chua, Kian Jon, & Chou, Siaw Kiang. (2010). Evaluating the performance of shading devices and glazing types to promote energy efficiency of residential buildings. Building Simulation, 3(3), 181-194. doi: 10.1007/s12273-010-0007-2

201

CMHC. (2012). Canada mortgage and housing corporation: Highly energy efficient building envelope retrofits for houses. Retrieved from https://www.cmhc- schl.gc.ca/odpub/pdf/67629.pdf?lang=en. Dardir, Mohamed. (2012). Natural ventilation techniques as a base for environmental passive architecture. (Master of science degree in architecture engineering), Ain Shams University. Retrieved from http://www.cpas- egypt.com/pdf/MohamedDarder/Ms.c/Mohamed%20A.%20Dardir%20MSc%20The sis%20MOD..pdf De Angelis, Enrico, Pansa, Giorgio, & Serra, Ermanno. (2014). Research of economic sustainability of different energy refurbishment strategies for an apartment block building. Energy Procedia, 48, 1449-1458. doi: 10.1016/j.egypro.2014.02.164 Deng, S., Wang, R. Z., & Dai, Y. J. (2014). How to evaluate performance of net zero energy building – A literature research. Energy, 71, 1-16. doi: 10.1016/j.energy.2014.05.007 DesignBuilder 2, 1. (2009). User's Manual. DesignBuilder V5. DesignBuilder v5 guideline. Retrieved 10-9-2017, from https://www.designbuilder.co.uk/helpv5.0/ EC- Joint Research Centre. (2013). High performance buildings, design and evaluation methodologies. Paper presented at the the EU Sustainable Energy Week, Brussels. http://iet.jrc.ec.europa.eu/energyefficiency/sites/energyefficiency/files/final_handout s_printer.pdf El-Darwish, Ingy, & Gomaa, Mohamed. (2017). Retrofitting strategy for building envelopes to achieve energy efficiency. Alexandria Engineering Journal, 56(4), 579-589. doi: 10.1016/J.aej.2017.05.011 Elgendy, Rana, & Mekkawi, Gehad. (2015). Simulation-based studies to reach the net zero energy target for a housing prototype in Alexandria, Egypt. Paper presented at the The 15th International Conference on Civil and Architectural Engineering (ICCAE), Amsterdam, Netherlands. https://www.researchgate.net/publication/320404051 Evangelisti, Luca, Guattari, Claudia, & Gori, Paola. (2015). Energy retrofit strategies for residential building envelopes: An Italian case study of an early-50s building. Sustainability, 7(8), 10445. doi: 10.3390/su70810445 Evins, Ralph, Pointer, Philip, & Vaidyanathan, Ravi. (2011). Multi-objective optimisation of the configuration and control of a double-skin facade. Sustainability, 7, 10445-10460. doi: 10.1016/j.foar.2012.06.002 Evola, Gianpiero, & Margani, Giuseppe. (2014). Energy retrofit towards net zeb. Paper presented at the Architectural Research through to Practice: 48th International Conference of the Architectural Science Association 2014. https://www.researchgate.net/publication/276865886 EWC. (2013). Design guidance for new windows in a hot climate. Efficient Windows Collaborative Retrieved from http://www.efficientwindows.org/downloads/HotDesignGuide_new.pdf. Fan, Yuling, & Xia, Xiaohua. (2015). A multi-objective optimization model for building envelope retrofit planning. Energy Procedia, 75, 1299-1304. doi: 10.1016/j.egypro.2015.07.193 Farrar-Nagy, Sara, Anderson, Ren, Hancock, CE, & Reeves, Paul. (2000). Impacts of shading and glazing combinations on residential energy use in a hot dry climate. Paper presented at the the 2000 ACEEE Summer Study on Energy Efficiency in Buildings, Pacific Grove, California. https://www.nrel.gov/docs/fy00osti/28203.pdf Farrokhzad, Mohammad. (2014). Double skin glass façade and its effect on saving energy. Iran University of Science & Technology, 24(2), 65-74. Feustel, Helmut E, & Diamond, Richard C. (1998). Air flow distribution in a high-rise residential building. Paper presented at the Proceedings of roomvent conference. https://buildings.lbl.gov/sites/default/files/lbnl-43642.pdf

202

Fiorentini, Massimo, Cooper, Paul, & Ma, Zhenjun. (2015). Development and optimization of an innovative HVAC system with integrated PVT and PCM thermal storage for a net- zero energy retrofitted house. Energy and Buildings, 94, 21-32. doi: 10.1016/j.enbuild.2015.02.018 Firląg, Szymon, Yazdanian, Mehrangiz, Curcija, Charlie, Kohler, Christian, Vidanovic, Simon, Hart, Robert, & Czarnecki, Stephen. (2015). Control algorithms for dynamic windows for residential buildings. Energy and Buildings, 109, 157-173. doi: 10.1016/j.enbuild.2015.09.069 Frontini, F, Scognamiglio, A, Graditi, G, Lopez, P, Pellegrino, M, & ENEA, UTTP FOTO. (2013). From BIPV to building component. Paper presented at the 28th European Photovoltaic Solar Energy Conference and Exhibition, Portici, Italy. Gaillard, Leon, Giroux-Julien, Stéphanie, Ménézo, Christophe, & Pabiou, Hervé. (2014). Experimental evaluation of a naturally ventilated PV double-skin building envelope in real operating conditions. Solar energy, 103, 223-241. doi: 10.1016/j.solener.2014.02.018 Gao, Tao, Jelle, Bjørn Petter, & Gustavsen, Arild. (2016). Building integration of aerogel glazings. Procedia Engineering, 145, 723-728. doi: 10.1016/j.proeng.2016.04.090 GhaffarianHoseini, AmirHosein, Berardi, Umberto, GhaffarianHoseini, Ali, & Makaremi, Nastaran. (2012). Intelligent facades in low-energy buildings. British Journal of Environment & Climate Change, 2(4), 437-464. Ghoneim, Adel A. (2015). Achieving net zero energy building in a hot climate using integrated photovoltaic and parabolic trough collectors. International Scholarly and Scientific Research & Innovation, 9(7), 703-709. doi: 10.1999/1307-6892/10002413 Gilani, Sara, Montazeri, Hamid, & Blocken, Bert. (2016). CFD simulation of stratified indoor environment in displacement ventilation: Validation and sensitivity analysis. Building and Environment, 95, 299-313. doi: 10.1016/j.buildenv.2015.09.010 Giovannetti, Federico, Kirchner, Maik, Sass, Rodja, & Rockendorf, Gunter. (2016). Enameled glass panels for solar thermal building envelopes. Energy Procedia, 91, 49-55. doi: 10.1016/j.egypro.2016.06.170 Grigoropoulos, Evangelos. (2015). Effective ventilation strategies for net zero energy buildings in hot climates. (Master of science in energy systems), International Hellenic. Retrieved from https://repository.ihu.edu.gr/xmlui/bitstream/handle/11544/137/IHU_Energy_Thesis _Grigoropoulos_Evangelos_final.pdf?sequence=1 Grigoropoulos, Evangelos, Anastaselos, Dimitrios, Nižetić, Sandro, & Papadopoulos, Agis M. (2017). Effective ventilation strategies for net zero-energy buildings in Mediterranean climates. International Journal of Ventilation, 16(4), 291-307. doi: 10.1080/14733315.2016.1203607 Hamid, Khairuddin Ab., Ono, Osamu, Bostamam, Anas Muhamad, & Ling, Amy Poh Ai (Eds.). (2015). The Malaysia-Japan Model on Technology Partnership: Springer. https://link.springer.com/book/10.1007/978-4-431-54439-5#toc Handbook-Fundamentals, ASHRAE. (2001). Residential cooling and heating load calculations: ASHRAE handbook-fundamentals. https://sovathrothsama.files.wordpress.com/2016/03/ashrae-hvac-2001- fundamentals-handbook.pdf Haredy, Abdullah. (2016). Simulation of photovoltaic airflow windows for indoor thermal and visual comfort and electricity generation. (Dectoral thesis), University of Nottingham. Retrieved from http://eprints.nottingham.ac.uk/id/eprint/32523 He, Qiong, & Ng, S Thomas. (2017). Applicability of overhangs for energy saving in existing high-rise housing in different climates. World Academy of Science, Engineering and Technology, International Journal of Civil, Environmental, Structural, Construction and Architectural Engineering, 11(2), 132-138. doi: 10.1999/1307-6892/10006401

203

Hermelink, Andreas, Schimschar, S, Boermans, T, Pagliano, L, Zangheri, P, Armani, R, . . . Musall, E. (2013). Towards nearly zero-energy buildings. Definition of common principles under the EPBD. Final Report. Ecofys by order of the European Commission. from http://www.leonardo-energy.info/sites/leonardo- energy/files/documents-and-links/20140123_ecofys_webinar_towards_nzeb_f.pdf Hien, Wong Nyuk, & Istiadji, Agustinus Djoko. (2003). Effects of external shading devices on daylighting and natural ventilation. Paper presented at the Proceedings of the 8th International IBPSA Conference, Eindhoven, The Netherlands. http://www.ibpsa.org/proceedings/bs2003/bs03_0475_482.pdf Hong, Taehoon, Kim, Jimin, Lee, Juyoung, Koo, Choongwan, & Park, Hyo. (2013). Assessment of seasonal energy efficiency strategies of a double skin façade in a monsoon climate region. Energies, 6(9), 4352. doi: 10.3390/en6094352 Huang, Joe, Hanford, James, & Yang, Fuqiang. (1999). Residential heating and cooling loads component analysis. Lawrence berkeley national laboratory, university of california Retrieved from http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.593.3559&rep=rep1&type =pdf. Huang, Kuo-Tsang, Liu, Kevin Fong-Rey, & Liang, Han-Hsi. (2015). Design and energy performance of a buoyancy driven exterior shading device for building application in taiwan. Energies, 8(4), 2358-2380. doi: 10.3390/en8042358 Hussain, Shafqat, & Oosthuizen, Patrick H. (2012). Numerical study of buoyancy-driven natural ventilation in a simple three-storey atrium building. International Journal of Sustainable Built Environment, 1(2), 141-157. doi: 10.1016/j.ijsbe.2013.07.001 Idchabani, Rachida, El Ganaoui, Mohamed, & Sick, Friedrich. (2017). Analysis of exterior shading by overhangs and fins in hot climate. Energy Procedia, 139, 379-384. doi: 10.1016/j.egypro.2017.11.225 IEA. (2013a). Technology roadmap energy efficient building envelopes. International Energy Agency Retrieved from https://www.iea.org/publications/freepublications/publication/TechnologyRoadmap EnergyEfficientBuildingEnvelopes.pdf. IEA. (2013b). Transition to sustainable buildings, strategies and opportunities to 2050. International Energy Agency Retrieved from http://www.iea.org/publications/freepublications/publication/transition-to- sustainable-buildings.html. Ioannidis, Z, Buonomano, A, Athienitis, AK, & Stathopoulos, T. (2016). A detailed dynamic model of multi-story double skin facades with integrated photovoltaic panels. Jaafar, Badrulzaman, Said, Ismail, Reba, Mohd Nadzri Md, & Rasidi, Mohd Hisham. (2015). An experimental study on bioclimatic design of vertical greenery systems in the tropical climate The Malaysia-Japan Model on Technology Partnership (pp. 369- 376): Springer Jaafar, Badrulzaman, Said, Ismail, Reba, Mohd Nadzri Md, & Rasidi, Mohd Hisyam. (2013). Impact of vertical greenery system on internal building corridors in the tropic. Procedia-Social and Behavioral Sciences, 105, 558-568. doi: 10.1016/j.sbspro.2013.11.059 Jordan, Sabina, Hafner, Jože, Kuhn, Tilmann, Legat, Andraž, & Zbašnik-Senegačnik, Martina. (2015). Evaluation of various retrofitting concepts of building envelope for offices equipped with large radiant ceiling panels by dynamic simulations. Sustainability, 7(10), 13169. doi: 10.3390/su71013169 Kahloot, mohammad. (n.d). Impact of technological development on construction systems (high buildings). Kaluarachchi, Y, Jones, K, James, P, Jentsch, M, Baha, AS, Clements-Croome, D, & Gann, D. (2005). Building facades: sustainability, maintenance and refurbishment. Paper

204

presented at the Proceedings of the Institution of Civil Engineers-Engineering Sustainability. http://www.icevirtuallibrary.com/doi/abs/10.1680/ensu.2005.158.2.89 Kamal, Mohammad Arif. (2012). An overview of passive cooling techniques in buildings: design concepts and architectural interventions. Acta Technica Napocensis: Civil Engineering & Architecture, 55(1), 84-97. Kamel, Ehsan, & Memari, Ali M. (2016). Different methods in building envelope energy retrofit. Paper presented at the 3rd Residential Building Design & Construction Conference Penn State, University Park http://www.phrc.psu.edu/assets/docs/Publications/2016RBDCCPapers/Kamel-2016- RBDCC.pdf Kang, Gyumin, Kang, Kinam, & Song, Doosam. (2015). Optimized blind control method to minimize heating, cooling and lighting energy. Energy Procedia, 78(Supplement C), 2857-2862. doi: 10.1016/j.egypro.2015.11.651 Kapsalaki, Maria. (2013). Economic-efficient design of residential net zero energy buildings with respect to local context. (Dectoral thesis), Universidade do Porto, Portugal. Retrieved from file:///D:/master%20thesis%20work/Master%20thesis/thesis%206-9- 2016/blinds/New%20folder/000155028.pdf Karaguzel, Omer Tugrul, & Lam, Khee Poh. (2011). The consortium for building energy innovation (CBEI), development of whole-building energy performance benchmarks for retrofit projects. Retrieved from http://cbei.psu.edu/wp- content/uploads/2016/07/Development-of-Whole-Building-Energy-Performance- Benchmarks.pdf. Karzem, George. (2011). Green building is a national issue affecting the Palestinian entity. Afaq Environmental Magazine, (36). http://www.maan- ctr.org/magazine/Archive/Issue36/topic4.php Khoshbakht, Maryam, Gou, Zhonghua, Dupre, Karine, & Altan, Hasim. (2017). Thermal environments of an office building with double skin facade. Journal of Green building, 12(3), 3-22. doi: 10.3992/1943-4618.12.3.3 Kinnane, Oliver, & Prendergast, Tom. (2014). Assessment of double skin facade passive thermal buffer effect. Paper presented at the Passive Low Energy Architecture Conference, Ahmedabad, India. http://www.plea2014.in/wp- content/uploads/2014/12/Paper_8B_2749_PR.pdf Kinney, Satkartar, & Piette, Mary Ann. (2002). Development of a California commercial building benchmarking database. Paper presented at the the ACEEE 2002 Summer Study on Energy Efficiency in Buildings, Pacific Grove, California. http://www.escholarship.org/uc/item/69s7t11x Kohta Ueno, Joseph Lstiburek, & Bergey, Daniel. (2012). Multifamily ventilation retrofit strategies. Building Science Corporation Retrieved from https://buildingscience.com/documents/bareports/ba-1209-multifamily-ventilation- retrofit-strategies/view. Konstantinou, Thaleia. (2014). Facade refurbishment toolbox.: Supporting the design of residential energy upgrades: TU Delft. https://www.amazon.com/Facade- Refurbishment-Toolbox-Supporting-Residential-ebook/dp/B00NBVYCVI Konstantinou, Thaleia. (2015). A methodology to support decision-making towards an energyefficiency conscious design of residential building envelope retrofitting. Buildings, 5(4), 1221. doi: 10.3390/buildings5041221 Koo, Bokyoung, Lee, Keonho, An, Youngsub, & Lee, Kyudong. (2017). Solar heat gain reduction of ventilated double skin windows without a shading device. Sustainability, 10(1), 64. doi: 10.3390/su10010064 Kulkarni, Aditya Arun. (2011). Impact of continuous commissioning® on the energy star® rating of hospitals and office buildings. (Master of science), Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10667

205

Kunkel, Sara, & Kontonasiou, Eleni. (2015). Indoor air quality, thermal comfort and daylight policies on the way to nzeb—status of selected ms and future policy recommendations. Paper presented at the Proceedings of the ECEEE Summer Study, First Fuel Now, Belambra Les Criques, Paris-France. http://bpie.eu/wp- content/uploads/2015/11/Indoor-air-quality-thermal-comfort-and-daylight-policies- on-the-way-to-nZEB-%E2%80%93-status-of-selected-MS-and-future-policy- recommendations.pdf Lapinskiene, Vilune, & Martinaitis, Vytautas. (2013). The framework of an optimization model for building envelope. Procedia Engineering, 57, 670-677. doi: 10.1016/j.proeng.2013.04.085 Lau, Allen Khin Kiet, Salleh, Elias, Lim, Chin Haw, & Sulaiman, Mohamad Yusof. (2016). Potential of shading devices and glazing configurations on cooling energy savings for high-rise office buildings in hot-humid climates: The case of Malaysia. International Journal of Sustainable Built Environment, 5(2), 387-399. doi: 10.1016/j.ijsbe.2016.04.004 Li, Yimin. (2011). Nanoscale advances in catalysis and energy applications. Lawrence Berkeley National Laboratory. Loonen, Roel C. G. M., Favoino, Fabio, Hensen, Jan L. M., & Overend, Mauro. (2016). Review of current status, requirements and opportunities for building performance simulation of adaptive facades. Journal of Building Performance Simulation, 1-19. doi: 10.1080/19401493.2016.1152303 Loussos, Paressa, Konstantinou, Thaleia, van den Dobbelsteen, Andy, & Bokel, Regina. (2015). Integrating life cycle energy into the design of façade refurbishment for a post- war residential building in the netherlands. Buildings, 5(2), 622. doi: 10.3390/buildings5020622 Love, J. Christopher, Estroff, Lara A., Kriebel, Jennah K., Nuzzo, Ralph G., & Whitesides, George M. (2005). Self-assembled monolayers of thiolates on metals as a form of nanotechnology. Chemical Reviews, 105(4), 1103-1170. doi: 10.1021/cr0300789 Luther, J, & Reindl, T. (2013). Solar photovoltaic (pv) roadmap for Singapore. Retrieved from https://www.nccs.gov.sg/sites/nccs/files/Roadmap_Solar_20140729.pdf. Lynch, P. M., & Hunt, G. R. (2011). The night purging of a two-storey atrium building. Building and Environment, 46(1), 144-155. doi: 10.1016/j.buildenv.2010.07.009 Ma, Zhenjun, Cooper, Paul, Daly, Daniel, & Ledo, Laia. (2012). Existing building retrofits: Methodology and state-of-the-art. Energy and Buildings, 55, 889-902. doi: 10.1016/j.enbuild.2012.08.018 Marszal, Anna Joanna, Bourrelle, Julien S, Musall, Eike, Heiselberg, Per, Gustavsen, Arild, & Voss, Karsten. (2010). Net zero energy buildings-calculation methodologies versus national building codes. the Proceedings of EuroSun. Marszal, Anna Joanna, & Heiselberg, Per. (2011). Zero energy building definition–a literature review. International Energy Agency Retrieved from http://www.iea-shc.iea-shc.iea- shc.iea-shc.org/data/sites/1/publications/T40A52-STA-Marzal-Report-2012-09.pdf. Martinez, Andrea, & Carlson, Anders. (2014). State of the art methodology to assess energy facade retrofits (EFR). Paper presented at the ARCC Conference Repository. http://arcc-journal.org/index.php/repository/article/view/290/227 Martinez, Andrea, Patterson, Mic, Carlson, Anders, & Noble, Douglas. (2015). Fundamentals in façade retrofit practice. Procedia Engineering, 118, 934-941. doi: 10.1016/j.proeng.2015.08.534 Mauro, Gerardo Maria. (2015). Multi-objectvice optimization for cost-optimal energy retrofitting: from the single building to a stock. (PhD Thesis), University of Naples Federico II. Retrieved from http://www.fedoa.unina.it/10292/1/mauro_gerardomaria_27.pdf

206

McArthur, J., Jofeh, Chris, & Aguilar, Ann-Marie. (2015). Improving occupant wellness in commercial office buildings through energy conservation retrofits. Buildings, 5(4), 1171. doi: 10.3390/buildings5041171 McCluney, Ross. (1991). The death of the shading coefficient. ASHRAE journal, 33(3), 36- 45. Mic Patterson, & Matusova, Jennie. (2013). High-performance facades. Retrieved from http://www.enclos.com/site-info/news/high-performance-facades-part-four-getting- there-metrics-best-practices. Mirrahimi, Seyedehzahra, Mohamed, Mohd Farid, Haw, Lim Chin, Ibrahim, Nik Lukman Nik, Yusoff, Wardah Fatimah Mohammad, & Aflaki, Ardalan. (2016). The effect of building envelope on the thermal comfort and energy saving for high-rise buildings in hot–humid climate. Renewable and Sustainable Energy Reviews, 53, 1508-1519. doi: 10.1016/j.rser.2015.09.055 Mirzaei, Parham A., & Haghighat, Fariborz. (2012). Modeling of phase change materials for applications in whole building simulation. Renewable and Sustainable Energy Reviews, 16(7), 5355-5362. doi: 10.1016/j.rser.2012.04.053 Mitterer, Christoph, Künzel, Hartwig M, Herkel, Sebastian, & Holm, Andreas. (2012). Optimizing energy efficiency and occupant comfort with climate specific design of the building. Frontiers of Architectural Research, 1(3), 229-235. doi: 10.1016/j.foar.2012.06.002 Mogheir, Y., de Lima, J. L. M. P., & Singh, V. P. (2009). Entropy and multi-objective based approach for groundwater quality monitoring network assessment and redesign. Water Resources Management, 23(8), 1603-1620. doi: 10.1007/s11269-008-9343-8 Molina Larraín, Germán. (2014). Integrated thermal and lighting analysis of spaces with controled complex fenestration systems and artificial lighting during the design stage. (Master of science in enginnering), Pontificia Universidad Católica de Chile. Retrieved from https://repositorio.uc.cl/handle/11534/3275 Moosavi, Leila, Mahyuddin, Norhayati, Ab Ghafar, Norafida, & Ismail, Muhammad Azzam. (2014). Thermal performance of atria: An overview of natural ventilation effective designs. Renewable and Sustainable Energy Reviews, 34, 654-670. doi: 10.1016/j.rser.2014.02.035 Mourad, MM, Ahmed Hamza, HA, Ookawara, S, & Abdel-Rahman, AK. (2014). Wind catcher earth air tunnel: A tool for passive cooling for residential home in new cites of Egypt. Paper presented at the The Fourth Asian Conference on Sustainability, Energy and the Environment ACSEE2014. https://www.researchgate.net/publication/264419527 Mudarri, David H. (2010). Building codes and indoor air quality. Retrieved from https://www.epa.gov/sites/production/files/2014- 08/documents/building_codes_and_iaq.pdf. Muhaisen, Ahmed. (2015). Effect of wall thermal properties on the energy consumption of buildings in the Gaza strip. Paper presented at the International Sustainable Buildings Symposium, Ankara-Turkiya. http://www.isbs2015.gazi.edu.tr/belgeler/bildiriler/1013-1020.pdf Muhsin, Fakhriah, Mohammad Yusoff, Wardah Fatimah, Mohamed, Mohd Farid, & Sapian, Abdul Razak. (2016). The Effects of Void on Natural Ventilation Performance in Multi-Storey Housing. Buildings, 6(3), 35. Napier, John. (2015). Climate based façade design for business buildings with examples from central London. Buildings, 5(1), 16. doi: 10.3390/buildings5010016 Oh, Jeongyoon, Hong, Taehoon, Kim, Hakpyeong, An, Jongbaek, Jeong, Kwangbok, & Koo, Choongwan. (2017). Advanced strategies for net-zero energy building: Focused on the early phase and usage phase of a building’s life cycle. Sustainability, 9(12), 2272. doi: 10.3390/su9122272

207

Omar, Osama, & Sabsaby, Yathreb. (2014). Paths towards zero carbon city using nanotechnology. Paper presented at the World SB 14, Barcelona. http://www.academia.edu/download/35489725/PATHS_TOWARDS_ZERO_CARB ON_CITY_USING_NANOTECHNOLOGY.pdf Ottelé, Marc, Perini, Katia, Fraaij, A. L. A., Haas, E. M., & Raiteri, R. (2011). Comparative life cycle analysis for green façades and living wall systems. Energy and Buildings, 43(12), 3419-3429. doi: 10.1016/j.enbuild.2011.09.010 Palestine Energy and Natural Resources Authority. (2012). Reasons of current energy crisis. Retrieved 14-11, 2012, from http://www.penra.gov.ps/index.php?option=com_content&view=article&id=760:201 2-11-14-09-46-28&catid=27:2012-11-14-08-37-30&Itemid=61 Parra, Jordi, Guardo, Alfredo, Egusquiza, Eduard, & Alavedra, Pere. (2015). Thermal performance of ventilated double skin façades with venetian blinds. Energies, 8(6), 4882-4898. doi: 10.3390/en8064882 Patterson, Mic, Vaglio, Jeffrey, & Noble, Douglas. (2014). Incremental façade retrofits: Curtainwall technology as a strategy to step existing buildings toward zero net energy. Energy Procedia, 57, 3150-3159. doi: 10.1016/j.egypro.2015.06.061 PEC. (2004). Energy efficient buildings code: Ministry of Local Government,. Peng, Jinqing, Lu, Lin, Yang, Hongxing, & Han, Jun. (2013). Investigation on the annual thermal performance of a photovoltaic wall mounted on a multi-layer façade. Applied Energy, 112, 646-656. doi: 10.1016/j.apenergy.2012.12.026 Pereira, Ricardo Jorge da Silva. (2015). Design and optimization of building integration PV/T systems (BIPV/T). (Master thesis), Universidade de Évora. Retrieved from http://hdl.handle.net/10174/13382 Pérez, Gabriel, Coma, Julià, Martorell, Ingrid, & Cabeza, Luisa F. (2014). Vertical Greenery Systems (VGS) for energy saving in buildings: A review. Renewable and Sustainable Energy Reviews, 39, 139-165. doi: https://doi.org/10.1016/j.rser.2014.07.055 Perini, Katia, Ottelé, Marc, Fraaij, A. L. A., Haas, E. M., & Raiteri, Rossana. (2011). Vertical greening systems and the effect on air flow and temperature on the building envelope. Building and Environment, 46(11), 2287-2294. doi: http://dx.doi.org/10.1016/j.buildenv.2011.05.009 Perlova, Elena, Platonova, Mariia, Gorshkov, Alexandr, & Rakova, Xenyiya. (2015). Concept project of zero energy building. Procedia Engineering, 100, 1505-1514. doi: 10.1016/j.proeng.2015.01.522 Petersen, Rasmus Helveg. (2014). Danish government: Strategy for energy renovation of buildings: The route to energy-efficient buildings in tomorrow’s denmark. Danish Government Retrieved from https://ec.europa.eu/energy/sites/ener/files/documents/2014_article4_en_denmark.pd f. Petter Jelle, Bjørn, Breivik, Christer, & Drolsum Røkenes, Hilde. (2012). Building integrated photovoltaic products: A state-of-the-art review and future research opportunities. Solar Energy Materials and Solar Cells, 100, 69-96. doi: 10.1016/j.solmat.2011.12.016 Pless, Shanti D, & Torcellini, Paul Allen. (2010). Net-zero energy buildings: A classification system based on renewable energy supply options. National Renewable Energy Laboratory Retrieved from https://www.nrel.gov/docs/fy10osti/44586.pdf. Pomponi, Francesco, & Piroozfar, Poorang AE. (2015). Double skin façade (DSF) technologies for UK office refurbishments: A systemic matchmaking practice. Structural Survey, 33(4/5), 372-406. doi: 10.1108/SS-04-2015-0025 Prades Villanova, Marc. (2013). Vertical farm façade: First approach to the energetic savings applied to the seagram building in New York. (Master thesis), Escola de Camins Canals. Retrieved from

208

https://upcommons.upc.edu/bitstream/handle/2099.1/23367/Vertical%20Farm%20Fa %C3%A7ade%20(Marc%20Prades).pdf Principi, Paolo, & Fioretti, Roberto. (2012). Thermal analysis of the application of PCM and low emissivity coating in hollow bricks. Energy and Buildings, 51, 131-142. doi: 10.1016/j.enbuild.2012.04.022 Purohit, Kuldeep, Khitoliya, Pooja, & Purohit, Rajesh. (2011). Recent advances in nanotechnology. Paper presented at the 21st World Nanotechnology Congress, Dubai, UAE. https://www.omicsonline.org/conferences-list/recent-advances-in- nanotechnology Quesada, Guillermo, Rousse, Daniel, Dutil, Yvan, Badache, Messaoud, & Hallé, Stéphane. (2012a). A comprehensive review of solar facades. Opaque solar facades. Renewable and Sustainable Energy Reviews, 16(5), 2820-2832. doi: 10.1016/j.rser.2012.01.078 Quesada, Guillermo, Rousse, Daniel, Dutil, Yvan, Badache, Messaoud, & Hallé, Stéphane. (2012b). A comprehensive review of solar facades. Transparent and translucent solar facades. Renewable and Sustainable Energy Reviews, 16(5), 2643-2651. doi: 10.1016/j.rser.2012.02.059 Rabou, Abdel Fattah N. Abd. (2011). Notes on some Palestinian bird fauna existing in the. American Eurasian Jornal, Agric.&Environ Science, 11(2), 159-172. Raffio, Gregory, Mento, Chris, Seryak, John, Kleinhenz, Peter, Schreier, Charles, Tatari, Mohamed, & Sever, Franc. (2012). Feasibility study for a net-zero energy campus retrofit. Raji, Babak, Tenpierik, Martin J, & Van den Dobbelsteen, AAJF. (2014). A comparative study of design strategies for energy efficiency in 6 high-rise buildings in two different climates. Paper presented at the PLEA 2014: Proceedings of the 30th International PLEA Conference, Ahmedabad, India. http://www.plea2014.in/wp- content/uploads/2014/12/Paper_2A_2319_PR.pdf Riffat, Saffa B., & Qiu, Guoquan. (2012). A review of state-of-the-art aerogel applications in buildings. International Journal of Low-Carbon Technologies, 8(1), 1-6. doi: 10.1093/ijlct/cts001 Rivera, Eric. (2014). Quantifying Co2 removal by living walls: A case study of the center for design research. Journal of Undergraduate Research. Rocky Mountain Institute. (2017). How-to guide: Net zero retrofit technical and cost benchmark studies. Retrieved from https://rmi.org/wp- content/uploads/2017/09/RMI_Techno_Economic_Study_How_To_Guide.pdf. Rysanek, A. M., & Choudhary, R. (2013). Optimum building energy retrofits under technical and economic uncertainty. Energy and Buildings, 57, 324-337. doi: 10.1016/j.enbuild.2012.10.027 Šadauskiene, Jolanta, Buska, Andrius, Burlingis, Arūnas, Bliūdžius, Raimondas, & Gailius, Albinas. (2009). The effect of vertical air gaps to thermal transmittance of horizontal thermal insulating layer. Journal of Civil Engineering and Management, 15(3), 309- 315. doi: 10.3846/1392-3730.2009.15.309-315 Safi, Samir, Migdad, Mohammed Ibrahim, & tawil, fadi. (2014). Building multiple regression model for electricity consumption in Gaza strip. IUG Journal of Natural and Engineering Studies, 22(1), 1:1-1:24. Safikhani, Tabassom, Abdullah, Aminatuzuhariah Megat, Ossen, Dilshan Remaz, & Baharvand, Mohammad. (2014). Thermal impacts of vertical greenery systems. Environmental and Climate Technologies, 14(1), 5-11. doi: 10.1515/rtuect-2014-0007 Samaan, Mina Michel, Farag, Osama, & Khalil, Magdi. (2016). Using simulation tools for optimizing cooling loads and daylighting levels in Egyptian campus buildings. HBRC Journal. doi: 10.1016/j.hbrcj.2016.01.001

209

Sanchez, E, Rolando, A, Sant, R, & Ayuso, L. (2016). Influence of natural ventilation due to buoyancy and heat transfer in the energy efficiency of a double skin facade building. Energy for Sustainable Development, 33, 139-148. doi: 10.1016/j.esd.2016.02.002 Sang, Xiaoxia, Pan, Wei, & Kumaraswamy, M. M. (2014). Informing energy-efficient building envelope design decisions for hong kong. Energy Procedia, 62, 123-131. doi: 10.1016/j.egypro.2014.12.373 Sanguinetti, Paola. (2012). Integrated performance framework to guide façade retrofit. (Doctoral thesis), Georgia Institute of Technology. Retrieved from https://smartech.gatech.edu/handle/1853/45814 Santamouris, Mat, & Kolokotsa, Denia (Eds.). (2016). Urban climate mitigation techniques. https://books.google.ps/books?id=RrxYCwAAQBAJ&printsec=frontcover Sapian, Abdul Razak, Majid, Abdul, Hanita, Noor, & Hokoi, Shuichi. (2012). Natural ventilation around open round floors with pilotis in high-rise residential buildings in tropical areas: harmonization of modern and traditional housing in tropical areas. Paper presented at the 2nd International Conference, Mukogawa Women’s Univ., Nishinomiya, Japan, . http://www.mukogawa- u.ac.jp/~iasu2012/pdf/iaSU2012_Proceedings_406.pdf Sartori, Igor, Napolitano, Assunta, Marszal, Anna Joanna, Pless, Shanti, Torcellini, Paul, & Voss, Karsten. (2010). Criteria for definition of net zero energy buildings. Paper presented at the International Conference on Solar Heating, Cooling and Buildings (EuroSun 2010). http://vbn.aau.dk/ws/files/43736193/Criteria_for_Definition_of_Net_Zero_Energy_ Buildings.pdf Sartori, Igor, Napolitano, Assunta, & Voss, Karsten. (2012). Net zero energy buildings: A consistent definition framework. Energy and Buildings, 48, 220-232. doi: 10.1016/j.enbuild.2012.01.032 Sbar, Neil L., Podbelski, Lou, Yang, Hong Mo, & Pease, Brad. (2012). Electrochromic dynamic windows for office buildings. International Journal of Sustainable Built Environment, 1(1), 125-139. doi: 10.1016/j.ijsbe.2012.09.001 Sebestyen, Gyula. (2003). New architecture and technology. Architectural Press. https://www.routledge.com/New-Architecture-and-Technology/Sebestyen- Pollington/p/book/9780750651646 Serghides, D. K., Dimitriou, S., Katafygiotou, M. C., & Michaelidou, M. (2015). Energy efficient refurbishment towards nearly zero energy houses, for the mediterranean region. Energy Procedia, 83, 533-543. doi: 10.1016/j.egypro.2015.12.173 Sharma, Sunil Kumar. (2013). Zero Energy Building Envelope Components: A Review. International Journal of Engineering Research and Applications (IJERA), 3(2), 662- 675. Sheweka, Samar Mohamed, & Mohamed, Nourhan Magdy. (2012). Green facades as a new sustainable approach towards climate change. Energy Procedia, 18, 507-520. doi: 10.1016/j.egypro.2012.05.062 Silva, Tiago, Vicente, Romeu, Soares, Nelson, & Ferreira, Victor. (2012). Experimental testing and numerical modelling of masonry wall solution with PCM incorporation: A passive construction solution. Energy and Buildings, 49, 235-245. doi: 10.1016/j.enbuild.2012.02.010 Soares, N., Costa, J. J., Gaspar, A. R., & Santos, P. (2013). Review of passive PCM latent heat thermal energy storage systems towards buildings’ energy efficiency. Energy and Buildings, 59, 82-103. doi: 10.1016/j.enbuild.2012.12.042 Spentzou, Eftychia, Cook, Malcolm J, & Emmitt, Stephen. (2014). Assessing natural cooling strategies in apartment buildings using de-coupled internal-external airflow simulations. Paper presented at the Architecture, Building and Civil Engineering, U.K. https://dspace.lboro.ac.uk/2134/19314

210

Staljanssens, Joni, Mangé, Stéphanie, Van Den Bossche, Nathan, & Moens, Jan. (2015). Façade retrofit strategies. Case study of the building complex k12 of the university hospital Ghent. Energy Procedia, 78, 961-966. doi: 10.1016/j.egypro.2015.11.032 State of Palestine. (2016a). Palestine: Palestinian central bureau of statistics,Palestinian Citizen circumstances in Palestine. Retrieved from http://www.pcbs.gov.ps/Downloads/book2207.pdf. State of Palestine. (2016b). Palestinian central bureau of statistics. Retrieved from http://www.pcbs.gov.ps/site/lang__ar/881/default.aspx#Geography&ClimateConditi onsA. State of palestine. (2016c). Palestinian central bureau of statistics, the renewable energy sources in Palestine. Retrieved from http://www.pcbs.gov.ps/Downloads/book2169.pdf. Steskens, P., Vanhellemont, Y., Roels, S., & Van Den Bossche, N. (2015). A Decision Making Tool for the Energy Efficient Refurbishment of Residential Buildings. Energy Procedia, 78, 997-1002. doi: 10.1016/j.egypro.2015.11.043 Taleb, Hanan M. (2014). Using passive cooling strategies to improve thermal performance and reduce energy consumption of residential buildings in U.A.E. buildings. Frontiers of Architectural Research, 3(2), 154-165. doi: 10.1016/j.foar.2014.01.002 Thabit, Ahmad Mohamad Jbril. (2011). The climate and its impact on human comfort and health In West Bank and Gaza Strip - Palestine. (Master thesis), Islamic University. Retrieved from http://library.iugaza.edu.ps/thesis.aspx The Coalition for Energy Savings. (2013). EU Energy Efficiency Directive (2012/27/EU), guidebook for strong implementation. Retrieved from http://bpie.eu/wp- content/uploads/2015/10/Guidebook-for-strong-implementation.pdf. The National Institute of Building Sciences. (2015). A common definition for zero energy buildings. Retrieved from http://energy.gov/sites/prod/files/2015/09/f26/bto_common_definition_zero_energy_ buildings_093015.pdf. The World Bank. (2016). West bank & Gaza, energy efficiency action plan 2020-2030. Retrieved from http://documents.worldbank.org/curated/en/851371475046203328/pdf/ACS19044- REPLACEMENT-PUBLIC-FINAL-REPORT-P147961-WBGaza-Energy- Efficiency-Action-Plan.pdf. Torcellini, Paul, Pless, Shanti, Deru, Michael, & Crawley, Drury. (2006). Zero energy buildings: a critical look at the definition. US: Retrieved from http://www.biomassthermal.org/programs/documents/118_ZEBCriticalLookDefiniti on.pdf. U.S. energy Information Administration. (2016). International energy outlook 2016. International Energy Agency Retrieved from https://www.eia.gov/forecasts/ieo/pdf/0484(2016).pdf. UK building regulations and EU directives. (2014). Zero carbon homes and nearly zero energy buildings. London: UK Building Regulations and EU Directives Retrieved from http://www.zerocarbonhub.org/sites/default/files/resources/reports/ZCHomes_Nearl y_Zero_Energy_Buildings.pdf. University of California. (2013). Sustainable practices. Retrieved from http://policy.ucop.edu/doc/3100155/Sustainable%20Practices. Uribe, Oscar, Martin, Juan, Garcia-Alegre, María, Santos, Matilde, & Guinea, Domingo. (2015). Smart building: Decision making architecture for thermal energy management. Sensors, 15(11), 27543. doi: 10.3390/s151127543 Van Den Engel, Peter, & Kemperman, Remco. (2012). Natural and hybrid ventilation principles based on buoyancy, sun and wind. REHVA Journal, 25-32.

211

Waide, Paul, Guertler, Pedro, & Smith, Winton. (2006). High-rise refurbishment: The energy- efficient upgrade of multi-story residences in the European Union. International Energy Agency Retrieved from https://www.iea.org/publications/freepublications/publication/pw_Highrise.pdf. Wang, Jinbo, Du, Qianzhou, Zhang, Chong, & Xu, Xinhua. (2017). Energy Performance of Triple Glazed Window with Built-in Venetian Blinds by Utilizing Forced Ventilated airflow. Procedia Engineering, 205(Supplement C), 3993-4000. doi: 10.1016/j.proeng.2017.09.865 Wikipedia. (2016a). Köppen climate classification. Wikipedia. (2016b). Zero-energy building. Wittkopf, Stephen. (2015). tropical net zero. Singapore: High Performing Buildings Retrieved from http://www.hpbmagazine.org/attachments/article/12186/15S-Zero-Energy- Building-BCA-Academy-Singapore.pdf. Xu, Pengpeng, Chan, Edwin H. W., Visscher, Henk J., Zhang, Xiaoling, & Wu, Zezhou. (2015). Sustainable building energy efficiency retrofit for hotel buildings using EPC mechanism in China: analytic Network Process (ANP) approach. Journal of Cleaner Production, 107, 378-388. doi: http://dx.doi.org/10.1016/j.jclepro.2014.12.101 Zhang, Xingxing, Shen, Jingchun, Hong, Zehui, Wang, Luying, Yang, Tong, Tang, Llewellyn, . . . Xu, Peng. (2015). Building integrated solar thermal (BIST) technologies and their applications: A review of structural design and architectural integration. Journal of Fundamentals of Renewable Energy and Applications, 2015. doi: 10.4172/2090-4541.1000182 Zhang, Yinping, Zhou, Guobing, Lin, Kunping, Zhang, Qunli, & Di, Hongfa. (2007). Application of latent heat thermal energy storage in buildings: State-of-the-art and outlook. Building and Environment, 42(6), 2197-2209. doi: 10.1016/j.buildenv.2006.07.023 Zuhaib, Sheikh, Hajdukiewicz, Magdalena, Keane, Marcus M, & Goggins, Jamie. (2016). Generic assessment of optimisation methods for performance based design of retrofitted building façades for nearly zero-energy buildings. Paper presented at the Conference Proceedings of the 10th Energy Forum. https://www.researchgate.net/publication/301296772

212

1. Appendix (01)

Table (appx 1.1): Thermal properties of the existing construction elements of QEAB

floorsfloors floors EXT-20EXT-20 cm wall cm wall EXT-20 cm wall part-20part-20 cm wall cm wall part-20 cm wall RC-20RC-20 cm wall cm wall RC-20 cm wall thicknessthicknessDensitythicknessDensity SpDensitySpConductivity ConductivitySp Conductivity thicknessthicknessDensityDensity thickness Sp SpConductivityDensityConductivity Sp Conductivity thicknessthicknessDensityDensity Sp SpConductivitythicknessConductivityDensity Sp Conductivity thicknessthicknessDensityDensity Sp SpConductivityConductivitythickness Density Sp Conductivity N/SOURCEN/SOURCEmatrialsN/SOURCEmatrials matrials N/SOURCEN/SOURCEmatrialsmatrialsN/SOURCE matrials N/SOURCEN/SOURCEmatrialsmatrials N/SOURCE matrials N/SOURCEN/SOURCEmatrialsmatrials N/SOURCE matrials mm mm Kg/m3Kg/m3mm J/Kg.KJ/Kg.KKg/m3W/m.kW/m.kJ/Kg.K W/m.k mm mm Kg/m3Kg/m3 J/Kg.KmmJ/Kg.K W/m.kKg/m3W/m.k J/Kg.K W/m.k mm mm Kg/m3Kg/m3J/Kg.KJ/Kg.KW/m.kmmW/m.kKg/m3 J/Kg.K W/m.k mm mm Kg/m3Kg/m3J/Kg.KJ/Kg.KW/m.kW/m.kmm Kg/m3 J/Kg.K W/m.k 1/ECO Porcelain 12 3400 753.1 2.092 2.5 1/PCODE plaster 30 2000 1000 1.2 1.4 1/PCODE plaster 20 2000 1000 1.2 0.35 1/PCODE plaster 20 2000 1000 1.2 0.35 1/ECO 1/ECOPorcelain Porcelain12 340012 753.13400 2.092753.1 2.52.092 2.5 1/PCODE plaster1/PCODE30 plaster2000 30 1000 20001.2 10001.4 1.2 1/PCODE1.4 plaster 201/PCODE2000plaster1000 20 1.2 20000.35 1000 1/PCODE1.2 0.35plaster 20 1/PCODE2000 plaster1000 1.220 0.352000 1000 1.2 0.35 2/ECO mortor 20 1650 920 0.72 2.2 2/PCODE conc. Block 200 1400 1000 0.9 2/PCODE conc. Block 200 1400 1000 0.9 2/PCODE RC 200 2300 1000 1.75 2/ECO 2/ECOmortor mortor20 165020 9201650 0.72920 2.20.72 2.2 2/PCODE conc. Block2/PCODE200conc. Block1400 2001000 14000.9 1000 0.9 2/PCODE conc. Block 2002/PCODE1400conc. Block1000 200 0.9 1400 1000 2/PCODE0.9 RC 200 2/PCODE2300 1000RC 1.75200 2300 1000 1.75 3/ECO sand 50 2240 840 1.74 1.75 3/PCODE plaster 20 2000 1000 1.2 1.4 3/PCODE plaster 20 2000 1000 1.2 0.35 3/PCODE plaster 20 2000 1000 1.2 0.35 3/ECO 3/ECOsand sand50 224050 8402240 1.74840 1.751.74 1.75 3/PCODE plaster3/PCODE20 plaster2000 20 1000 20001.2 10001.4 1.2 3/PCODE1.4 plaster 203/PCODE2000plaster1000 20 1.2 20000.35 1000 3/PCODE1.2 0.35plaster 20 3/PCODE2000 plaster1000 1.220 0.352000 1000 1.2 0.35 4/PCODE4/PCODEconcreteconcrete 70 70 25002500 10001000 1.751.75 ECTOTECTECTOTECT 2.262.26 2.292.29 ECTOTECTECTOTECT 2.312.31 1.941.94 ECTOTECTECTOTECT 3.073.07 2.462.46 4/PCODE concrete 70 2500 1000 1.75 U valueU value W/m2.K W/m2.K ECTOTECT 2.26 U valueU2.29 value W/m2.K W/m2.K ECTOTECT 2.31U valueU value W/m2.K W/m2.K1.94 ECTOTECT 3.07 2.46 5/PCODE5/PCODE rebisrebis 180 180 14001400 10001000 0.950.95 U valueDesignBuilderDesignBuilder W/m2.K 2.3 2.3 DesignBuilderDesignBuilderU value W/m2.K 1.941.94 DesignBuilderDesignBuilderU value W/m2.K2.452.45 5/PCODE rebis 180 1400 1000 0.95 DesignBuilder 2.3 DesignBuilder 1.94 DesignBuilder 2.45 6/ECO6/ECO plasterplaster 20 20 19001900 840 840 1.5 1.5 1.2 1.2 6/ECO plaster 20 1900 840 1.5 1.2 7/ECO7/ECO AIR gapAIR gap 15 15 1.3 1.3 10041004 5.565.56 12 12 7/PCODE7/PCODEGYPUM7/ECOGYPUM 0.05AIR0.05 gap 1000100015 940 9401.3 0.2 0.21004 0.420.425.56 12 7/PCODE GYPUMECTOTECT 0.05 10001.46 940 1.74 0.2 0.42 EXT-15 cm wall part-15cm wall U value W/m2.K ECTOTECT 1.46 1.74 EXT-15 cm wall part-15cm wall U value W/m2.K DesignBuilder ECTOTECT1.74 1.46 1.74 thickness Density EXT-15Sp Conductivitycm wall thickness Density Sp Conductivitypart-15cm wall U value W/m2.KDesignBuilder 1.74 N/SOURCE matrials thickness Density Sp Conductivity N/SOURCE matrials thickness Density Sp Conductivity DesignBuilder 1.74 N/SOURCE matrials mm Kg/m3 thicknessJ/Kg.K DensityW/m.k Sp Conductivity N/SOURCE matrialsmm Kg/m3 J/Kg.K thicknessW/m.k Density Sp Conductivity N/SOURCEmm matrialsKg/m3 J/Kg.K W/m.k mmN/SOURCEKg/m3matrialsJ/Kg.K W/m.k RoofRoof 1/PCODE1/PCODEplasterplaster 30 30 20002000 1000mm1000 Kg/m31.2 1.2 J/Kg.K1.4 1.4 W/m.k 1/PCODE1/PCODEplasterplaster 20 20 20002000 10001000 mm1.2 1.2 Kg/m30.350.35 J/Kg.K W/m.k thicknessthicknessDensityDensity RoofSp SpConductivityConductivity 2/PCODE2/PCODEconc.conc. Block Block1/PCODE150 150 plaster14001400 100030 1000 20000.9 0.9 1000 1.2 2/PCODE2/PCODE1.4conc.conc. Block Block150 1501/PCODE14001400plaster10001000 200.9 0.9 2000 1000 1.2 0.35 N/SOURCEN/SOURCEmatrialsmatrials mm mm Kg/m3thicknessKg/m3 J/Kg.KDensityJ/Kg.K W/m.k W/m.kSp Conductivity 3/PCODE3/PCODEplasterplaster2/PCODE20 20conc.2000 Block2000 10001501000 14001.2 1.2 1.410001.4 0.9 3/PCODE3/PCODEplasterplaster 20 202/PCODE20002000conc.1000 Block1000 1501.2 1.2 14000.350.35 1000 0.9 1/PCODE w.membraneN/SOURCE 20matrials 2300 1000 1.1 0.35 ECTOTECT 2.59 2.63 ECTOTECT 2.65 2.18 1/PCODE w.membrane 20 2300mm Kg/m31000 J/Kg.K1.1 0.35W/m.k U value W/m2.K 3/PCODE ECTOTECTplaster 20 2.592000 10002.63 1.2 U value1.4 W/m2.K 3/PCODEECTOTECT plaster 2.6520 20002.18 1000 1.2 0.35 U value W/m2.K DesignBuilder 2.64 U value W/m2.K DesignBuilder 2.17 2/PCODE2/PCODEscreed1/PCODEscreed w.membrane80 80 2300230020 100010002300 1.751.751000 1.1 0.35 DesignBuilder ECTOTECT2.64 2.59 2.63 DesignBuilder 2.17ECTOTECT 2.65 2.18 4/PCODE concrete 70 2500 1000 1.75 U value W/m2.K U value W/m2.K 4/PCODE 2/PCODEconcrete screed70 250080 10002300 1.751000 1.75 DesignBuilder 2.64 DesignBuilder 2.17 5/PCODE rebis 180 1400 1000 0.95 part-10cm wall 5/PCODE 4/PCODErebis concrete180 140070 10002500 0.951000 1.75 part-10cm wall 6/PCODE plaster 20 2000 1000 1.2 thickness Density Sp Conductivity 6/PCODE 5/PCODEplaster rebis20 2000180 10001400 1.21000 0.95 thickness Density Sp part-10cmConductivity wall 7/ECO7/ECO AIR gapAIR gap 15 15 1.3 1.3 10041004 5.565.56 5.3 5.3 N/SOURCEN/SOURCEmatrialsmatrials 6/PCODE plaster 20 2000 1000 1.2 thickness Density Sp Conductivity 7/PCODE7/PCODEGYPUMGYPUM 0.050.05 10001000 940 940 0.2 0.2 0.5 0.5 mm mm Kg/m3Kg/m3J/Kg.KJ/Kg.KW/m.kW/m.k 7/ECO AIRECTOTECT gap 15 1.31.45 1004 1.36 5.56 5.3 glazing 1/PCODE plaster 20 N/SOURCE2000 matrials1000 1.2 0.35 U value W/m2.K ECTOTECT 1.45 1.36 glazing 1/PCODE plaster 20 2000 1000 1.2 0.35 BASELINE CASE PROPERTIES U value 7/PCODEW/m2.K DesignBuilderGYPUM 0.05 10001.36 940 0.2 0.5 thickness Density Sp Conductivity 2/PCODE conc. Block 100 1400 1000 mm0.9 Kg/m3 J/Kg.K W/m.k BASELINE CASE PROPERTIES DesignBuilder 1.36 N/SOURCE matrials thickness Density Sp Conductivity 2/PCODE conc. Block 100 1400 1000 0.9 ECTOTECT 1.45 1.36 N/SOURCE matrials glazing 1/PCODE plaster 20 2000 1000 1.2 0.35 U value W/m2.K mm mm Kg/m3Kg/m3 J/Kg.KJ/Kg.K W/m.kW/m.k 3/PCODE3/PCODEplasterplaster 20 20 20002000 10001000 1.2 1.2 0.350.35 BASELINE CASE PROPERTIES DesignBuilder 1.36 1/PCODE1/PCODE glazzglazz 6 6 23002300 thickness836.8836.8 Density1.051.05 Sp Conductivity ECTOTECT2/PCODEECTOTECTconc. Block3.1 1003.1 14002.482.48 1000 0.9 N/SOURCE matrials U valueU value W/m2.K W/m2.K mm Kg/m3 J/Kg.K W/m.k DesignBuilderDesignBuilder3/PCODE plaster 2.472.4720 2000 1000 1.2 0.35 1/PCODE glazz 6 2300 836.8 1.05 ECTOTECT 3.1 2.48 U value W/m2.K floors 385.05385.05 EXT-20 cm wall ECTOTECTECTOTECTpart-20 cm wall 6 6 5.8 5.8 RC-20 cm wall DesignBuilder 2.47 U valueU value W/m2.K W/m2.K thickness Density Sp Conductivity thickness Density Sp Conductivity DesignBuilderDesignBuilderthickness Density Sp6 6Conductivity thickness Density Sp Conductivity N/SOURCE matrials N/SOURCE matrials N/SOURCE matrials N/SOURCE matrials mm Kg/m3 J/Kg.K W/m.k 385.05 mm Kg/m3 J/Kg.K W/m.k mm Kg/m3 ECTOTECTJ/Kg.K W/m.k 6 5.8 mm Kg/m3 J/Kg.K W/m.k U value W/m2.K 1/ECO Porcelain 12 3400 753.1 2.092 2.5 1/PCODE plaster 30 2000 1000 1.2 1.4 1/PCODE plaster 20 2000 DesignBuilder1000 1.2 0.35 6 1/PCODE plaster 20 2000 1000 1.2 0.35 2/ECO mortor 20 1650 920 0.72 2.2 2/PCODE conc. Block 200 1400 1000 0.9 2/PCODE conc. Block 200 1400 1000 0.9 2/PCODE RC 200 2300 1000 1.75 3/ECO sand 50 2240 840 1.74 1.75 3/PCODE plaster 20 2000 1000 1.2 1.4 3/PCODE plaster 20 2000 1000 1.2 0.35 3/PCODE plaster 20 2000 1000 1.2 0.35 4/PCODE concrete 70 2500 1000 1.75 ECTOTECT 2.26 2.29 ECTOTECT 2.31 1.94 ECTOTECT 3.07 2.46 U value W/m2.K U value W/m2.K U value W/m2.K 5/PCODE rebis 180 1400 1000 0.95 DesignBuilder 2.3 DesignBuilder 1.94 DesignBuilder 2.45 6/ECO plaster 20 1900 840 1.5 1.2 7/ECO AIR gap 15 1.3 1004 5.56 12 7/PCODE GYPUM 0.05 1000 940 0.2 0.42 ECTOTECT 1.46 1.74 EXT-15 cm wall part-15cm wall U value W/m2.K DesignBuilder 1.74 thickness Density Sp Conductivity thickness Density Sp Conductivity N/SOURCE matrials N/SOURCE matrials mm Kg/m3 J/Kg.K W/m.k mm Kg/m3 J/Kg.K W/m.k Roof 1/PCODE plaster 30 2000Table1000 (appx1.2 1.21.4): Shading1/PCODE coefficientplaster 20 2000of the1000 examined1.2 0.35 fenestrations thickness Density Sp Conductivity 2/PCODE conc. Block 150 1400 1000 0.9 2/PCODE conc. Block 150 1400 1000 0.9 N/SOURCE matrials mm Kg/m3 J/Kg.K W/m.k 3/PCODE plaster 20 2000 1000 1.2 1.4 3/PCODE plaster 20 2000 1000 1.2 0.35 1/PCODE w.membrane 20 2300 1000 1.1 0.35 ECTOTECT 2.59 2.63 ECTOTECT 2.65 2.18 U value W/m2.K U value W/m2.K 2/PCODE screed 80 2300 1000 1.75 DesignBuilder 2.64 DesignBuilder 2.17 4/PCODE concrete 70 2500 1000 1.75 W1 W2 W3 W4 W5 5/PCODE rebis 180 1400 1000 0.95 zones part-10cm wall 6/PCODE plaster 20 2000 1000 1.2 thickness Density Sp Conductivity 7/ECO AIR gap 15 1.3 1004 5.56 5.3 LOCAL SHADING SCG SCS SCF SCG SCN/SOURCES matrialsSCF SCG SCS SCF SCG SCS SCF SCG SCS SCF 7/PCODE GYPUM 0.05 1000 940 0.2 0.5 mm Kg/m3 J/Kg.K W/m.k ECTOTECT 1.45 1.36 glazing 1/PCODE plaster 20 2000 1000 1.2 0.35 U value W/m2.K BASELINE CASE PROPERTIES DesignBuilder 1.36 0.3 OHthickness Density0.85 0.84Sp Conductivity0.71 0.85 0.842/PCODE conc.0.71 Block 1000.85 1400 0.841000 0.720.9 0.89 0.84 0.75 0.89 0.84 0.74 N/SOURCE matrials mm Kg/m3 J/Kg.K W/m.k 3/PCODE plaster 20 2000 1000 1.2 0.35 1/PCODE glazz 6 2300 836.8 1.05 ECTOTECT 3.1 2.48 U value W/m2.K 0.3 SF+OH 0.82 0.79 0.65 0.82 0.79 0.65 DesignBuilder0.81 0.75 2.470.62 0.84 0.75 0.64 0.88 0.79 0.69 L05 NE 385.05 ECTOTECT 6 5.8 U value W/m2.K 0.5 OH DesignBuilder0.76 0.73 6 0.55 0.76 0.73 0.56 0.77 0.73 0.56 0.84 0.73 0.61 0.81 0.73 0.60 0.5 SF+OH 0.71 0.68 0.48 0.70 0.68 0.48 0.69 0.65 0.45 0.73 0.65 0.47 0.78 0.68 0.53 0.3 OH 0.84 0.84 0.71 0.84 0.84 0.71 0.84 0.84 0.71 0.90 0.84 0.76 0.89 0.84 0.75 0.3 SF+OH 0.83 0.79 0.66 0.83 0.79 0.66 0.83 0.75 0.63 0.86 0.75 0.65 0.88 0.79 0.69 L05 NW 0.5 OH 0.73 0.73 0.54 0.73 0.73 0.53 0.74 0.73 0.54 0.84 0.73 0.62 0.83 0.73 0.61 0.5 SF+OH 0.72 0.68 0.49 0.71 0.68 0.48 0.70 0.65 0.46 0.74 0.65 0.48 0.78 0.68 0.53 0.3 OH 0.85 0.84 0.71 0.85 0.84 0.71 0.85 0.84 0.72 0.82 0.84 0.69 0.82 0.84 0.69 0.3 SF+OH 0.82 0.79 0.65 0.82 0.79 0.65 0.83 0.75 0.62 0.81 0.75 0.61 0.81 0.79 0.64 L05 SE 0.5 OH 0.76 0.73 0.55 0.76 0.73 0.55 0.77 0.73 0.56 0.70 0.73 0.51 0.69 0.73 0.51 0.5 SF+OH 0.70 0.68 0.47 0.70 0.68 0.47 0.68 0.65 0.44 0.67 0.65 0.43 0.68 0.68 0.46 0.3 OH 0.84 0.84 0.71 0.84 0.84 0.71 0.84 0.84 0.71 0.85 0.84 0.71 0.84 0.84 0.71 0.3 SF+OH 0.83 0.79 0.65 0.83 0.79 0.65 0.83 0.75 0.63 0.81 0.75 0.61 0.81 0.79 0.64 L05 SW 0.5 OH 0.84 0.73 0.62 0.84 0.73 0.62 0.84 0.73 0.62 0.82 0.73 0.60 0.82 0.73 0.60 0.5 SF+OH 0.71 0.68 0.48 0.71 0.68 0.48 0.70 0.65 0.45 0.67 0.65 0.43 0.67 0.68 0.46

0.8-0.7 N 0.7-0.6 E 0.6-0.5 S 0.5-0.4 W

213

5 MWh

0.8… 0.5…

ALL

EXC

1 Ohs 1

IN-BLs

10ᵒ LO 10ᵒ LO 30ᵒ LO 40ᵒ LO 60ᵒ

FRAME

0.8TOP…

0.5 Ohs 0.5

0.5TYP2 0.8TYP2

0.5TOP0 0.8TOP0 OUT-BLs

L01-SW L04-SW L08-SW

Figure (appx 1.1): General results of energy package measures

RC FRAME EXC IN-BLs OUT-BLs 0.5 Ohs 1 Ohs 10ᵒ LO 30ᵒ LO 40ᵒ LO 60ᵒ LO 0.5 OHs+SFs 0.8 OHs+SFs 0.5TOP0 0.8TOP0 0.8TOP0.7 0.5TYP2 0.8TYP2 9 8 7 6 5

MWH 4 3 2 1 0 AHL ACL AHL ACL AHL ACL L 0 1 - SW L 0 4 - SW L 0 8 - SW

Figure (appx1.2): Cumulative results of energy package measures

45.00 30.00

30.00 ᵒC ᵒC 15.00 15.00

0.00 0.00

winter winter winter winter winter winter winter winter winter winter winter winter

summer summer summer summer summer… summer summer summer summer summer summer summer… summer summer

winter 24On winter 24On winter

summer 24On summer 24On summer

winter scheduled… winter scheduled… winter RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC SW NW

AT °C RT °C DBT °C AT °C RT °C DBT °C

214

40.00

30.00 ᵒC 15.00 ᵒC 20.00

0.00 0.00

winter winter winter winter winter winter winter winter winter winter winter winter

summer summer summer summer summer… summer summer summer summer summer summer summer… summer summer

winter 24On winter winter 24On winter

summer 24On summer 24On summer

winter scheduled… winter scheduled… winter RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC RC SHDsSHDSWC DSF DSFWC GDSFGDSFWC SE NE

AT °C RT °C DBT °C AT °C RT °C DBT °C

Figure (appx 1.3): AT, RT. and DBT of examined cases of natural ventilation

6.00 10.00 4.00 8.00 6.00

MWh 4.00

2.00 MWh 2.00

0.00 0.00

winter… winter winter winter winter winter winter

summer summer summer summer summer… summer summer

winter 24On winter

summer 24On summer summer 24On summer RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC SW NW

6.00 8.00 4.00 6.00

4.00 ac/h 2.00 ac/h 2.00

0.00 0.00

winter… winter winter winter winter winter winter

winter winter winter winter winter… winter winter

summer summer summer summer summer… summer summer

summer summer summer summer summer summer… summer

winter 24On winter

summer 24On summer summer 24On summer RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC SE NE

Figure (appx 1.4): FAF of examined cases of natural ventilation

40 30 30 20

20 kWh 10 kWh 10

0 0

winter winter winter winter winter winter

summer summer summer summer summer summer

winter 24On winter

summer 24On summer

winter scheduled… winter

summer scheduled… summer summer scheduled… summer RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC SW NW

SHGi SHGw SHG SHGi SHGw SHG

215

40 30 30 20

kWh kWh 10 10

0 0

winter winter winter winter winter winter winter winter winter winter winter winter

summer summer summer summer summer summer summer summer summer summer summer summer

winter 24On winter 24On winter

summer 24On summer 24On summer

winter scheduled… winter scheduled… winter

summer scheduled… summer scheduled… summer RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC SE NE

SHGi SHGw SHG SHGi SHGw SHG

Figure (appx 1.5): SHG of examined cases of natural ventilation

5.00 5.00

-5.00 -5.00 kWh kWh -15.00 -15.00 -25.00

-25.00

winter winter winter winter winter winter

summer summer summer summer summer summer

winter 24On winter

summer 24On summer

winter scheduled vent scheduled winter

summer scheduled vent scheduled summer summer scheduled vent scheduled summer RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC SW NW Glazing Walls Ceilings (int) Floors (int) Glazing Walls Ceilings (int) Floors (int) Partitions (int) Internal Natural vent. External Infiltration Partitions (int) Internal Natural vent. External Infiltration

5.00 5.00 -5.00 -5.00

-15.00kWh -15.00kWh -25.00

-25.00

winter winter winter winter winter winter

summer summer summer summer summer summer

winter winter winter winter winter winter

summer summer summer summer summer summer

winter 24On winter

summer 24On summer

winter 24On winter

summer 24On summer

winter scheduled vent scheduled winter

summer scheduled vent scheduled summer

winter scheduled vent scheduled winter summer scheduled vent scheduled summer RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC RC SHDs SHDSWC DSF DSFWC GDSF GDSFWC SE NE Glazing Walls Ceilings (int) Floors (int) Glazing Walls Ceilings (int) Floors (int) Partitions (int) Internal Natural vent. External Infiltration Partitions (int) Internal Natural vent. External Infiltration

Figure (appx 1.6): Heat loss and gain of examined cases of natural ventilation

216

NE MechVent AL NE MXM AL NW MechVent AL NW MXM AL

10.00 10.00 8.00 8.00 6.00 6.00

4.00 4.00

MWH MWH 2.00 2.00

0.00 0.00

RC RC

DSF DSF

SHDs SHDs

GDSF GDSF

DSFWC DSFWC

SHDsWC SHDsWC

GDSFWC GDSFWC

DSFWC.SCH DSFWC.SCH

8 8 6 6 4 4 2 2 0

0 RC

DSF

SHDs

GDSF

DSF

DSFWC

SHDsWC

SHDs

GDSFWC

GDSF

DSFWC

DSFWC.SCH

SHDsWC

GDSFWC DSFWC.SCH

NE MechVent ACL NE MechVent AHL NE MXM ACL NE MXM AHL NW MechVent ACL NW MechVent AHL NW MXM ACL NW MXM AHL

Figure (appx 1.7): HVAC loads of zone NE

Figure (appx 1.8): HVAC loads of zone NW

SE MechVent AL SE MXM AL SW MechVent AL SW MXM AL

10.00 10.00

8.00 8.00

6.00 6.00 MWH MWH 4.00 4.00

2.00 2.00

0.00 0.00 RC SHDsWC DSFWC GDSF RC SHDsWC DSFWC GDSF

8 8 6 6 4 4 2 2 0

0 RC

DSF

SHDs

GDSF

DSF

DSFWC

SHDs

GDSF

SHDsWC

GDSFWC

DSFWC.SC

DSFWC

SHDsWC

GDSFWC DSFWC.SCH

SE MechVent ACL SE MechVent AHL SE MXM ACL SE MXM AHL SW MechVent ACL SW MechVent AHL SW MXM ACL SW MXM AHL

Figure (appx 1.9): HVAC loads of zone SE

Figure (appx 1.10): HVAC loads of zone SW

217

NE NW SE SW NE NW SE SW Glazing Glazing Glazing Glazing Walls Walls Walls Walls 0.00 0.00 -0.50 -1.00 -1.00

-1.50 -2.00 MWh MWh -2.00 -3.00 -2.50 -4.00 -3.00 -3.50 -5.00

RC MECH RC MXM SHDs MECH RC MECH RC MXM SHDs MECH

SHDs MXM SHDsWC MECH SHDsWC MXM SHDs MXM SHDsWC MECH SHDsWC MXM

DSF MECH DSF MXM DSFWC MECH DSF MECH DSF MXM DSFWC MECH

DSFWC MXM DSFWC SCH MECH DSFWC SCH MXM DSFWC MXM DSFWC SCH MECH DSFWC SCH MXM

GDSF MECH GDSF MXM GDSFWC MECH GDSF MECH GDSF MXM GDSFWC MECH

GDSFWC MXM GDSFWC MXM

Figure (appx 1.11): HLg of examined scenarios

Figure (appx 1.12): HLw of examined scenarios RC SHDs SHDsWC DSF DSFWCDSFWC SCHGDSF GDSFWC 0

-20

-40 Figure (appx 1.13): HLif of examined scenarios VENTILATION NE External Infiltration NW External Infiltration SE External Infiltration

GDSFWC RC SHDs SHDsWC DSF DSFWC DSFWC… GDSF 5 3 0 -5 -10 2 -15 -20 -25 1 SW Internal Natural vent.

SE Internal Natural vent. 0 RC

NW Internal Natural vent. DSF

SHDs GDSF

-1 DSFWC SHDsWC

NE Internal Natural vent. GDSFWC DSFWC SCH DSFWC Figure (appx 1.14): Heat loss through NE Partitions (int) NW Partitions (int) internal windows of examined scenarios SE Partitions (int) SW Partitions (int)

Figure (appx 1.15): Heat loss through partitions of examined scenarios

218

400 300 Figure (appx 1.16): FAF of examined 200 scenarios 100 0

DSF

SHDs GDSF

DSFWC 80.00

SHDsWC GDSFWC

60.00 DSFWC SCH DSFWC 40.00 NE FAF NW FAF SE FAF SW FAF 20.00 0.00

Figure (appx 1.17): SHG of examined zones NE MechVent SHG NE MXM SHG NW MechVent SHG NW MXM SHG SE MechVent SHG SE MXM SHG

8000.00 6000.00 4000.00 2000.00 0.00 discomfort discomfort discomfort discomfort discomfort discomfort discomfort discomfort MECH MXM MECH MXM MECH MXM MECH MXM NE NE NW NW SE SE SW SW

RC of C6 SHDs SHDs WC DSF DSF WC DSF WC.SCH DSF&GDSF DSF&GDSF WC

Figure (appx 1.18): According to ASHRAE 55, discomfort hours of examined zones

Table (appx 1.3): Total electricity demands of the building and the amount of generated energy of the examined cases

Heating Room Cooling DHW Lighting Electricity DEF. (Electricity DEF. DEF. generation DEF. Electricity (Electricity) (Electricity) ) kWh kWh kWh kWh kWh kWh BaseLineCase 169793.90 61472.29 524718.60 48851.07 100819.80 143781.50 case 06 169706.00 61440.47 511916.40 2.44 6818.99 86.04 130243.90 22.59 143707.10 0.00 BIPV 169793.90 61472.29 505413.40 3.68 28201.37 42.27 102164.40 1.32 143781.50 267364.30 52.90 BIPV-PV 169793.90 61472.29 503742.80 4.00 30716.99 37.12 97978.02 2.82 143781.50 392786.10 77.97

BIPV-PVA 169793.90 61472.29 498554.60 4.99 32190.06 34.11 91316.79 9.43 143781.50 355326.50 71.27

BIPV+PVP 169793.90 61472.29 498760.00 4.95 35656.09 27.01 88056.20 12.66 143781.50 400521.70 80.30

BIPV-PVGR 169793.90 61472.29 497449.10 5.20 29966.81 38.66 92434.58 8.32 143781.50 355385.70 71.44

219

Table (appx 1.4): Electric loads satisfied of the examined cases

BaselineCase CASE 06 BIPV BIPV-PV BIPV-PVA BIPV-PVP BIPV-PVGR

Percent Percent Percent Percent Percent Percent Percent Electricity Electricity Electricity Electricity Electricity Electricity Electricity Electricity Electricity Electricity Electricity Electricity Electricity Electricity [MWh] [MWh] [MWh] [MWh] [MWh] [MWh] [MWh] [%] [%] [%] [%] [%] [%] [%]

Photovoltaic 0.00 0.00 0.00 0.00 297.07 128.45 423.11 182.95 394.81 170.72 440.14 190.32 394.87 170.74 Power

Power 0.00 0.00 0.00 0.00 -29.71 -12.80 -42.31 -18.30 -39.48 -17.10 -39.62 -17.10 -39.49 -17.10 Conversion

Total On-Site 0.00 0.00 0.00 0.00 267.36 115.61 380.80 164.66 355.33 153.64 400.52 173.19 355.39 153.67 Electric Sources

Electricity Coming From 231.27 100.00 231.15 100.00 130.18 56.29 128.40 55.52 129.16 55.85 128.19 55.43 129.16 55.85 Utility

Surplus Electricity Going 0.00 0.00 0.00 0.00 166.28 71.90 277.93 120.18 253.22 109.49 297.44 128.62 253.28 109.52 To Utility

Net Electricity 231.27 100.00 231.15 100.00 -36.10 -15.60 -149.54 -64.70 -124.06 -53.60 -169.26 -73.20 -124.12 -53.70 From Utility

Total On-Site and Utility 231.27 100.00 231.15 100.00 231.27 100.00 231.27 100.00 231.27 100.00 231.27 100.00 231.27 100.00 Electric Sources

Total Electricity 231.27 100.00 231.15 100.00 231.27 100.00 231.27 100.00 231.27 100.00 231.27 100.00 231.27 100.00 End Uses

Table (appx 1.5): Site energy of QEAB by using RES Site Energy Total Energy [MWh] BIPV- BaselineCase CASE 06 BIPV BIPV-PV BIPV-PVA BIPV-PVP PVGR Total Site 576.48 593.53 561.35 557.74 545.21 542.29 545.33 Energy Net Site 576.48 593.53 293.98 176.94 189.89 141.77 189.95 Energy

220