Phase 2 Report on Environmental Building Regulations & Guidelines

January 2010

Phase 2 Report on Environmental Building Regulations & Guidelines to achieve Energy Efficiency in Bangalore City

Prepared for Renewable Energy & Energy Efficiency Partnership Vienna International Center, Austria

www.teriin.org www.teriuniversity.ac.in

Suggested format for citation

T E R I. 2010 Development of Building Regulations and Guidelines for Energy Efficiency, Bangalore City The Energy and Resources Institute. 154 pp. [Project Report No. 2009BS03]

For more information

T E R I University Tel . 25356590 Centre for Research on Sustainable E-mail [email protected] Building Science Group (CRSBS) Fax 25356589 Southern Regional Centre Web www.teriin.org Bangalore – 560 071 India +91 • Bangalore (0) 80 India

TERI University Project Team

Ms. Minni Mehrotra Ms. Mili Majumdar Mr. Pradeep Kumar Ms. Priyanka Kochhar Dr. Hina Zia Mr. T Senthil Kumar Mr. Nitish Poonia Mr. Kiriti Sahoo

TERI University Project Advisor

Dr. A Ravindra, Advisor to Chief Minister of Karnataka (Urban Affairs) Mr. P R Dasgupta, I A S (Retd), Senior Advisor & Coordinator for TERI South Regional Centre

Secretarial Assistance

Ms. Jyothi

Acknowledgements

We are thankful to the Government of Karnataka officials for their full cooperation and support to carry this project in Bangalore city. We would like to thank:

1. Sri Bharat Lal Meena, I.A.S, Commissioner, Bruhat Bengaluru Mahanagara Palike, Narasimha Raja Square, Bangalore – 560 002 2. Sri Thirukangowdru, Joint Director Town, Bruhat Bengaluru Mahanagara Palike, Narasimha Raja Square, Bangalore – 560 002 3. Sri Siddaiah, I.A.S, Commissioner, Bangalore Development Authority, T. Chowdaiah Road, Kumara Park West, Bangalore – 560 020 4. Sri R. Rangaswamy, Executive Engineer (Electrical) Bangalore Development Authority, T. Chowdaiah Road, Kumara Park West, Bangalore – 560 020 5. Sri T. D. Nanjundappa, Engineer OfficerIII, Bangalore Development Authority, T. Chowdaiah Road, Kumara Park West, Bangalore – 560 020 6. Sri Tushar Girinath, MD, Bangalore Electricity Supply Company Limited, K R Circle Bangalore 560 001 7. Sri B. N. Sathyaprema Kumar, General Manager (HRD), Bangalore Electricity Supply Company Limited, K R Circle Bangalore 560 001 8. Sri Shivananda Murthy H G, MD, Karnataka Renewable Energy Development Ltd., No.19, Maj. Gen. A D Loghanathan, INA Cross, Queen's road., Bangalore 560052. 9. Dr H. Naganagouda, Assistant General Manager, Karnataka Renewable Energy Development Ltd., No.19, Maj. Gen. A D Loghanathan, INA Cross, Queen's road., Bangalore 560052.

List of Contents

INTRODUCTION ...... 1 EXISTING B YE L AWS & R EVISIONS PR OPO SE D ...... 1 FRAME WORK OF ENVIRONMENTAL B UILDING R EGULATIONS AND G UIDELINES FOR B ANGALORE C IT Y ...... 3 GUIDELINE 1: SOLAR PASSIVE D ESIGN FOR NEW B UILDINGS ...... 4 1.1.1 MANDATORY CLAUSE TO BE INCLUDED IN THE REVISED B YE L A W S .. 4 1.2 TECHNICAL N OTES FOR SOLAR PASSIVE DESIGN FOR N EW B UILDINGS .... 4 1.2.1 S OLAR P ASSIVE DE SI GN ...... 4 1.2.2 L ANDSCAPING ...... 5 1.2.3 WATER B ODI ES ...... 5 1.2.4 O RIENTATION ...... 6 1.2.5 B UILDING FORM / SURFACE TO VOLUME RATIO ...... 8 1.2.6 O PTIMIZATION OF BUILDING ENVELOPE ...... 8 1.2.7 W AL L S ...... 9 1.2.8 THERMAL STORAGE / THERMAL CAPACITY ...... 9 1.2.9 C ONDUCTANCE ...... 9 1.2.10 THERMAL INSULATION ...... 10 1.2.11 OPTIMIZATION OF ROOF ...... 10 1.2.12 HEAT GAINS THROUGH ROOFS CAN BE REDUCED BY ADOPTING THE FOLLOWING TECHNIQUES ...... 11 1.2.13 FENESTRATION AND SH A DIN G ...... 15 1.2.14 FINISHES ...... 15 1.2.15 ...... B ENEFITS OF ECBC RECOMMENDED ENVELOPE IN COMPARISON WITH CONVENTIONAL BUILDING ENVELOPE FOR AIR CONDITI ONED BUILDINGS IN B ANGALORE ...... 16 1.2.16 E XTERNAL SHADING OF THE ENVELOPE ...... 17 1.3 L IFE CYCLE C OST ANALYSIS ...... 17 1.4 DAYLIGHT INTEGRATION ...... 18 1.5 B UILDING ENVELOPE OPTIMIZATION FOR NATURALLY VENTILA TED BUILDINGS TO ACHIEVE THERMAL COMFORT ...... 18 1.6 L OW ENERGY P ASSIVE C OOLING S TRATEGIES FOR B ANGAL OR E ...... 21 1.6.1 V ENTILATION ...... 21 1.6.2 RADIATIVE COOLING ...... 24 1.6.3 SOME LOW ENERGY COOLING & DESIGN STRATEGIES THAT COULD BE ADOPTED IN RESIDENTIAL BUILDINGS IN B ANGALORE ARE DESCRIBED B EL OW . T HESE STRATEGIES WERE ANALYSED IN TRNSYS SOFTWARE . ... 25 1.7 EXAMPLE OF A NATURALLY V ENTILATED OFFICE B UILDING IN B ANGAL ORE ...... 25 1.8 S UM M AR Y : ...... 26 1.8.1 N ATURALLY VENTILATED BUILDINGS RECOMMENDATIONS ...... 26 1.9 GL OSSA RY :...... 26 1.10 R EF ERENCE : ...... 27

L IGHTING MANUFACTURER CONTACT DETAILS ...... 27 GUIDELINES 2: P ROVIDE ROOF TREATMENT TO CUT HEAT GAINS ...... 28 2.1 MANDATORY CLAUSE TO BE INCLUDED IN THE REVISED B Y E L A W S ...... 28 2.2 T ECHNICAL G UI DAN CE ...... 28 2.2.1 B RIEF INTRODUCTION ...... 28 2.2.2 H EAT GAINS THROUGH ROOFS CAN BE REDUCED BY ADOPTING THE FOLLOWING TECHNIQUES ...... 30 2.2.3 WHY IS THIS REQUIRED ? ...... 34 2.2.4 HOW IS IT BENEFICIAL ? ...... 34 2.3 GL OSSARY : ...... 36 2.4 REFERENCES : ...... 36 GUIDELINE 3: WINDOW DE SI GN ...... 37 3.1 F OR A IR CONDITIONED BUILDINGS ...... 37 3.2 F OR N ON CONDITIONED BUILDINGS...... 38 3.3.1 WINDOWS IN AI R CONDITIONED BUILDINGS ...... 41 3.3.2 WINDOWS IN N ON C ONDITIONED BUILDING ...... 46 3.3.3 WINDOW D ESIGN FOR NATURAL VENTILATION ...... 50 3.4 GL OSSARY ...... 54 3.5 REFERENCES ...... 54 GU I D ELI N E 4: ENERGY E FFICIENCY IN A RTIFICIAL LI GH TI NG ...... 56 4.1.1 F OR B UILDINGS WITH CONNECTED ELECTRICAL LOAD MORE THAN 100 K W ...... 56 4.1.2 FO R R ESIDENTIAL B UILDINGS ...... 56 4.2.1 C OMMERCIAL & R ESIDENTIAL B UILDINGS ...... 57 4.3.1 EFFICIENCY IN ARTIFICIAL L IGHTING SC H EM E ...... 58 4.3.2 E XTERNAL L I GHTIN G ...... 58 4.3.3 INTERNAL L IGHTING FOR N EW C OMMERCIAL BUILDINGS ...... 61 4.3.4 R ETROFITTING OPTIONS IN E XISTING COMMERCIAL BUILDINGS ....77 4.3.5 INTERNAL L IGHTING FOR N EW R ESIDENTIAL BUILDINGS ...... 77 4.3.6 R ETROFITTING OPTIONS IN E XISTING RESIDENTIAL BUILDINGS ... 80 GUIDELINE 5: ENERGY EFFICIENT A I R CONDITIONING SYSTEM DESIGN FOR BUILDINGS ...... 83 5. 1 G UIDELIN E : ...... 83 5.1.1 MANDATORY CLAUSE TO BE INCLUDED IN THE REVISED B Y E L A W S 83 5. 2 TECHNICAL N O TES ...... 83 5.2.1 AIR CONDITIONING ...... 83 5.2.2 G UIDELINES ON OPTIMIZATION OF COOLING LOAD ESTIMATION ... 84 5.2.3 G UIDELINES ON AHU SPECIFICATIONS TO ACHIEVE ENERGY EFFICIENCY ...... 87 5.2.4 G UIDELINES FOR ENERGY EFFICIENT C HILLERS ...... 90 5.2.5 G UIDELINES FOR ENERGY EFFICIENT C OOLING T O WER ...... 93

GUIDELINE 6: R EPLACE EXISTING EQUIPMENT BY MINIMUM 3 STAR RATED BEE LABELED APPLIANCES EQUIPMENT AND USE MINIMUM 3 STAR RATED BEE LABELED APPLIANCES / EQUIPMENT IN ALL NEW BUILDINGS ...... 94 MANDATORY REQUIREMENT IN ALL PROCUREMENT NORMS FOR G OV ERN M EN T AND PUBLIC BUILDINGS ...... 94 6.1.1 S TAR RATING FOR FROST FREE REFRIGERATOR ...... 96 6.1.2 STAR R ATING R OOM A IR C ONDITIONERS ...... 97 6.1.3 STAR RATING DIRECT C OOL R EFRIGERATOR ...... 97 6.1.4 STAR RATING PL A N : C EILING FA N S ...... 98 6.1.5 STAR R ATING P L AN : ELECTRIC GEYSER S ...... 99 6.1.6 STAR RATING PLAN COLOUR T ELEVISIONS ...... 100 6.1.7 WHY IS THIS REQUIRED ?...... 103 6.1.8 H OW IS IT BENEFICIAL ? ...... 103 GUIDELINE 7: SOLAR WATER HEATING S YSTEMS FOR D OMESTIC AND COMMERCIAL BUILDINGS ...... 105 7.1 MANDATORY REQUIREMENT IN BYELAW ...... 105 7.2.1 G UIDELINES FOR DESIGN , INSTALLATION , AND USE OF SOLAR WATER HEATING SYSTEMS ...... 109 7.2.2 G UIDELINES FOR SYSTEM SELECTION AND USE ...... 110 7.2.3 G UIDELINES FOR INSULATED HOT WATER PIPING ...... 110 7.2.4 H OW IS IT BENEFICIAL ?/W HY IS THIS REQUIRED ? ...... 111 GUIDELINES 8: ENERGY EFFICIENT E LECTRICAL S YSTEMS FOR BUILDINGS 116 8.1 G UIDELINE FOR ENERGY EFFICIENT ELECTRICAL SYSTEMS FOR BUILDING ...... 116 8.1.1 MANDATORY CLAUSE TO BE INCLUDED IN THE R EVISED B YE L AW S 116 8.2 TECHNICAL N OTES FOR E LECTRICAL SYSTEMS ...... 116 8.2.1 G UIDELINES IN E LECTRICAL SYSTEM DESIGN ...... 116 8.2.2 G UIDELINES ON OPTIMIZATION OF ELECTRICAL LOAD ...... 117 8.2.3 G UIDELINES ON T RANSFORMER R ATING AND SELE CT I ON ...... 119 8.2.4 G UIDELINES ON SELECTION OF E LECTRICAL M OTOR S ...... 120 8.2.5 G UIDELINES ON IMPROVEMENT OF P OWER FACTOR ...... 122 8.2.6. G UIDELINES ON C HECK M ETERING AND MONITORING ...... 125 8.2.7 G UIDELINES ON DISTRIBUTION SYSTEM LOSSES ...... 126 8.2.8 G UIDELINES ON P OWER BACK UP SYSTEMS ...... 129 8.2.9 G UIDELINES ON P OWER Q UAL ITY ...... 131 GUIDELINE 9: P ERFORM MANDATORY ENERGY AUDIT FOR EXISTING COMMERCIAL BUILDINGS WITH CONNECTED LOAD OF CASES OF 500 KW OR 600 KVA AND APPLY ENERGY CONSERVATION MEASURES TO REDUCE ENERGY CONSUM PTION IN EXISTING COMMERCIAL /INSTITUTIONAL BUILDINGS ...... 133 9.1 G UIDELIN E : ...... 133 9.1.1 MANDATORY REQUIREMENT ...... 133

9.2 G UIDANCE NO TE S ...... 133 9.3 ENERGY DEMAND AND C ONSUMPTION ...... 134 9.4 AUDIT OF INDIVIDUAL SYSTEMS ...... 137 9.4.1 ELECTRICAL SYSTEM ...... 137 9.4.2 L IGHTING SY ST EM ...... 139 9.4.3 HVAC SYS TEM ...... 144 9.5 C ONTROLS IN THE HVAC SYSTEM RECOMMENDED BY ENERGY CONSERVATION B UILDING C ODE (ECBC) ...... 152 9.6 B ENEFITS ...... 153 9.7 GL OSSARY ...... 153

INTRODUCTION

In phase II of the project framing of environmental building regulations and guidelines to achieve energy efficiency and integrate renewable energy in Bangalore city is completed. It is proposed that the recommended regulations shall become a part of the existing building bye laws of Bangalore city and a separate document on guidelines will be published. This separate guidelines document will be available along with the building bye laws of Bangalore for the citizens of Bangalore city.

The study in the phase II was divided into two parts. 1. Study of existing building bye laws of Bangalore and identify sections which could be improved or detailed out for achieving energy efficiency in Buildings in Bangalore city. 2. A set of guidelines and regulations are proposed to achieve energy efficiency and integrate renewable energy in the city.

Existing Bye Laws & Revisions Proposed

Under General Building Requirements following sections have been identified which need revision or detailing.

Section 3.1.6 & 3.1.7, Width of road & Means of access According to the regulation, F.A.R and height of the building shall be regulated according to the width of public street or road. This is important to integrate daylight and natural ventilation inside the buildings. Revisions Proposed This section has been detailed out. Relation between Height of building & separation between two buildings has been established with respect to WWR (Window Wall Ratio) and Light transmittance of glass required for various Height / Separation ratio. This is included in optimization of window design guideline.

Section 3.2 3 Basements According to the existing bye law, when basement is used for car parking, the convenient entry and exit shall be provided. Adequate drainage, ventilation, lighting arrangements and protection against fire shall be made to the satisfaction of the authority. Revisions proposed The daylight and natural ventilation requirement for basements will be specified in detail in the existing bye laws.

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Section 3.3 Requirements of Building Services 3.3.1 Lighting and ventilation requirements

Natural ventilation and area of opening According to the existing bye laws, rooms shall have, for admission of light and air, one or more openings. Minimum aggregate area of openings excluding doors, shall not be less than 1/6 th of the floor area in case of residential buildings. In case of other public buildings like institutes, offices, hospitals etc minimum aggregate area of opening shall be not less than 1/5 th of the floor area. Proposed guideline There is a separate guideline framed on optimization of window design for air conditioned and non air conditioned buildings.

Section 3.3.3 Transformer According to the existing bye laws, where the specified load is 25kW or more a space for locating the distribution transformers and associated equipment as per KERC code leaving 3.0m from the building and without obstructing the fire driveway within the premises has to be provided. Revisions proposed A separate guideline along with some mandatory clause has been framed for installation and design of energy efficient electrical system in buildings. This includes a mandatory requirement of Transformers to comply with Energy Conservation Building Code (ECBC) of India requirements.

Section 3.3.5 Electrical installations, Air conditioning and heating According to the existing bye laws, the planning, design and installation of air conditioning and heating installations of the building shall be in accordance with Part VIII of the National Building Code of India. Revisions proposed A separate guideline along with some mandatory clause has been framed for design of energy efficient air conditioning system for buildings in Bangalore.

Section 3.4.10 Solar energy According to the existing bye laws, • Solar lighting and solar water heating is mandatory for all new development/construction for different categories of buildings. If solar lighting and solar water heating is adopted, then refundable security deposit on fulfilling the conditions shall be returned with 2% interest. • Solar photovoltaic lighting systems shall be installed in multi unit residential buildings (with more than five units) for lighting the set back areas and drive ways.

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Revisions proposed • In the existing bye law, the requirements for different building types are not clear; this has been proposed in a separate guideline. Further incentives will be framed for all mandatory regulations in phase 3 of this project. • For external solar lighting integration, separate guideline and mandatory clause has been framed.

Frame work of Environmental Building Regulations and Guidelines for Bangalore City Part II of this report below comprises of the environmental building guidelines and mandatory regulations framed for Bangalore city to achieve energy efficiency and integrate renewable energy. Briefly 9 sections of guidelines & regulations have been framed, which are described below and further detailed out later.

1. Solar passive design integration in new buildings.

2. Provide roof treatment to cut heat gains.

3. Window design for day lighting, ventilation and to reduce solar heat gains.

4. Artificial lighting a. Energy efficient external lighting b. Renewable energy based external lighting c. Efficient indoor lighting for new commercial buildings, follow ECBC prescriptive / mandatory criteria for lighting design d. Efficient indoor lighting for new residential buildings e. Retrofit options for existing commercial buildings f. Retrofit options for existing residential buildings

5. Energy efficient air conditioning design for buildings.

6. Use of BEE labeled equipments and appliances to achieve energy efficiency in new and existing buildings.

7. Solar water heating systems for residential and commercial buildings.

8. Energy efficient electrical systems for building

9. Perform mandatory energy audit for existing commercial buildings with connected load in cases of 500kW or 600KVA and reduce energy consumption by 20% over previous year.

GUIDELINE 1: Solar Passive Design for New Buildings

1.1 Guideline for Solar Passive design for New Buildings

Achieve thermal and visual comfort inside the building by using natural energy sources and sinks, such that there is significant reduction in energy consumption by conventional air conditioning and artificial lighting in a building.

1.1.1 Mandatory clause to be included in the Revised Bye Laws

Design external shading for windows to protect heat gains from direct solar radiation and for protection against rain. In air conditioned buildings windows should comply with ECBC requirement. Roof should either comply with ECBC requirements or should be shaded.

Table 1.1 : Roof assembly Ufactor requirements as per ECBC 2007 Climate zone 24Hour use buildings Daytime use buildings Hospitals, Hotels, Call centers etc. Other building Types Maximum Ufactor of the overall assembly (W/m2K) Maximum Ufactor of the overall assembly (W/m2K) Moderate U0.409 U409

Vertical Fenestration Ufactor and SHGC Requirements (Ufactor in W/m2K) Maximum Ufactor (W/m 2 Maximum SHGC for Maximum SHGC for Climate K) WWR ≤ 40% 40%

1.2 Technical Notes for Solar Passive design for New Buildings

Technical guidance to achieve the recommendations

1.2.1 Solar Passive Design Solar passive buildings are designed to achieve thermal and visual comfort by using natural energy sources and sinks eg, solar radiation, outside air, wet surfaces, vegetation etc. The solar passive design strategy should vary from one climate to another. For example in Bangalore which falls in Moderate climate zone, natural ventilation could be very effective, however in Hyderabad which falls under Hot & dry climate zone, evaporative cooling could be very effective. Architects can achieve a solar passive design by studying the macro and micro climate of the site, applying bioclimatic 5 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City architecture design features and taking advantage of existing natural resources on the site. Designers can achieve energy efficiency in the buildings they design by studying the macro and micro climate of the site, applying solar passive and bio climatic design features and take advantage of natural resources on site.

Designers can achieve solar passive building design by following the below mentioned steps.

1. Modulating the microclimate of the site through landscaping 2. Optimization of orientation and building form 3. Optimization of building envelope and window design to reduce cooling demand 4. Daylight integration to reduce artificial lighting demand. 5. Low energy passive cooling strategies

1.2.2 Landscaping Landscaping by vegetation is one of the most effective ways of altering micro climate for better conditions. Trees provide buffer to sun, heat, noise, air pollution. Landscaping can be used to direct or divert the air flow advantageously. Trees help to shade the building from intense direct solar radiation. Tree species could be selected depending upon climate zone and building design. Deciduous trees for example, provide shade in the summer and sunlight in the winter when their leaves fall. Planting Figure 1.1: Water and trees as landscape them on West and South West orientation of a building elements at Sangath, Ahmedabad provides natural shade. Evergreen trees provide shade and wind control round the year. Natural cooling without air conditioning can be achieved by locating trees to channel cool breeze inside the buildings. Additionally, the shade created by trees, reduces air temperature of the micro climate around the building through evapo transpiration. Properly designed roof gardens help to reduce heat loads in a building.

1.2.3 Water Bodies Water has a moderating effect on the air temperature of the micro climate. It possess very high thermal storage capacity much higher than the building materials like Brick, concrete, stone. A large body of water in the form of lake, river, fountain has the ability to moderate the air temperatures in the micro climate. Water evaporation has a cooling effect in the surroundings. It takes up heat from the air through evaporation and causes significant cooling.

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1.2.4 Orientation In solar passive buildings, orientation is a major design consideration, mainly with regard to solar radiation, daylight and wind. The orientation of the building should be based on whether cooling or heating is predominant requirement in the building. The amount of solar radiation falling on a surface varies with orientation. In tropical climate zones for example, North Orientation receives solar radiation with minimum intensity as seen in figure 2. Thus in tropical climate like India long facades of buildings oriented towards North— South are preferred. South orientation receives maximum solar radiation during winters which is preferable. East and West receive maximum solar radiation during summer. West is a crucial orientation because high intensity of solar radiation is received during evening hours, when the internal gains are also at its peak. Thus, designers need to be very careful while designing West façade and spaces behind west façade. Orientation also plays an important role with respect to wind direction. At building level, orientation affects the heat gain through building envelope and thus the cooling demand, orientation may affect the daylight factor depending upon the surrounding built forms, and finally the depending upon the windward and leeward orientation fenestration could be designed to integrate natural ventilation

Figure 1.2: Average daily solar radiation received on North orientation facade

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Figure 1.3: Average daily solar radiation received on South orientation facade

Figure 1.4: Average daily solar radiation received on East orientation facade

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Figure 1.5: Average daily radiation received on West orientation facade

1.2.5 Building form / surface to volume ratio Thermal performance of volume of a space inside the building has direct relationship with the area of the envelope enclosing that volume. This parameter known as the S/V (Surface / volume) ratio, is determined by the building form. Building form affects solar access and wind exposure as well as the rate of heat gain and heat loss through the external envelope. A compact building gains less heat during the daytime and losses less heat at night. In Bangalore, buildings that are compact and have low S/V ratio to reduce heat gains are preferred. Four building geometries were studied for Bangalore climate zone to analyse the most efficient form which gains minimum heat gain from the external surfaces. These were square, rectangular, courtyard and circular.

In Moderate climate zone of Bangalore, the Energy Performance Index (EPI) of circular building is lowest, in comparison to other building forms. This is because circular building has the lowest Surface to Volume ratio. It is observed in VisualDOE software results that due to circular geometry, the conduction gains from the building envelope as well as solar gains from windows are least, in circular geometry in comparison to other building geometries. The building form also determines the air flow around the building and hence the ventilation rates inside. Circular form of building is an aerodynamic form which would also help enhance natural ventilation inside the building. The depth of the building determines the amount of daylight which can penetrate inside the building. Deeper the building, more artificial lights required which is not preferred in an energy efficient building.

1.2.6 Optimization of building envelope 9 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Choice of building material for the envelope is important to reduce the energy consumption of the building, through reduced solar heat gain or loss thus reducing air conditioning loads. Optimized selection of building material for external envelope also plays an important role in achieving thermal comfort in buildings where thermal comfort is achieved through passive cooling strategies such as natural ventilation.

Building envelope Building envelope components are the key determinants of the amount of heat gain or loss and wind that enters inside the building. The important components of building envelope which affect the performance of the building are:

• Walls • Roof • Windows • Surface finishes

1.2.7 Walls Walls are a major part of the building envelope, which are exposed to external environment conditions (solar radiation, outside air temperature, wind, precipitation). The composition of wall and thereby its heat storing capacity and heat conduction property has a major impact on indoor thermal comfort in naturally ventilated buildings and on cooling loads in air conditioned buildings. The wall material, thickness, finishes should be selected according to climate zone and building’s comfort requirement.

1.2.8 Thermal storage / thermal capacity Thermal capacity is the measure of the amount of energy required to raise the temperature of a layer of material, it is a product of density multiplied by specific heat and volume of the construction layer. The main effect of heat storage within the building structure is to moderate fluctuation in the indoor temperature.

In a building system, we can understand thermal mass as the ability of a building material to store heat energy to balance the fluctuations in the heat energy requirements or room temperature in the building due to varying outside air temperature. The capacity to store heat depends upon the mass and therefore on the density of the material as well as on its specific heat capacity. Thus, high density materials such as concrete, bricks, stone are said to have high thermal mass owing to their high capacity to store heat while lightweight materials such as wood, or plastics have low thermal mass. The heat storing capacity of building materials help achieve thermal comfort conditions by providing a time delay. This thermal storage effect increases with increasing compactness, density and specific heat capacity of materials.

1.2.9 Conductance Conductivity (K) is defined as the rate of heat flow through a unit area of unit thickness of the material, by a unit temperature difference between the two sides. The unit is W/mK (Watt per metre degree Kelvin). The conductivity value varies from 0.03 W/mK for 10 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City insulators to 400W/mK for metals. Materials with lower conductivity are preferred, as they are better insulators and would reduce the external heat gains from the envelope.

1.2.10 Thermal insulation Thermal insulation plays an important role in reducing the conductance or U value (W/m2K) of walls and roof. Insulation should always be placed on the hotter side of the surface. Thermal mass is not a substitute of insulation; in fact a high thermal mass material is usually not a good thermal insulator. Buildings should use insulation in combination with heat storing material. This storing mass should be placed towards the inside in passively cooled buildings.

Energy Conservation Building Code (ECBC) requirement for external walls For air conditioned buildings, ECBC recommends thermal performance for external opaque walls. These are mentioned below:

Climate zone 24Hour use buildings Daytime use buildings Hospitals, Hotels, Call centres etc. Other building Types Maximum Ufactor of the overall assembly (W/m2K) Maximum Ufactor of the overall assembly (W/m2K) Moderate U0.440 U440

1.2.11 Optimization of roof Fig 1.6, shows the intensity of solar irradiation is maximum on the horizontal plane which is the roof. Conductance of heat from the roof can be very high if not insulated well. This can result in increased cooling load if the space below is air conditioned or high discomfort hours if the space below is naturally ventilated.

Figure 1.6: Average daily Intensity of solar radiation incident on horizontal roof surface in Bangalore

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1.2.12 Heat gains through roofs can be reduced by adopting the following techniques.

Green roof concept Green roofs have the potential to improve the thermal performance of a roofing system through shading, insulation, evapo transpiration and thermal mass, thus reducing a building’s energy demands for space conditioning. The green roof moderates the heat flow through the roofing system and helps in reducing the temperature fluctuations due to changing outside environment. Figure 1.7: Roof of buildings with roof garden

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Green roof is a roof of a building that is partially or completely covered with vegetation and soil that is planted over waterproofing membrane. If widely used green roofs can also reduce the problem of urban heat island which would further reduce the energy consumption in urban areas.

Use of high reflective material on roof top Use light coloured roofs having an SRI (solar reflectance Figure 1.8: Broken china mosaic can be used as an index) of 50% or more. The dark coloured, traditional external roof finish to reflect the incident solar radiation roofing finishes have SRI varying from 5 20%. A good example of high SRI is the use of broken china mosaic and light coloured tiles as roof finish, which reflects heat off the surface because of high solar reflectivity and infrared emittance, which prevents heat gain and thus help in reducing the cooling load from the building envelope.

Thermal insulation for roof Well insulated roof with the insulation placed on the external side is an effective measure to reduce solar heat gains from the roof top. The insulated materials should be well protected by water proofing.

For air conditioned spaces, Energy Conservation Building Code (ECBC) recommends the thermal performance for external roof for all the five climate zones in India. Bangalore falls under Moderate climate zone, the maximum Uvalue recommended by ECBC for moderate climate zone is mentioned below:

Table 1.2: Roof assembly Ufactor requirements as per ECBC 2007 Climate zone 24Hour use buildings Daytime use buildings Hospitals, Hotels, Call centers etc. Other building Types Maximum Ufactor of the overall assembly (W/m2K) Maximum Ufactor of the overall assembly (W/m2K) Moderate U0.409 U409

Examples of ECBC compliant roof assembly Roof Ufactor (SI) Ufactor Btu/h (sfoF) Rs/sf Foam concrete or perlite instead of mud Phuska 0.069 0.012 130 RCC slab with Extruded polystyrene 2.4” – 36 kg/m3 0.380 0.067 252 RCC slab with Extruded polystyrene 3” – 36 kg/m3 0.312 0.055 278 RCC slab with Expanded polystyrene (thermocole) 3” – 24 kg/m3 0.409 0.072 205 RCC slab with Phenolic foam 2.4” – 32 kg/m3 0.363 0.064 270 RCC slab with Phenolic foam 3” – 32 kg/m3 0.301 0.053 302 RCC slab withPolyurethane spray 2.4” – 42 ± 2 kg/m3 0.319 0.056 229 RCC slab withPolyurethane spray 3” – 42 ± 2 kg/m3 0.259 0.046 246 RCC slab withPolyisocyanurate spray 2.4” – 42 ± kg/m3 0.329 0.058 233 RCC slab withPolyisocyanurate spray 3” – 42 ± kg/m3 0.267 0.047 251

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Insulation + cool roof Along with lower Uvalue for roof, ECBC also recommends cool roof. Cool roofs are roofs covered with a reflective coating that has high emissivity property which is very effective in reflecting the sun’s energy away from the roof surface. These cool roofs are known to stay 10deg to 16dg C cooler than normal roof under a hot summer day. This quality greatly helps in reducing the cooling load that needs to be met by the HVAC system. Combination of insulated roof along with cool roof has higher saving energy potential.

External shading of roof Shading of roof through design features like pergola or solar photovoltaic panels help reduce the incident direct solar radiation on the roof surface. This in turn helps to reduce the sol air temperature of the roof and conduction gains in the space below. It is observed using software simulations that shading of roof has equal potential in reducing the energy consumption by air conditioning as that of an insulated roof.

Thermal properties of few building and insulating materials for reference are given below in table 1.3.

Table 1.3: Thermal Properties of Building and Insulating Materials at Mean Temperature of 50deg.C SL. TYPE OF MATERIAL DENSITY THERMAL SPECIFIC HEAT NO. CONDUCTIVITY* CAPACITY (1) (2) (3) (4) (5)

Kg / m3 W / (m.K) KJ / (kg.K)

Building Materials

1. Burnt brick 1 820 0.811 0.88

2. Mud brick 1 731 0.750 0.88

3. Dense concrete 2 410 1.74 0.88

4. R.C.C. 2 288 1.58 0.88

5. Limestone 2 420 1.80 0.84

6. State 2 750 1.72 0.84

7. Reinforced brick 1 920 1.10 0.84

8. Brick tile 1 892 0.798 0.88

9. Line concrete 1 646 0.730 0.88

10. Mud Phuska 1 622 0.519 0.88

11. Cement mortar 1 648 0.719 0.92 14 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

12. Cement concrete 1 762 0.721 0.84

13. Cinder concrete 1 406 0.686 0.84

14. Foam slag concrete 1 320 0.285 0.88

15. Gypsum plaster 1 120 0.512 0.96

16. Cellular concrete 740 0.188 1.05

17. AC sheet 1 520 0.245 0.84

18. GI sheet 7 520 61.06 0.50

19. Timber 480 0.072 1.68

20. Timber 720 0.144 1.68

21. Plywood 640 0.174 1.76

22. Glass 2 350 0.814 0.88

23. Alluvial clay (40 percent sans) 1 958 1.211 0.84

24. Sand 2 240 1.74 0.84

25. Black cotton clay (Madras) 1 899 0.735 0.88

26. Black cotton clay (Indore) 1 683 0.606 0.88

27. Tar felt (2.3 kg/m3) 0.479 0.88 (Source, Handbook on Functional Requirements of buildings, SP:41—1987, BIS)

SL. TYPE OF MATERIAL DENSITY THERMAL SPECIFIC HEAT CAPACITY NO. CONDUCTIVITY* (1) (2) (3) (4) (5) Kg / m3 W / (m.K) KJ / (kg.K) Insulating Materials 1. Expanded polystyrene 16.0 0.038 1.34 2. Expanded polystyrene 24.0 0.035 1.34 3. Expanded polystyrene 34.0 0.035 1.34 4. Foam glass 127.0 0.056 0.75 5. Foam glass 160.0 0.055 0.75 6. Foam concrete 320.0 0.070 0.92 7. Foam concrete 400.0 0.084 0.92 8. Foam concrete 704.0 0.149 0.92 9. Cork slab 164.0 0.043 0.96 10. Cork slab 192.0 0.044 0.96 11. Cork slab 304.0 0.055 0.96 12. Rock wool (unbonded) 92.0 0.047 0.84 13. Rock wool (unbonded) 150.0 0.043 0.84 14. Mineral wool (unbonded) 73.5 0.030 0.92 15. Glass wool (unbonded) 69.0 0.043 0.92 16. Glass wool (unbonded) 189.0 0.040 0.92 15 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

17. Resin bonded mineral wool 48.0 0.042 1.00 18. Resin bonded mineral wool 64.0 0.038 1.00 19. Resin bonded mineral wool 99.0 0.036 1.00 20. Resin bonded glass wool 16.0 0.040 1.00 21. Resin bonded glass wool 24.0 0.036 1.00 22. Exfoliated vermiculite (loose) 264.0 0.069 1.00 23. Asbestos mill board 1 397.0 0.249 0.88 24. Hard board 979.0 0.279 0.84 25. Straw board 310.0 0.057 1.42 26. Soft board 320.0 0.066 1.30 27. Soft board 249.0 0.047 1.30 28. Wall board 262.0 0.047 1.30 29. Chip board 432.0 0.067 1.26 30. Chip board (perforated) 352.0 0.066 1.26 31. Particle board 750.0 0.098 1.30 32. Coconut pith insulation board 520.0 0.060 1.09 33. Jute fibre 329.0 0.067 1.09 34. Wood wool board 398.0 0.081 1.13 (bonded with cement) 35. Wood wool board 674.0 0.108 1.13 (bonded with cement) 36. Coil board 97.0 0.038 1.00 37. Saw dust 188.0 0.051 1.00 38. Rice husk 120.0 0.051 1.00 39. Jute felt 291.0 0.042 0.88 40. Asbestos fibre (loose) 640.0 0.060 0.84

1.2.13 Fenestration and Shading Of all the elements of building envelope, windows and glazed areas are most vulnerable to heat gains. Windows are required to bring inside natural daylight and wind, however, with light it also brings in heat. Proper location, sizing and detailing of windows and shading form is therefore a very important aspect in a solar passive building design. Hence window design has been detailed out as separate guidelines, which should be referred separately.

1.2.14 Finishes The external finish of a surface determines the amount of heat absorbed or rejected by it. For example, a smooth and light coloured surface reflects more light and heat in comparison to a dark surface. Light colours have higher emissivity and hence should be preferred in Moderate climate zones like Bangalore where the intensity of solar radiation is very high. Emissivity is the measure of the capacity of a surface to emit radiation. 16 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

The internal surfaces should also be finished in light colours, as that helps in obtaining higher reflectance of light inside the space

1.2.15 Benefits of ECBC recommended envelope in comparison with conventional building envelope for air conditioned buildings in Bangalore

It is observed in air conditioned buildings, adopting ECBC envelope in building has high energy saving potential. Energy simulation engine was used to quantify energy saving potential in a daytime office building. It is observed that use of ECBC envelope results in annual electricity saving up to 12% in comparison with conventional envelope. In this analysis following was the ECBC and conventional envelope.

Walls Composition (External to internal) U value (W/m2K) ECBC case Stone cladding+75mm Expanded Polystyrene+230mm Brick wall + internal 0.39 plaster Conventional case External plaster +230mm brick wall + internal plaster 1.87

Roof Composition (External to internal) U value (W/m2K) ECBC case Roof finish+75mm Expanded Polystyrene+150mm Concrete slab + internal 0.39 plaster Conventional case Roof finish +150mm concrete slab + internal plaster 1.81

Glass

ECBC case (Double glazed unit) U value: 1.31 W/m2K SHGC = 0.27 VLT = 40% Conventional case (Single glazed unit) Uvalue =6.16 W/m2K SHGC = 0.81 VLT = 0.88

LCC of conventional and ecbc envelope for air conditioned commercial buildings

90000000

80000000

70000000

60000000

50000000 Conventional envelope R s 40000000 ECBC envelope

30000000

20000000

10000000

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Year 17 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

1.2.16 External shading of the envelope It is observed that latitude , longitude of Bangalore recieves high intensity of solar radiation. Though the air temperature is cool, making Bangalore fall under Moderate climate zone, the solar radition intensity is very high. Thus one of the effective solar passive design measure for Bangalore city is external shading of walls, roof, windows to reduce the external heat gains. Simulation engine was used to quantify the saving potential in an air conditioned building in Bangalore due to external shading. It is noted that energy saving upto 15% is possible through shading of roof by using elements like pergola, shading of East and west wall and through shading of windows.

1.3 Life Cycle Cost Analysis There can be three cases considered for optimized building envelope to provide maximum energy saving potential due to optimum selection of building envelope.

These are: 1. Compliance of building envelope with ECBC (Energy Conservation Building Code) recommendations. 2. Shading of envelope to reduce to reduce solar heat gains. This includes shading of East and West orientation facades, shading of roof and shading of windows. 3. Shading of East & West walls, shading of roof and ECBC compliant window.

Case % Energy saving % Increment in initial % Saving in Life Pay back period potential cost Cycle Cost (LCC) Base case ECBC envelope 13%% 1.3% 1% 8 years Shaded envelope 16% 1.2% 1.9% 5 years Shaded walls, roof and 16% 1.3% 1.9% 5 years ECBC window

Thus it is recommended from the above analysis that : • Windows in air conditioned spaces should comply with ECBC recommendation. • Windows in naturaly ventilated spaces should be fully shaded. • Roof should be either compliant with ECBC recommendations or should be shaded. • East and West walls should be shaded.

18 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Life Cycle Cost Analysis for building envelope options

120

110

100

40 Rupees(Million) 30

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Years

Base case ECBC envelope case Proposed Shading envelope case Proposed shadingw all,roof+ecbc glass

1.4 Daylight Integration Daylight is a natural source of light, which meets all the requirements of good lighting. Daylight provides a dynamic environment inside the building in consonance with the nature outdoors. Windows in buildings establish contact with nature through direct view and admit daylight inside. Adequate provision of daylight in buildings through proper planning of windows, in respect of position, area and shape is therefore an important aspect of a good building design. Daylight integration helps reduce dependence on artificial lighting and thus reduction in electricity consumption of the building. Details on daylight integartion is part of the window guideline.

1.5 Building envelope optimization for naturally ventilated buildings to achieve thermal comfort Optimizing envelop requirement is one of the most important strategies to lower down heat built up in the interior space , hence plays a vital role in achieving thermal comfort as prescribed in the National Building Code 2005 for Naturally ventilated buildings.

Optimize building envelope to reduce heat gains and maximize thermal comfort in naturally ventilated building.

Buildings occupied for 24 hours Residences For the achievement of thermal comfort in the naturally ventilated spaces of residences, following guidelines should be followed: 1. For the effectiveness of natural ventilation, window should be designed as per the guideline outlines in “window design for Natural ventilation”. 2. Windows should be fully shaded in order to maximize thermal comfort in the space. 19 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

3. Building envelope should be as per the recommendations included in this guideline. This recommended envelope design is for naturally ventilated residential spaces with 6 air change per hour.

Buildings occupied for Day time hours (9 hours) Offices For the achievement of thermal comfort in the naturally ventilated office spaces, following guidelines should be followed: For the effectiveness of natural ventilation, window should be designed as per the guideline outlined in “Window Design for Natural Ventilation”. Windows should be fully shaded in order to maximize thermal comfort in the space. Building envelope should be as per the recommendations included in this guideline. Building envelope should be as per the recommendations included in this guideline. This recommended envelope design is for naturally ventilated office spaces with 6 air change per hour. Optimum Building Envelop Configuration for Naturally Ventilated Residences and Offices:

The recommended envelop of the space shall be as per the following properties:

Table 1.4: Envelop Specifications Envelope with brick wall Composition Uvalue Wall Plaster + brick + plaster 2.203 Roof (Insulated) Plaster + concrete + expanded polystyrene + plaster + stone 0.349 Floor Floor + stone + concrete 0.417 Glass for opening Single glazing unit fully shaded

Envelope with concrete wall Composition Uvalue Wall Plaster + concrete + plaster 3.443 Roof (Insulated) Plaster + concrete + expanded polystyrene + plaster + stone 0.349 Floor Floor + stone + concrete 0.417 Glass for opening Single glazing unit fully shaded

Envelope with mudblock Composition Uvalue wall Wall Plaster + mud block + plaster 3.443 Roof (insulated) Plaster + concrete + expanded polystyrene + plaster + stone 0.349 Floor Floor + stone + concrete 0.417 Glass for opening Single glazing unit (fully shaded)

1. The UValue prescribed in the table should be taken as recommendation while designing the roof, wall, and floor component. 2. For the clarity of the user it should be noted that, the different combinations of envelop differs from each other with respect to only wall material; while the roof , floor and glazing type remains the same.

20 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Figure 1.9: Zone Temperature conditions of non air conditioned space in office and residences on hottest day (April 11) of the year

21 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

1.6 Low energy Passive Cooling Strategies for Bangalore

Bangalore falls under moderate climate zone with favorable outdoor conditions to design hybrid low energy buildings. Weather analysis for Bangalore shows that design strategies such as shading from direct solar radiation and natural ventilation are very effective in achieving comfort in non air conditioned living spaces. High thermal mass and evaporative cooling are other effective design strategies shown in figure below reference: Climate calculator)

1.6.1 Ventilation Ventilation fulfills a number of requirements associated with human comfort: Health: respiration, odour avoidance and pollutant removal. Cooling: removal of heat produced by internal and solar gains, both during daytime and at night time. Comfort: Provision of air movement to increase perceived cooling.

Methods of ventilation Ventilation requirement could be met by the following ways: 1. Natural ventilation 2. Mechanical ventilation 3. Mixed mode ventilation 22 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Natural Ventilation Natural ventilation systems rely on pressure to move fresh air through buildings. Pressure difference can be caused by wind (cross ventilation) or the buoyancy effect created by temperature differences or differences in humidity (stack effect). In both the cases the amount of ventilation critically depends on design of openings, their size and placement. Natural ventilation unlike forced ventilation uses natural sources like wind and buoyancy to deliver fresh air into the building.

Cross Ventilation A pressure is generated on a surface whenever moving air is obstructed or deflected. The distribution of pressure depends upon the wind direction and the geometry of the surfaces. Pressures will generally be positive on the windward sides of buildings and negative on leeward sides. The lateral pressure distribution gives rise to crossventilation; that is airflow from the windward Figure 1.10: Cross ventilation achieved through to the leeward side of the building. This requires that the openings interior of the building is not sealed by dividing walls, or that where rooms are double banked, openings at high level are provided. Cross ventilation was assisted by having high level openings in the internal walls and over doors in traditional houses.

Stack Effect Air moves through a structure in response to pressure differences generated by either the thermal buoyancy (stack effect) or wind. Buoyancy pressures are generated by air warmer than its surroundings as the warmer air is of lower density than the cooler air. Figure 11: Stack effect through openings at different level. The pressure generated is dependent upon the average temperature difference between inside and outside and the height of the 'stack' or column of warmer air. Where there are openings at the top and bottom of the stack, the cooler heavier air will enter the lower openings and displace the warmer lighter air at the top. This is known as 'displacement ventilation', and if there is a source of heat which maintains the stack, the flow will continue. It is important to note that in these conditions air temperatures low down will be close to outdoor temperatures and those higher up will be warmer.

23 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Traditionally, this concept was used very commonly by having high ceilings in conjunction with ventilators and low level openings, courtyards and atria.

Probable indoor wind speed The available wind speed in a room with single window on the windward side is about 10 percent of outdoor velocity. The value however is increased upto 15 percent when two windows are provided instead of one and wind impinges obliquely on them. Effect of area of openings on the indoor wind velocity is depicted in the graph below. Building design guidelines for natural ventilation

1. Maximize wind induced ventilation by orienting the longer facades of the building towards predominant wind direction. However, if this is not possible, it could be oriented at any convenient angle between 0o and 30o without loosing any beneficial aspect of the breeze.

2. Inlet openings in the buildings should be well distributed and should be located on the windward side at a low level, and outlet openings should be located on the leeward side at a higher level, to maximize the stack effect. Nocturnal cooling 3. Buildings should be sited where obstructions for summer winds are minimum.

4. Naturally ventilated buildings should have a narrow floor width, infact its difficult to naturally ventilate buildings with floor depth more than 45feet.

5. For total area of openings (inlet and outlet) of 20 to 30% of floor area, the average indoor wind velocity that could be achieved is around 30% of outdoor wind velocity. Even on increasing the size of window further, the maximum indoor wind velocity does not exceed 40% of outside wind velocity.

6. Window openings should be operable by occupants. Direct evaporative cooling, source Passive cooling techniques, B. Mohanty

7. In addition to the primary consideration of airflow in and out of the building, airflow between the rooms of the building is important. Where possible, interior doors should be designed to be open to encourage wholebuilding ventilation.

8. Use of clerestories or vented skylights, A clerestory or a vented skylight will provide an opening for stale air to escape in a buoyancy ventilation strategy. The light well of the skylight could also act as a solar chimney to augment the flow. Openings lower in the structure, such as basement windows, must be provided to complete the ventilation system.

Evaporative Cooling Evaporative cooling lowers indoor air temperature by evaporative cooling. This cooling strategy is also effective in Moderate climate of Bangalore. In evaporative cooling the 24 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City sensible heat of air is used to evaporate the water, thereby releasing energy and air gets cooled, which in turn cools the indoor living spaces. Increase in contact between air and water increases the rate of evaporation. Water bodies like ponds, lake or fountains in the landscape help reduce micro climate air temperature around the buildings.

Traditionally also evaporative cooling has been used to cool the hot breeze. Water was used commonly to reduce local temperatures by evaporative cooling, to humidify the air and also to clean the air by capturing dust particles. It has been calculated that the temperature of 1 cubic metre of air will be reduced by 1 °C by the evaporation of 05 g of water (Evans). In public buildings water in pools and fountains can be used as a cooling element combined with a crossventilating arrangement of openings.

Figure 13: Ways of integrating evaporative cooling Figure 12: HUL solar passive building in Bangalore with ponds integrated in the circulation areas to integrate evaporative cooling.

1.6.2 Radiative cooling Principle: If two elements at different temperatures are kept facing one another, a net radiation heat loss from the hotter element will occur until a state of equilibrium between the two elements is achieved.

In order to have an appreciable net heat flux between the two bodies, the temperature difference should be significant

Low energy passive design stretegies in residential building typology in Bangalore city

Thermal comfort through out the year can be easily achieved in residential buildings in Bangalore by adopting the following passive design strategies:

• Long façade oriented towards North – South • East and West facades to be shaded • Solar chimneys integration to enhance natural ventilation • Insulated roof • Roof pond in certain areas for radiant cooling • Direct evaporative cooling 25 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

1.6.3 Some low energy cooling & design strategies that could be adopted in residential buildings in Bangalore are described below. These strategies were analysed in TRNSYS software.

1. Long façade oriented towards North South, this is based on the solar radiation analysis for Bangalore city. East and West façade receive higher intensity of solar radiation throughout the year and hence short facades of the building should be oriented towards East and West. This ensures minimum solar heat gain inside the building. 2. Insulated roof: Solar analysis of Bangalore predicts high intensity of solar radiation being received on horizontal surfaces. To reduce conduction gains from the roof, it is very esstial to insulate the roof from outside. 3. Solar chimneys to enhance natural ventilation, through stack effect. Inlet openings provided at lower level and outlet opening through solar chimney increase the temperature difference between the hot air and cool air, this enhances the air movement and therefore natural ventilation. Natural ventilation is very effective in Moderate climate of Bangalore as the outside air temperature falls under comfort zone. 4. Radiant cooling is also effectice in Bangalore and therefore roof pond could be provided wherever possible. 5. Evaporative cooling: In summer months in Bangalore which are April, May and June evaporative cooling is effective, as the outside temperature is high and Relative Humidity (RH) is lower. This can be integrated in buildings through evaporative coolers, or wet Khas Khas integrated around windows and through designing water bodies in the landscape.

1.7 Example of a Naturally Ventilated office Building in Bangalore

TERI’s South Regional office is located in Bangalore which forms an example of passive building in the Moderate climate zone of India.

Following are some of key features of the building: • The building is oriented with long facades oriented North– South. • The building has maximum openings in the North façade which helps bring inside the building glare free daylight and cool breeze. • The skylights are oriented towards North, which provides uniform glare free daylight through out the building. 26 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

• Walls on the South façade are externally finished with black kadappa stone with a cavity wall. This behaves as a solar chimney. There are no openings at lower level in this wall, only ventilators at the top of the wall are provided for hot air to rise and escape. This creates a negative pressure and starts pulling fresh cool air from North side of the building. The building works in natural ventilation mode through out the year, and this is achieved as there are no floor to ceiling partitions in the whole building. • There are roof gardens designed, which provide good insulation and moderates fluctuation in temperature. • The month bill for energy consumption is about Rs 30,000 for the entire complex, with daily average demand of 12 kW (peak at 18 kW). With floor area being 26,663 square feet, the specific energy bill works out to be Rs 1.12 per square foot, which is almost one tenth of a conventional building with air conditioning.

1.8 Summary: Recommendations for air conditioned buildings • Long façade preferably towards NorthSouth • East West façade to be shaded • Windows to comply with ECBC requirement. • Roof to either comply with ECBC or to be fully shaded. • Circular building form is preferable. • Light colour external finish.

1.8.1 Naturally ventilated buildings recommendations • Long façade preferably towards NorthSouth • East West façade to be shaded • Windows to be fully shaded. • Roof to be insulated or to be shaded. • Light colour external finish.

1.9 Glossary: Orientation : It is the direction an envelope element faces, i.e., the direction of a vector perpendicular to and pointing away from the surface outside of the element. Reflectance: The fraction of radiant energy that is reflected from a surface. Solar heat gain coefficient : Solar heat gain coefficient (SHGC) is the fraction of external solar radiation that is admitted through a window or skylight, both directly transmitted, and absorbed and subsequently released inward. Transmittance: The fraction of radiant energy that passes through a surface. 27 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

U-factor : It measures the rate of heat transfer through a building element over a given area, under standardised conditions. The usual standard is at a temperature gradient of 24 °C, at 50% humidity with no wind.

1.10 Reference: • Bureau of Indian Standards, 2005, National Building Code of India • A Knowledge Bank for Sustainable Building Design – CD, MNRE & TERI, New Delhi • Energy Conservation Building Code 2007, Bureau of Energy Efficiency, Ministry of Power, Government of India • VisualDOE version 4.1 Software • Ecotect Version 5.0.

Lighting Manufacturer contact details

SN Name Address Contact details Paint 1 THERMATEK (Ishaan ALA INC, No. 303,6th Main, Yellama Ph: 080 – 25352493 Industries) Temple Road, Indira Nagar, Bangalore Mobile: 9980560857 560038. 2 Kansai Nerolac Paints Nerolac House, SY No 39/1, P C S Ph: 08026597145 Limited Industrial Estate, Banner gata Road AREKER Village, Bangalore 560076

Insulation 3 U. P. Twiga Fiberglass No. 28/3 1st Floor, 23rd Cross, Ph: 08026712510 Limited Banashankari 2nd Stage Main Road, Mobile9686406229 Near State Bank of India, Bangalore 560070 4 Lloyd Insulations (India) 101102, Oxford Chamber, No. 16, Ph: 08025202084 Ltd Rustam Bagh Main Road, Bangalore: 560017 Glass Products 5 3M Construction Market Concorde block, UB City, 24, Vittal Malya Ph: 08066595759 Center Road, Bangalore560001 Fax: 08022231450

6 SaintGobain Glass Sai Comples, 4th Floor, 114, M G Road, Ph: 08025091123 India Ltd. Bangalore 560 001 Fax: 08025583795

GUIDELINES 2: Provide roof treatment to cut heat gains

Provide roof treatment to cut down heat gain in the airconditioned and naturally ventilated space to maximize thermal comfort.

2.1 Mandatory clause to be included in the Revised Bye Laws

All exposed roof in air conditioned spaces and naturally ventilated shall comply with the ECBC 2007 requirement as outlined below or shall be shaded Table 2.1: Roof assembly Ufactor requirements as per ECBC 2007 Climate 24Hour use buildings Daytime use buildings zone Hospitals, Hotels, Call centres etc. Other building Types Maximum Ufactor of the overall assembly (W/m 2K) Maximum Ufactor of the overall assembly(W/m 2K) Moderate U0.409 U409

The roof insulation shall not be located on a suspended ceiling with removable Ceiling panels. (Mandatory)

2.2 Technical Guidance

2.2.1 Brief Introduction Optimizing roof material can play vital role in lowering down heat built up in both air conditioned space and naturally ventilated space. Roof treatment is one of the effective strategies to cut down heat gain helps in reducing cooling load from air conditioned space. In the same way, it helps in maximizing thermal comfort in naturally ventilated space.

Roof optimization in Air Conditioned Space: It is observed in air conditioned buildings, adopting ECBC envelope in building has high energy saving potential. Energy simulation engine was used to quantify energy saving potential in a daytime office building. . It is observed that in single storey buildings and in double storey buildings, insulated + cool roof as recommended by ECBC has energy saving potential up to 60% in comparison to conventional buildings. This saving potential however, reduces with increase in number of floors and in case of high rise buildings, where roof contribution towards external heat gains is minimized

Roof Composition (External to internal) U value (W/m2K) ECBC compliant Roof finish+75mm Expanded Polystyrene+150mm Concrete slab + internal plaster 0.39 insulated + cool roo Conventional case Roof finish +150mm concrete slab + internal plaster 1.81

Shading of roof also has similar energy saving potential. This could be achieved by designing pergolas, trellis on roof or by installation of solar panels. Energy saving potential in a building with two floors and built up area 3200m2, after complying to ECBC recommendations and shading the roof are given below in the graph. 29 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Energy use in conventional building, building with ECBC compliant roof, building with shaded roof

1,200,000 1,000,000 800,000

600,000 61% saving 62% saving 400,000 200,000 0 Energy (kWh) use base 0.30wwr ECBC + cool roof Shaded roof

0.30wwr 0.30wwr

Energy consumption kWh (Cooling+Lighting)

Recommended roof treatment for Naturally Ventilated spaces Thermal comfort in a naturally ventilated space can be maximized by using appropriate treatment for the roof. Computer simulation analysis was performed in order to investigate the role of roof treatment to maximize thermal comfort in a naturally ventilated space. Following are envelope configuration used for simulation analysis

Roof Composition (External to internal) U value (W/m2K) ECBC case Roof finish+75mm Expanded Polystyrene+150mm Concrete slab + internal plaster 0.39 Conventional case Roof finish +150mm concrete slab + internal plaster 1.81

Glass Type Properties ECBC case (Single glazed Uvalue =6.16 W/m2K , SHGC = 0.81 , VLT = 0.88 unit) Conventional case (Single Uvalue =6.16 W/m2K , SHGC = 0.81 , VLT = 0.88 glazed unit)

The thermal comfort hours are further maximized when the surface reflectivity increased to 0.7 y using white paint on external roof surface and insulation thickness.

30 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

2.2.2 Heat gains through roofs can be reduced by adopting the following techniques

Green roof concept Green roofs have the potential to improve the thermal performance of a roofing system through shading, insulation, evapotranspiration and thermal mass, thus reducing a building’s energy demands for space conditioning. The green roof moderates the heat flow through the roofing system and helps in reducing the temperature fluctuations due to changing outside environment. Figure 2.1: Roof of buildings with roof garden. 31 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Use of high reflective material on roof top Use light coloured roofs having an SRI (solar reflectance index) of 50% or more. The dark coloured, traditional roofing finishes Figure 2.2 : Broken china mosaic can be used as have SRI varying from 5 20%. A good example of high SRI is an external roof finish to reflect the incident solar radiation. the use of broken china mosaic and light coloured tiles as roof finish, which reflects heat off the surface because of high solar reflectivity and infrared emittance, which prevents heat gain and thus help in reducing the cooling load from the building envelope.

Table 2.2: Roof assembly Ufactor requirements as per ECBC 2007 Climate zone 24Hour use buildings Daytime use buildings Hospitals, Hotels, Call centres etc. Other building Types Maximum Ufactor of the overall assembly (W/m 2K) Maximum Ufactor of the overall assembly (W/m 2K) Moderate U0.409 U409

Insulation + cool roof Along with lower Uvalue for roof, ECBC also recommends cool roof. Cool roofs are roofs covered with a reflective coating that has high emissivity property which is very effective in reflecting the sun’s energy away from the roof surface. These cool roofs are known to stay 10 °C to 16 °C cooler than normal roof under a hot summer day. This quality greatly helps in reducing the cooling load that needs to be met by the HVAC system. Combination of insulated roof along with cool roof has higher saving energy potential.

32 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Thermal properties of few building and insulating materials for reference are given below in table 2.3.

Table 2.3: Thermal Properties of Building and Insulating Materials at Mean Temperature of 50deg.C SL. NO. TYPE OF MATERIAL DENSITY THERMAL CONDUCTIVITY* SPECIFIC HEAT CAPACITY (1) (2) (3) (4) (5) Kg / m3 W / (m.K) KJ / (kg.K) Building Materials 1. Burnt brick 1 820 0.811 0.88 2. Mud brick 1 731 0.750 0.88 3. Dense concrete 2 410 1.74 0.88 4. R.C.C. 2 288 1.58 0.88 5. Limestone 2 420 1.80 0.84 6. State 2 750 1.72 0.84 7. Reinforced brick 1 920 1.10 0.84 8. Brick tile 1 892 0.798 0.88 9. Line concrete 1 646 0.730 0.88 10. Mud Phuska 1 622 0.519 0.88 11. Cement mortar 1 648 0.719 0.92 12. Cement concrete 1 762 0.721 0.84 13. Cinder concrete 1 406 0.686 0.84 14. Foam slag concrete 1 320 0.285 0.88 15. Gypsum plaster 1 120 0.512 0.96 16. Cellular concrete 740 0.188 1.05 17. AC sheet 1 520 0.245 0.84 18. GI sheet 7 520 61.06 0.50 19. Timber 480 0.072 1.68 20. Timber 720 0.144 1.68 21. Plywood 640 0.174 1.76 22. Glass 2 350 0.814 0.88 23. Alluvial clay (40 percent sans) 1 958 1.211 0.84 24. Sand 2 240 1.74 0.84 33 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

25. Black cotton clay (Madras) 1 899 0.735 0.88

26. Black cotton clay (Indore) 1 683 0.606 0.88

27. Tar felt (2.3 kg/m3) 0.479 0.88 (Source, Handbook on Functional Requirements of buildings, SP:41—1987, BIS)

SL. NO. TYPE OF MATERIAL DENSITY THERMAL CONDUCTIVITY* SPECIFIC HEAT CAPACITY (1) (2) (3) (4) (5) Kg / m3 W / (m.K) KJ / (kg.K) Insulating Materials 1. Expanded polystyrene 16.0 0.038 1.34 2. Expanded polystyrene 24.0 0.035 1.34 3. Expanded polystyrene 34.0 0.035 1.34 4. Foam glass 127.0 0.056 0.75 5. Foam glass 160.0 0.055 0.75 6. Foam concrete 320.0 0.070 0.92 7. Foam concrete 400.0 0.084 0.92 8. Foam concrete 704.0 0.149 0.92 9. Cork slab 164.0 0.043 0.96 10. Cork slab 192.0 0.044 0.96 11. Cork slab 304.0 0.055 0.96 12. Rock wool (unbonded) 92.0 0.047 0.84 13. Rock wool (unbonded) 150.0 0.043 0.84 14. Mineral wool (unbonded) 73.5 0.030 0.92 15. Glass wool (unbonded) 69.0 0.043 0.92 16. Glass wool (unbonded) 189.0 0.040 0.92 17. Resin bonded mineral wool 48.0 0.042 1.00 18. Resin bonded mineral wool 64.0 0.038 1.00 19. Resin bonded mineral wool 99.0 0.036 1.00 20. Resin bonded glass wool 16.0 0.040 1.00 21. Resin bonded glass wool 24.0 0.036 1.00 22. Exfoliated vermiculite 264.0 0.069 1.00 (loose) 23. Asbestos mill board 1 397.0 0.249 0.88 24. Hard board 979.0 0.279 0.84 25. Straw board 310.0 0.057 1.42 26. Soft board 320.0 0.066 1.30 27. Soft board 249.0 0.047 1.30 28. Wall board 262.0 0.047 1.30 29. Chip board 432.0 0.067 1.26 30. Chip board (perforated) 352.0 0.066 1.26 31. Particle board 750.0 0.098 1.30 34 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

32. Coconut pith insulation 520.0 0.060 1.09 board 33. Jute fibre 329.0 0.067 1.09 34. Wood wool board 398.0 0.081 1.13 (bonded with cement) 35. Wood wool board 674.0 0.108 1.13 (bonded with cement) 36. Coil board 97.0 0.038 1.00 37. Saw dust 188.0 0.051 1.00 38. Rice husk 120.0 0.051 1.00 39. Jute felt 291.0 0.042 0.88 40. Asbestos fibre (loose) 640.0 0.060 0.84

2.2.3 Why is this required? Roof receives a significant amount of solar radiation round the year. As illustrated in Fig 1, shows the intensity of solar irradiation is maximum on the horizontal plane which is the roof. Conductance of heat from the roof can be very high if not insulated well.

Figure 2.3: Average daily Intensity of solar radiation incident on horizontal roof surface in Bangalore

This can result in increased cooling load if the space below is air conditioned or high discomfort hours if the space below is naturally ventilated.

2.2.4 How is it beneficial? Treatment of roof in the form of roof insulation reduces cooling demand from air conditioning and related energy consumption in aircondition and helps in maximizing thermal comfort in nonairconditioned spaces. Application of insulation on roof can bring down energy consumption in airconditioned spaces below roof.

35 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Energy modeling has been carried out to quantify energy saving potential of roof insulation and life cycle analysis has been carried out to calculate payback period for applying roof insulation in a day use office air conditioned building. It has been observed that due to high energy saving in single or double storey building after complying with ECBC thermal performance of the roof, pay back period in Bangalore will be less than one year.

LCCA of conventional buildings and ECBC compliant roof building

200

150 Millions 100

Cost (Rs) Cost 50

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Years

Base case ECBC + cool roof case

In naturally ventilated buildings, roof insulation brings positive impacts on thermal comfort of non airconditioned naturally ventilated spaces and can bring down the number of discomfort hours. Simulation using energy modeling was carried out to quantify reduction in discomfort hours. It has been observed that, the internal space under the insulated roof having high reflectivity, registers a 1 °C drop in temperature compared to conventional roof.

The graphical illustration shows that insulated roof works better in Moderate Climate of Bangalore showing a temperature drop of 1 °C at peak hour of Day in April 11 which is regarded as the hottest day in Summer season.

36 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

ZONE TEMPERATURE COMPARISION IN AN OFFICE SPACE WITH DIFFERENT ROOF TYPES

uninsulated roof insulated roof with high reflectivity

34.00

33.00 32.00

31.00 30.00

29.00 28.00

27.00

TEMPERATURE (deg TEMPERATURE C) (deg 26.00 25.00

24.00 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 HOURS

2.3 Glossary:

Extruded Polystyrene Extruded Polystyrene is an improvement of Expanded Polystyrene material. This material is also comprised of beads / globules which are compressed to form slabs and pipe sections. Incase of Extruded Polystyrene the beads are very closely linked to each other so that the material become rigid and there is no air gap between the beads. It is a close cells material and a skin is formed on the top which stops water absorption.

2.4 References:

National Building Code of India 2005 SP41: Handbook of Functional Requirement of Buildings TRNSYS 16 software

GUIDELINE 3: Window Design

3.1 For airconditioned buildings

1. *The Ufactor (overall heat transfer coefficient) for a fenestration product (including the sash and frame) should be determined as per ECBC 2007 requirements. 2. *The SHGC (solar heat gain coefficient) for a fenestration product (including the sash and frame) should be determined as per ECBC 2007 requirements. 3. The Ufactor and SHGC for the fenestration product determined as per §1 and §2, should confirm to the ECBC 2007 recommended values given in the table 3.1 ,3.2 below for vertical and horizontal fenestrations –

Table3.1: For vertical fenestration Maximum Ufactor (W/m 2 Maximum SHGC for Maximum SHGC for Climate K) WWR ≤ 40% 40%

Table 3.2: For horizontal fenestration

Maximum Ufactor (W/m 2K) Maximum SHGC Climate With Curb Without Curb 02% SRR 2.15% SRR

Moderate 11.24 7.71 0.61 0.4

Note – SRR = Skylight roof ratio which is the ratio of the total skylight area of the roof, measured to the outside of the frame, to the gross exterior roof

4. Air leakage through fenestration shall not exceed the ECBC 2007 recommended value of 2.0 l/sm2 5. The minimum Window Wall Ratio on a facade, correlated to the visible light transmittance of the glass should be read from the graph given below for different Height to Separation ratios for building – 38 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

For Various H:S, VLT and WWR H:S - 1:5 H:S - 1:4 H:S - 1:3 H:S - 1:2 H:S - 1:1 90

50 VLT 40

0 20% 30% 40% 50% 60% WWR

Note: If the window area for WWR value for a space, read from the graph above, is less than 1/5th of the floor area, then minimum window area which should be provided will be taken as 1/5th of the floor area.

6. *The maximum permissible WWR on a facade should not exceed 60% as recommended in ECBC,2007 *are all mandatory clauses

3.2 For Nonconditioned buildings

1. In the nonconditioned buildings, penetration of direct solar radiation needs to be regulated. The critical Horizontal Solar Angle (HSA) and Vertical Solar Angle(VSA) for fenestrations located on the cardinal directions (as shown in the figure) given below in the table should be cut down by designing appropriate shading devices –

Table 3.3: Solar Angles Solar Angles to be cut on various cardinal directions HSA (Horizontal Sun Angle) in VSA (Vertical Solar Angle) in Cardinal Directions Degrees Degree North 37.8 79.4 East 1 33.2 West 5.9 58 South 68.9 85.1 NorthEast (NE) 44 42.3 NorthWest (NW) 50.9 68.3 SouthEast (SE) 46 43.3 SouthWest (SW) 39.1 64 Note – 39 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

o Angles have been measured from the normal to the fenestration o Angles measured anticlockwise from the normal of the fenestration have been shown with negative sign for HSA (horizontal sun angle)

2. The minimum Window Wall Ratio on a facade, correlated to the different Height to Separation ratios for nonconditioned commercial and residential buildings should be read from the table given below (with clear glass)–

Table 3.4 : For nonconditioned commercial buildings H/S ratio Minimum WWR (%)required for adequate (height to separation between buildings) day lighting 1:5 20 1:4 20 1:3 20 1:2 20 1:1 20

Table 3.5: For nonconditioned residential buildings H/S ratios Minimum WWR (%)Required for (height to separation between buildings) adequate day lighting 1:5 10 1:4 10 1:3 10 1:2 20 1:1 20 2:1 50 3:1 60

Note: If the window area for WWR value for a space, read from the table above, is less than 1/5th of the floor area, then minimum window area which should be provided will be taken as 1/5th of the floor area.

3. *The maximum permissible WWR on a facade should not exceed 60% as recommended in ECBC,2007 *are all mandatory clauses

4. Guideline for Ventilation Optimize window design to integrate natural ventilation inside the built environment. It is mandatory to meet the thermal comfort parameters specified in National Building code 2005 for naturally ventilated spaces and minimum air change per hour specified in SP41: Handbook on Functional Requirement of Buildings.

5. Window opening requirement for Naturally ventilated Low rise Residential and Office Buildings a. Window openings, in order to allow outside air to enter the space, should orient between 45 ° to the EastWest direction to optimize heat and solar heat gain b. Location of window openings, in order to facilitate cross ventilation, should be located opposite to each other on walls parallel to each other. The location of windows should be preferably on east and west wall functioning as inlet and outlet openings to maximize ventilation of the space. 40 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

c. The inlet and outlet openings, when added up, should be in the range of 2756% of the floor area of that space and window wall ratio (WWR) in the range of 18 36 %, or whichever is critical. d. In order to achieve the required air change per hour in a given space, use cross ventilation and stack ventilation mode of natural ventilation.

6. Window opening requirement for naturally ventilated Highrise Residential and Office Buildings

Highrise buildings, with height going beyond 10m or Ground plus floor storey, opening area should follow the table as given below:

Table 3.6 : Opening area for naturally ventilated space in high rise building Acceptable Percentage of Area of Building Height Opening with respect to floor area (m) (%) 10 3.19 1.60 13 2.91 1.46 16 2.71 1.35 19 2.55 1.27 22 2.42 1.21 25 2.32 1.16 28 2.23 1.11 31 2.15 1.07 34 2.08 1.04 37 2.02 1.01 40 1.96 0.98 43 1.91 0.96 46 1.870.94 49 1.83 0.91 52 1.79 0.90 55 1.76 0.88 58 1.72 0.86 61 1.69 0.85 64 1.67 0.83 67 1.64 0.82 70 1.61 0.81 73 1.59 0.80 76 1.570.78 79 1.55 0.77 82 1.53 0.76 85 1.51 0.75 88 1.49 0.75 91 1.47 0.74 94 1.46 0.73 97 1.44 0.72 41 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

100 1.43 0.71

3.3 Guidance Notes

3.3.1 Windows in AirConditioned buildings Window (including both glazing and frame) in an airconditioned space is an important element to be analyzed with respect to its thermal performance and impact on energy performance of that particular space. Window impacts the energy performance of a conditioned space in two ways – 1. Impact on the HVAC energy consumption of the building 2. Impact on the Lighting energy consumption

Impact on HVAC energy consumption of building There are three major types of energy flow which occur through a window which impacts the HVAC energy consumption –

1. Non-solar heat losses and gains in the form of conduction, convection, and radiation - The nonsolar heat flow through a window occurs due to the temperature difference between the indoor and outdoor. Window loses heat to the outside during the winter season and gains heat from the outside during the summer season, adding to the energy needs in a building.

2. Solar heat gains in the form of radiation-The direct solar radiation entering into a conditioned space adds to the cooling load in summers and reduces heating load in winters in a building.

3. Infiltration Infiltration is the uncontrolled leakage of air into a space from the outside through joints and cracks around window frame, sash, and glazing. The air tightness of a window depends on both the characteristics of the window—such as sash type and overall quality of window construction—and the quality of the installation.

42 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Given below are various parameters, related to the thermal performance, of a window which should be appropriately selected to achieve energy efficiency in a air conditioned building –

Ufactor of fenestration Ufactor is a measure of the rate of nonsolar heat flow through a window per unit area per unit temperature difference between indoor and outdoor.

The Ufactor of a single pane window is mainly due to the thin films of still air on the interior and moving air on the exterior glazing surfaces. The glazing itself doesn’t offer much resistance to heat flow. Additional panes if added can noticeably reduce the Ufactor by creating still air spaces.

In addition to conventional doublepane windows, many manufacturers offer windows that incorporate relatively new technologies aimed at decreasing Ufactors. These technologies include lowemittance (lowE) coatings and gas fills.

A lowE coating is a microscopically thin, virtually invisible, metal or metallic oxide coating deposited on a glazing surface. The coating may be applied to one or more of the glazing surfaces facing an air space in a multiplepane window. The coating limits radiative heat flow between panes by reflecting heat back.

The airgap between windowpanes can be filled with gases which have better thermal resistance property than air such as argon, krypton etc.

Window frames are usually made of aluminum, steel, wood, vinyl, fiberglass, or composites of these materials. Wood, fiberglass, and vinyl frames are better insulators than metal. Some frames are designed with internal thermal breaks that reduce heat flow through the frame. These thermally broken frames can resist heat flow considerably better than those without thermal breaks.

SHGC (solar heat gain coefficient) of fenestration The SHGC is the fraction of incident solar radiation admitted through a window, both directly transmitted, and absorbed and subsequently released 43 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City inward through conduction, convection and radiation.

Additional glazing layers provide more barriers to solar radiation, thus reducing the solar heat gain coefficient of a window. Tinted glazings, such as bronze and green, provide lower solar heat gain coefficients compared to the clear glass. Spectrally selective glazings, including some lowE coated glazings with low solar heat gain, blocks out much of the sun’s heat while maintaining higher visible transmittances.

Shading and Adjusted SHGC Exterior or interior shading devices such as awnings, louvered screens, sunscreens, venetian blinds, roller shades, and drapes can complement and enhance the performance of windows with low Solar Heat Gain Coefficients. One advantage of many shading devices is that they can be adjusted to vary solar heat transmission with the time of day and season.

Exterior shading devices are more effective than interior devices in reducing solar heat gain because they block radiation before it passes through a window. Lightcolored shades are preferable to dark ones because they reflect more, and absorb less, radiation.

Projection Factor For horizontal overhang Projection factor for overhang is calculated by measuring the depth of the overhang and dividing that by the distance from the bottom of the window to the lowest point of the overhang.

For vertical fins Projection factor for vertical fin is calculated by measuring depth of the vertical fin and dividing it by the distance from the window jamb to the farthest point of the external shading projection.

SHGC for a window having an external shading device can be calculated by multiplying the SHGC value of the window with the ‘M’ factor read from the table given below for different projection factors for different orientations.

Overhang 'M' factor for the Vertical Fin 'M' factor for Overhang + Vertical Fin 'M' projection factor projection factor factor for projection factors 0.25 0.5 0.75 0.25 0.5 0.75 0.25 0.5 0.75 Location Orientation 0.49 0.74 0.99 1.0 + 0.49 0.74 0.99 1.0 + 0.49 0.74 0.99 1.0 + North N 0.88 0.8 0.76 0.73 0.74 0.67 0.58 0.52 0.64 0.51 0.39 0.31 Latitude 15 0 or E/W 0.79 0.65 0.56 0.5 0.8 0.72 0.65 0.6 0.6 0.39 0.24 0.16 greater S 0.79 0.64 0.52 0.43 0.79 0.69 0.6 0.56 0.6 0.33 0.1 0.02 Less N 0.83 0.74 0.69 0.66 0.73 0.65 0.57 0.5 0.59 0.44 0.32 0.23 44 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City than 15 0 E/W 0.8 0.67 0.59 0.53 0.8 0.72 0.63 0.58 0.61 0.41 0.26 0.16 North Latitude S 0.78 0.62 0.55 0.5 0.74 0.65 0.57 0.5 0.53 0.3 0.12 0.04

Impact on Lighting energy consumption During day time when natural light, in outside, is available in abundance, window can be utilized as a tool to harness natural light from sun and sky to light the space. Buildings, in which artificial lighting is integrated with the day lighting, can reduce their energy bills significantly. Good day lighting in a building depends upon the following factors –

Window Wall Ratio (WWR) Window wall ratio is the ratio of window area to the gross wall area for a particular facade. Gross wall area includes both the window area and the area of the wall surface.

Example – The wall shown in the figure has width ‘W’ and height ‘H’. The window height is ‘a’ and width is ‘b’ as shown in figure.

The WWR for the given facade will be = (a x b)/(H x W)

VLT (Visible Light Transmittance) of glazing It is the ratio of the visible light getting transmitted through the glazing to the total visible light incident on the glazing.

Higher the value of VLT, more will be the amount of day light entering into the space through glazing.

Daylighting and Window Design Day lighting is utilization of light from the sun and sky to complement or replace electric light. Appropriate fenestration and lighting controls can be used to modulate daylight admittance and to reduce electric lighting, while meeting the occupants’ visual comfort.

Daylight Perimeter Zone for Vertical Fenestration – The day lighter zone associated to a window can be defined as an area having a depth which is twice the window height (measured from ground) and having the width 45 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City which is equal to the window width plus one meter on each of the window as indicated in the figure below –

Day lighted perimeter zone for the space shown above will be having dimensions –

Depth (m) = 2 x Y Width (m) = X + 1 +1

The fenestration area, located above 1m but below 2.2 m is considered as vision window area. The vision window area is usually provided with the glass with lower VLT in order to reduce glare.

The fenestration area located above 2.2 m is considered as daylight window area. Larger the daylight window area more will be the daylight penetration into a space. The daylight window area is usually provided with glass with higher VLT so as to receive daylight to the greater depths of the space.

The daylight window area can be designed in form of light shelves, as shown in the figure above, which enhance the penetration of daylight.

46 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

When there are buildings standing opposite to each other the amount of daylight entering through the window gets reduced.

For different height to the separation ratio (H/S) for buildings one an choose the minimum WWR and VLT from the graph given below to achieve good day light in the space –

For Various H:S, VLT and WWR H:S - 1:5 H:S - 1:4 H:S - 1:3 H:S - 1:2 H:S - 1:1 90 80 70 60

50 VLT 40

30 20 10 0 20% 30% 40% 50% 60% WWR

3.3.2 Windows in NonConditioned building Window design in nonconditioned buildings takes a different approach. The glazing system for windows in nonconditioned spaces is usually single glazed units with clear glass as the windows will be opened to allow ventilation thus there is no relevance to install double glazing with low SHGC and Ufactor values. In the nonconditioned buildings the shading device plays a crucial role in the thermal performance of a 47 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City window. Windows on facades, facing different cardinal directions, should be provided by the shading devices which can cut the direct incident solar radiation for the critical solar angles.

Horizontal Sun Angle (HSA) This is the horizontal angle between the normal of the window and the Sun azimuth angle at a given time as shown in the figure.

The horizontal sun angle at critical hours can be cut by the vertical fins provided as external shading device.

Vertical Solar Angle (VSA) It is the angle that a plane containing the bottom two points of the window and the centre of the Sun makes with the ground when measured normal to the shaded surface as shown in the figure.

The vertical solar angle at critical hours can be cut by the horizontal fins provided as external shading device.

Shading Devices The external shading devices can be designed in various ways to stop the solar radiation entering through the window. The figures of the commonly found shading devices are given below –

Example to design shading device for a window For a window of height 1.5 m and width 3m, design shading device to cut the HSA of 45 0 and VSA of 60 0.

Design of shading device to cut the VSA The vertical solar angle of 60 0 can be cut by providing a single horizontal overhang of length 841mm or it can be cut by providing two horizontal projections each of length 48 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

408mm placed at a distance of 750mm as shown in the figure.

The length and spacing can be calculated either by the drafting softwares like autocad, sketchup etc. by graphical method or it can be manually calculated by the mathematical formula given below –

Depth of shading device = Spacing between the shading device x {tan (90 VSA)}

For a given VSA either of the values for Depth or Spacing between shading overhangs can be selected to get the value of other one.

Design of shading device to cut the HSA The horizontal solar angle of 45 0 can be cut by providing a single vertical fin of length 2907mm or it can be cut by providing four vertical fins each of length 657mm placed at a distance of 657mm as shown in the figure.

The length and spacing can be calculated either by the drafting softwares like autocad, sketchup etc. by graphical method or it can be manually calculated by the mathematical formula given below –

Depth of vertical fins = Spacing between the vertical fins x {tan (90 HSA)}

For a given HSA either of the values for Depth or Spacing between vertical fins can be selected to get the value of other one.

It is always desirable to break single overhang with larger depth into multiple overhangs of smaller length. It enhances the amount of daylight penetration in the space. The figure in right shows the comparison between amount of daylight penetration for two shading devices, one with 49 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City single deep overhang and the other with multiple smaller overhangs.

Day lighting and WWR To get the adequate daylight in a commercial nonconditioned building one can choose for different Height to separation ratio the required WWR while installing a clear glass from the table given below –

H/S ratio Minimum WWR (%)required for (height to separation between buildings) adequate day lighting 1:5 20 1:4 20 1:3 20 1:2 20 1:1 20

To get the adequate daylight in a residential nonconditioned building one can choose for different Height to separation ratio the required WWR while installing a clear glass from the table given below –

H/S ratios Minimum WWR (%)Required (height to separation between buildings) for adequate day lighting 1:5 10 1:4 10 1:3 10 1:2 20 1:1 20 2:1 50 3:1 60

Example of H/S ratio related to WWR for a nonconditioned residential building

Calculate minimum WWR, needs to be provided, on a face of the wall of a building which is 18m high. There exists another building of same height opposite to the given facade at a distance of 9m.

The H/S ratio for the building = Height/ Separation = 18/9 = 2/1 So for the H/S ratio of 2:1 the minimum WWR, to be provided on a face for adequate day lighting in the space, value read from table given above comes to be 50 %. 50 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

3.3.3 Window Design for Natural ventilation Windows are required to achieve natural cooling through ventilation. Optimized window design plays a vital role in the building envelope to reduce the annual energy consumption both for lighting and air conditioning. Optimized window design helps to achieve thermal comfort with no additional financial investment. Optimized window design helps to reduce dependence on air conditioning where natural ventilation is possible and helps in reducing discomfort in naturally ventilated spaces. Technical guidance, to meet the optimized window opening size for acceptable air change per hour and thermal comfort, can be achieved by following simple steps as outlined below:

Naturally ventilated Low rise Residential and Office Buildings i. Perform detailed literature analysis for residences and office in order to meet the mandatory thermal comfort and air change per hour as outlined in National Building Code 2005 and SP41: Handbook for Functional Requirements of Buildings (except industrial buildings)

Table 3.7: Desirable Wind speed (m/s) for Thermal Comfort Conditions: Clause 5.2.3.1, National Building Code 2005 Dry bulb Relative humidity (%) temperature (deg C) 30 40 50 60 70 80 90 28 * * * * * * * 29 * * * * * 0.06 0.19 30 * * * 0.06 0.24 0.53 0.85 31 * 0.06 0.24 0.53 1.04 1.47 2.10 32 0.20 0.46 0.94 1.59 2.26 3.04 ** 33 0.77 1.36 2.12 3.00 ** ** ** 34 1.85 2.72 ** ** ** ** ** 35 3.20 ** ** ** ** ** **

Table 3.8: Air change schedule SP41: Handbook on Functional Requirement of Buildings

Space to be ventilated in Required air change per hour Residence Bedrooms 36 Living rooms 36 Offices 36

ii. Perform thermal comfort analysis using recommended air change per hour and opening size and compare the results with the above mentioned codes. Envelop requirements for the space can be used as mentioned below:

Table 3.9: Envelope Specifications Envelope with brick wall Composition Uvalue Wall Plaster + brick + plaster 2.203 Roof Plaster + concrete + expanded 0.349 51 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

polystyrene + plaster + stone Floor Floor + stone + concrete + insulation 0.417 Glass for opening Single clear glass

Envelope with concrete Composition Uvalue wall Wall Plaster + concrete + plaster 3.443 Plaster + concrete + expanded Roof 0.349 polystyrene + plaster + stone Floor Floor + stone + concrete + insulation 0.417 Glass for opening Single clear glass

The detailed properties of the above mentioned envelopes can be found in the annexure.

iii. The design of the windows must facilitate easy operation and should help in regulating the amount of opening as mentioned in the guidelines.

iv. Difference between window area and opening area: Window area represents the overall area of operable and fixed area of the opening. Opening area represents the area which will admit air into the space for ventilation

Image to illustrate window and opening area and option to operate

v. Design of the window must facilitate operation of the window with ease. In the above image it has been shown that, sliding window can be one of the options for such operations. vi. When cross ventilation and stack ventilation is used to enhance the air change per hour, the total area of the opening should be in the range as specified in the guideline. vii. Conditions where outside air temperature exceeds the indoor temperature conditions, only stack ventilation mode should be used.

Naturally ventilated High-rise Residential and Office Buildings

i. Wind speed analysis with increasing height of the building should be analyzed in detail. 52 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

ii. Opening size in the window must be coherent with the wind speed achieved at a particular height as shown in the figure below.

iii. The recommended area of opening must follow all the design recommendation as outlined in the technical guidelines for naturally ventilated Low rise Residential and Office Buildings.

Generic Guidelines for Natural Ventilation Design i. Natural ventilated buildings in Bangalore should take advantage of the predominant wind originating from east and west direction to maximize cross ventilation. ii. Stack ventilation can be enhanced by providing openings on the opposite side of the wall, where the inlet opening should be located at the bottom most part of the wall and outlet openings should be on the topmost part of the wall in order to increase the height difference between two. 53 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

iii. Naturally ventilated buildings should have a narrow floor width; in fact it’s difficult to naturally ventilate buildings with floor depth more than 45feet. iv. For total area of openings (inlet and outlet) of 20 to 30% of floor area, the average indoor wind velocity that could be achieved is around 30% of outdoor wind velocity. Even on increasing the size of window further, the maximum indoor wind velocity does not exceed 40% of outside wind velocity v. It is recommended to keep the bottom side of the opening at 85 % of the critical height related with following pattern of activities and related occupancy to enhance physiological cooling.

Table 5: Critical Height requirement for Physiological cooling

Activities based occupancy Recommended height of the bottom side of opening For sitting on chair 0.75 m For sitting on bed 0.60 m For sitting on floor 0.40 m.

vi. Use of clerestories or vented skylights, a clerestory or a vented skylight will provide an opening for stale air to escape in a buoyancy ventilation strategy. The light well of the skylight could also act as a solar chimney to augment the flow. Openings lower in the structure, such as basement windows, must be provided to complete the ventilation system.

54 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

3.4 Glossary

U-factor: It measures the rate of heat transfer through a building element over a given area, under standardized conditions. The usual standard is at a temperature gradient of 24 °C, at 50% humidity with no wind.

Orientation: It is the direction an envelope element faces, i.e., the direction of a vector perpendicular to and pointing away from the surface outside of the element.

Natural Ventilation: Supply of outside air into a building through window or other openings due to wind outside and convection effects arising from temperature or vapour pressure differences (or both) between inside and outside of the building.

Stack Effect: Convection effect arising from temperature or vapour pressure difference (or both) between outside and inside of the room and the difference of height between the outlet and inlet openings.

3.5 References

• Bureau of Indian Standards, 1987, Handbook on Functional Requirements of Buildings • National Building Code 2007 • Sustainable Architectural Design for Bioclimatic High rise Office Building by Ms Minni Mehrotra, MA Dissertation September 2004

55 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Annexure Details of Envelops: Envelope with Brick wall WALL Conductivity Specific Heat Capacity Density Thickness UValue Materials W/m. k kJ/kg . K Kg/m 3 (mm) W/m 2K Plaster 1.39 1 200 15 Brick 0.89 1 1800 230 2.203 Plaster 1.39 200 20 Total thickness 265 mm ROOF Conductivity Specific Heat Capacity Density Thickness UValue Materials W/m. k kJ/kg . K Kg/m 3 (mm) W/m 2K Plaster 1.39 1 200 15 Concrete 2.08 0.8 2400 300 Expanded 1.47 25 100 polystyrene 0.04 0.349 plaster 1.39 1 200 40 stone 1.39 1 2000 20 Total thickness 475 mm GROUND FLOOR Conductivity Specific Heat Capacity Density Thickness UValue Materials W/m. k KJ/kg. K Kg/m 3 (mm) W/m 2K Floor 0.07 1 800 5 Stone 1.39 1 2000 60 concrete 2.08 0.8 2400 240 0.417 insulation 0.04 0.8 40 80 Total thickness 385 mm Envelop with concrete wall: WALL Conductivity Specific Heat Capacity Density Thickness UValue Materials W/m. k kJ/kg . K Kg/m 3 (mm) W/m 2K Plaster 1.39 1 200 15 Concrete 2.08 0.8 2400 230 3.282 Plaster 1.39 1 200 20 Total thickness 265 mm ROOF Conductivity Specific Heat Capacity Density Thickness UValue Materials W/m. k KJ/kg. K Kg/m 3 (mm) W/m 2K Plaster 1.39 1 200 15 Concrete 2.08 0.8 2400 300 Expanded 1.47 25 100 polystyrene 0.04 0.349 plaster 1.39 1 200 40 stone 1.39 1 2000 20 Total thickness 475 mm GROUND FLOOR Conductivity Specific Heat Capacity Density Thickness UValue Materials W/m. k kJ/kg . K Kg/m 3 (mm) W/m 2K Floor 0.07 1 800 5 Stone 1.39 1 2000 60 concrete 2.08 0.8 2400 240 0.417 insulation 0.04 0.8 40 80 Total thickness 385 mm GUIDELINE 4: Energy Efficiency in Artificial Lighting

4.1 Interior Lighting

4.1.1 For Buildings with connected electrical load more than 100 kW • *The installed interior lighting power should not exceed the LPD (lighting power density) value as recommended by Energy Conservation Building Code 2007 (applicable for all new and existing commercial buildings) • *Install lighting controls as recommended by ECBC 2007 (applicable for all new and existing commercial buildings) • Select lamps with high Colour Rendering Index (CRI). • Lamps – Lamps used for general lighting scheme should comply to the following o Point Light Source – All the point light sources installed in the building for general lighting should be CFL or LED based with minimum lamp efficacy of 50 lm/W o Linear Light Source – All the linear light sources installed in the building for general lighting should be T5 or at least 4 Star BEE rated TFLs (applicable for all new and existing commercial buildings)

• *Ballasts – All the ballasts installed (including those integrated in CFLs) should be electronic or low loss copper ballasts (applicable for all new and existing commercial buildings)

*are mandatory criteria

4.1.2 For Residential Buildings • *The installed interior lighting power should not exceed the LPD (lighting power density) value as recommended by Energy Conservation Building Code 2007 (applicable for all new and existing residential buildings) • Install lighting controls as recommended by ECBC 2007 (applicable for all new and existing commercial buildings) • Select lamps with higher Colour Rendering Index (CRI) • Lamps – Lamps used for general lighting scheme should comply to the following o Point Light Source – All the point light sources installed in the building for general lighting should be CFL or LED based with minimum lamp efficacy of 50 lm/W o Linear Light Source – All the linear light sources installed in the building for general lighting should be T5 or at least 4 Star BEE rated TFLs (applicable for all new and existing residential buildings) 57 Guidelines for Energy Efficiency in Artificial lighting

• *Ballasts – All the ballasts installed (including those integrated in CFLs) should be electronic or low loss copper ballasts (applicable for all new and existing residential buildings)

*are mandatory criteria

4.2 Exterior Lighting

4.2.1 Commercial & Residential Buildings • The installed exterior lighting power density for the respective applications should be in accordance with ECBC 2007 • *Install lighting controls as recommended by ECBC 2007 for external lighting • *Lamps – External lighting sources should have luminous efficacies as per the table given below

Light Source Minimum allowable luminous efficacy (lm/W) CFLs (compact fluorescent lamps) 50 LEDs (light emitting diodes) 50 Fluorescent Lamps 75 Metal Halide Lamps 75 High Pressure Sodium Vapour Lamps 90

• *Ballasts – All the ballasts installed (including those integrated in CFLs) should be electronic or low loss copper ballasts • *Integration with Renewable Energy Sources – 15% of the total external lighting load or load of 25% (in numbers) of the total external lighting fixtures whichever is higher should be met from renewable energy sources (solar, wind, biomass, fuelcells and so on). “ *are mandatory criteria

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4.3 Guidance Notes

4.3.1 Efficiency in Artificial Lighting Scheme Any lighting scheme interior or exterior can be called an efficient scheme when it provides the required illuminance level for the application it has been designed while utilizing least amount of energy.

Guidance notes for achieving efficiency in the lighting scheme for three categories which are External Lighting, Internal Lighting for Commercial Buildings, and Internal Lighting for Residential Buildings have been elaborated below.

4.3.2 External Lighting Energy efficiency in external lighting – External lighting in and around a building is used for lighting pedestrian walks, landscaping, artifacts, parkways & parking, facade lighting, security etc. To achieve the efficiency in external lighting scheme designed for various application following can be practiced –

Use of efficient Lamps –Depending upon the kind of application, the following lamp types can be used in external lighting scheme to improve the efficiency –

High Pressure Sodium Vapour Lamps (HPSV) High Pressure Sodium vapor lamp is a gas discharge lamp which uses sodium in an excited state to produce light. The efficacy of HPSV varies from 50 140 lumens/watt and lamp life is around 16000 24000 hrs. The color rendering index of these lamps is quite low. These lamps can be primarily used for applications where lighting from a height around 5m is desired such as for the drive ways in a campus or car parking etc.

Metal Halide Lamps (MH) Metal halide lamps are similar in construction and appearance to mercury vapor lamps. The addition of metal halide gases to mercury gas within the lamp results in higher light output, more lumens per watt (50110 lumen/watt) and a higher color rendition index than from mercury gas alone. Metal halide lamps have shorter lifetimes (5,000–20,000 hours) compared to both mercury vapor and highpressure sodium lamps. Metal halide lamps in external lighting are used when better color rendition is required such as facade lighting etc.

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Fluorescent Lamps Fluorescent lamp is a low–pressure mercury electric discharge lamp with a glass tube filled with a mixture of argon gas and mercury vapour at low pressure. When current flows through the ionized gas between the electrodes, it emits ultraviolet (UV) radiation from the mercury arc which is then converted to visible light by a fluorescent coating on the inside of the tube. Fluorescent lamps are usually available in various colors i.e. warm white, normal white, cool white etc. Fluorescent lamp efficacy is around 40100 lumen/watt and the average life of the lamp varies from 10000 – 24000 hrs. The color rendering of the fluorescent lamps is very good.

Compact Fluorescent lamps (CFL) Compact fluorescent lamps are fluorescent lamps which are small in size, come in both types ballast integrated and nonintegrated. Life of CFL lamps is almost 9 to 10 times to that of an incandescent lamp. CFLs can be extensively used in landscape lighting, security lighting fixtures, bollard lighting etc.

Light emitting diode (LED) Lamps The LEDs are semiconductor lighting sources. When a diode is forward biased (switched on), electrons are able to recombine with holes within the device, releasing energy in the form of photons. LEDs consume very less power and have a very long life (5000070000 hrs) as they are shock and vibration proof. LEDs because of their very small size can be used for variety of lighting application in landscaping.

Table 4.1: Lamps and control gears used in outdoor lighting should be selected based on the minimum efficacy values given in the table below Light Source Minimum allowable luminous efficacy (lm/W) CFLs (compact fluorescent lamps) 50 LEDs (light emitting diodes) 50 Fluorescent Lamps 75 Metal Halide Lamps 75 High Pressure Sodium Vapour Lamps 90

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The exterior lighting power for the applications as mentioned in the table given below as per ECBC 2007 should be calculated and it should be in the limit of recommended values in the table –

Table 4.2: Exterior Lighting Power Densities Exterior Lighting Applications Power Limits Building entrance (with canopy) 13W/m 2 (1.3W/ft 2) of canopied area Building entrance (without canopy) 90W/lin m (30 W/lin ft) of door width Building exit 60W/lin m (20 W/lin ft) of door width Building Facades 2W/m 2 (0.2W/ft 2) of vertical facade area

Use of lighting controls Lighting controls such as timer controls, astronomical switches can be integrated with the exterior lighting fixtures in order to save energy when daylight is available outside.

These controls can be programmed to incorporate the seasonal time variation in sun rise and sunset.

Integration with renewable energy sources Renewable energy, largely solar, has got a great potential of saving energy when integrated with the exterior lighting scheme.

Solar outdoor area lighting system operates by using the light energy available from the sun to provide lighting during nighttime. The Solar PV outdoor lighting is a reliable and an efficient standalone system. It consists of a Solar PV module, a Battery & a Luminaire with very high efficient electronics all mounted onto a pole with necessary hardware & cables. Solar based outdoor lighting can be used for various lighting applications such as parking lots, landscape lighting, driveways etc.

It is desirable that solar lights should be located on the south side of the building in order to receive solar radiation through out the day for the entire year.

Care should be taken while selecting Solar PV module location with respect to a building. Solar PV module should not fall in the shadow zone of the building. In Bangalore shadow zone of a building on south side is up to an angle of 30 0 from the top point of the building as shown in the figure below 61 Guidelines for Energy Efficiency in Artificial lighting

4.3.3 Internal Lighting for New Commercial buildings

Efficiency of an internal lighting scheme depends on the following parameters • Interior lighting power density • Lighting design • Efficient lighting equipment e.g. lamps, luminaries and control gears • Use of appropriate lighting controls • Explore possibilities of daylight integration • Ensure effective maintenance • In addition to above the following parameters are also critical o Reflectance of various room surfaces o Glare reduction o Uniform light distribution

Lighting Design Lighting systems and equipment shall comply with the provisions of Energy conservation building Code, 2007 as outlined below Lighting requirements are applicable to following • Interior spaces of buildings, 62 Guidelines for Energy Efficiency in Artificial lighting

• Exterior building features, including facades, illuminated roofs, architectural features, entrances, exits, loading docks, and illuminated canopies, and, Exterior building grounds lighting that is provided through the building's electrical service.

Exceptions The following lighting equipment and applications shall not be considered when determining the interior lighting power allowance, nor shall the wattage for such lighting be included in the installed interior lighting power. However, any such lighting shall not be exempt unless it is an addition to general lighting and is controlled by an independent control device. • Display or accent lighting that is an essential element for the function performed in galleries, museums, and monuments, • Lighting that is integral to equipment or instrumentation and is installed by its manufacturer, • Lighting specifically designed for medical or dental procedures and lighting integral to medical equipment, • Lighting integral to food warming and food preparation equipment, • Lighting for plant growth or maintenance, • Lighting in spaces specifically designed for use by the visually impaired, • Lighting in retail display windows, provided the display area is enclosed by ceiling height partitions, • Lighting in interior spaces that have been specifically designated as a registered interior historic landmark, • Lighting that is an integral part of advertising or directional signage, • Exit signs, • Lighting that is for sale or lighting educational demonstration systems, • lighting for theatrical purposes, including performance, stage, and film or video production • Athletic playing areas with permanent facilities for television broadcasting.

Installed Interior Lighting Power The installed interior lighting power should be calculated for all power used by the luminaires, including lamps, ballasts, current regulators, and control devices. If two or more independently operating lighting systems in a space are controlled to prevent simultaneous user operation, the installed interior lighting power shall be based solely on the lighting system with the highest power.

Interior Lighting Power and Design The installed interior lighting power for a building shall not exceed the interior lighting power allowance determined in accordance with the given below two methods. ECBC 2007 recommended value for lighting power density thus calculated by these methods for various spaces is given in Table 4.3 and 4.4.

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Building Area Method Determination of interior lighting power allowance (watts) by the building area method shall be in accordance with the following: • Determine the allowed lighting power density from Table 4.3 for each appropriate building area type. • Calculate the gross lighted floor area for each building area type. • The interior lighting power allowance is the sum of the products of the gross lighted floor area of each building area times the allowed lighting power density for that building area types.

Space Function Method Determination of interior lighting power allowance (watts) by the space function method shall be in accordance with the following: a. Determine the appropriate building type as per the proposed use and the allowed lighting power density. b. For each space enclosed by partitions 80% or greater than ceiling height, determine the gross interior floor area by measuring to the center of the partition wall. Include the floor area of balconies or other projections. Retail spaces do not have to comply with the 80% partition height requirements. c. The interior lighting power allowance is the sum of the lighting power allowances for all spaces. The lighting power allowance for a space is the product of the gross lighted floor area of the space times the allowed lighting power density for that space.

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Table 4.3: Interior Lighting Power Building Area Method Building Area Type LPD (W/m 2) Building Area Type LPD (W/m 2) Automotive Facility 9.7 Multifamily Residential 7.5 Convention Center 12.9 Museum 11.8 Dining: Bar Lounge/Leisure 14.0 Office 10.8 Dining: Cafeteria/Fast Food 15.1 Parking Garage 3.2 Dining: Family 17.2 Performing Arts Theater 17.2 Dormitory/Hostel 10.8 Police/Fire Station 10.8 Gymnasium 11.8 Post Office/Town Hall/ 11.8 HealthcareClinic 10.8 Religious Building 14.0 Hospital/Health Care 12.9 Retail/Mall 16.1 Hotel 10.8 School/University 12.9 Library 14.0 Sports Arena 11.8 Manufacturing Facility 14.0 Transportation 10.8 Motel 10.8 Warehouse 8.6 Motion Picture Theater 12.9 Workshop 15.1

In cases where both a general building area type and a specific building area type are listed, the specific building area type shall apply.

Table 4.4: Interior Lighting Power – Space Function Method Space Function LPD (W/m 2) Space Function LPD (W/m 2) Officeenclosed 11.8 Library Officeopen plan 11.8 Card File & Cataloging 11.8

Conference/Meeting/Multipurpose 14.0 Stacks 18.3

Classroom/Lecture/Training 15.1 Reading Area 12.9 Lobby 14.0 Hospital For Hotel 11.8 Emergency 29.1 For Performing Arts Theater 35.5 Recovery 8.6 For Motion Picture Theater 11.8 Nurse Station 10.8 Audience/Seating Area 9.7 Exam Treatment 16.1 For Gymnasium 4.3 Pharmacy 12.9 Patient Room 7.5

For Convention Center 7.5 Operating Room 23.7 65 Guidelines for Energy Efficiency in Artificial lighting

Luminaire Wattage Luminaire wattage incorporated into the installed interior lighting power shall be determined in accordance with the following: a. The wattage of incandescent luminaires with medium base sockets and not containing permanently installed ballasts shall be the maximum labeled wattage of the luminaires. b. The wattage of luminaires containing permanently installed ballasts shall be the operating input wattage of the specified lamp/ballast combination based on values from manufacturers’ catalogs or values from independent testing laboratory reports. c. The wattage of all other miscellaneous luminaire types not described in (a) or (b) shall be the specified wattage of the luminaires. d. The wattage of lighting track, plugin busway, and flexiblelighting systems that allow the addition and/or relocation of luminaires without altering the wiring of the system shall be the larger of the specified wattage of the luminaires included in the system or 135 W/m (45 W/ft). Systems with integral overload protection, such as fuses or circuit breakers, shall be rated at 100% of the maximum rated load of the limiting device.

Luminaire efficiency The efficiency of a luminaire is the ratio of luminaire lumen output to the lamp lumen output. Mirror optics of a luminaire and louvers decides the luminaire efficiency along with the improved visual comfort and glare control. Lighting simulation tools can be used to choose which luminaire will suit best the required application by analysing the lighting distribution and glare index.

Efficient luminaire also plays an important role for energy conservation in lighting. The choice of a luminaire should be such that it is efficient not only initially but also throughout its life. Following luminaries are recommended by the NBC 2005 for different locations • For offices semidirect type of luminaries are recommended so that both the work plane illumination and surround luminance can be effectively enhanced. • For corridors and staircases direct type of luminaries with wide spread of light distribution are recommended. • In residential buildings, bare fluorescent tubes are recommended. Wherever the incandescent lamps are employed, they should be provided with white enamelled conical reflectors at an inclination of about 45°from vertical.

Ballasts All discharge lamps, including fluorescents, require ballast for proper operation. Typical ballast losses are taken as approximately 15% of the lamp wattage. It is important to include calculation of ballast losses when comparing consumption and savings of different kinds of lamps.

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New electronic or solid state ballasts, now available in market, save approximately 20— 30% in energy consumption over standard ballasts. Electronic ballasts usually change the frequency of the power from the standard mains (e.g., 50 Hz in India) frequency to 20,000 Hz or higher, substantially eliminating the stroboscopic effect of flicker associated with fluorescent lighting. In addition, because more gas remains ionized in the arc stream, the lamps actually operate at about 9% higher efficiency above approximately 10 kHz. Lamp efficiency increases sharply at about 10 kHz and continues to improve until approximately 20 kHz. Because of the higher efficiency of the ballast itself and the improvement of lamp efficiency by operating at a higher frequency, electronic ballasts offer higher system efficiency.

High efficacy Lamps Lamp efficacy, in an interior lighting scheme, plays a very crucial role. A lighting scheme which utilizes lamps with lower efficacies will result in increased number of lamps and hence increase the LPD (lighting power density) of a space. The increased LPD will not only increase the lighting power consumption but also indirectly increase the heating load on the HVAC equipment and further add to energy consumption. The reduction in energy consumption is possible with proper choice of lighting fixtures and the lamp types. Lighting output and wattage should be seen before choosing the lights.

Given below are examples of high efficacy lamps currently available in market

T5 lamps - These are fluorescent lamps with a diameter of 16 mm, which is 40% less than the diameter of existing slim fluorescent lamps. They are designed for higher efficacy and system miniaturization. The life span of T5 lamps is also Slim fluorescent lamps (T12) very long, around 18 000 hours as compared to 8000 hours T-8 of standard fluorescent lamps.

T-5

Bureau of energy efficiency, India in its appliance energy labelling program has rated various tubular fluorescent lamps, by different manufacturers, on the basis of the energy consumption and light output. Given below is the table listing out the BEE rated TFL lamps

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Table 4.5: BEE (bureau of energy efficiency) rated TFL lamps S.No Product Brand Watt Lamp Type Star Rating 1 TFL OSRAM 36 W HL Tubular Fluorescent Lamp 5 Star 2 TFL OSRAM 36 W HL Tubular Fluorescent Lamp 5 Star 3 TFL OSRAM 36 W HL Tubular Fluorescent Lamp 5 Star 4 TFL PHILIPS 36 W Tubular Fluorescent Lamp 5 Star 5 TFL PHILIPS 36 W Tubular Fluorescent Lamp 5 Star 6 TFL PHILIPS 36 W Tubular Fluorescent Lamp 5 Star 7 TFL WIPRO 36 W Ultralite Tubular Fluorescent Lamp 5 Star 8 TFL WIPRO 36 W Ultralite Tubular Fluorescent Lamp 5 Star 9 TFL WIPRO 36 W Ultralite Tubular Fluorescent Lamp 5 Star 10 TFL CROMPTON 36 W PowerLux Tubular Fluorescent Lamp 5 Star 11 TFL CROMPTON 36 W PowerLux Tubular Fluorescent Lamp 5 Star 12 TFL Samsung 36 W Tubular Fluorescent Lamp 5 Star 13 TFL SURYA 36 W SUPER BRIGHT Tubular Fluorescent Lamp 4 Star 14 TFL GALAXY 36 W SUPER BRIGHT Tubular Fluorescent Lamp 4 Star 15 TFL MYNA 36 W high lumen Tubular Fluorescent Lamp 4 Star 16 TFL SURYA 40 W Tubular Fluorescent Lamp 3 Star 17 TFL SURYA 36 W K SLIMLITE Tubular Fluorescent Lamp 3 Star 18 TFL GALAXY 40 W Tubular Fluorescent Lamp 3 Star 19 TFL GALAXY 36 W SLIMLITE Tubular Fluorescent Lamp 3 Star 20 TFL OSRAM 36 W Tubular Fluorescent Lamp 3 Star 21 TFL OSRAM 40 W OSRAM BASIC PLUS TFL 3 Star 22 TFL OSRAM 40 W Tubular Fluorescent Lamp 3 Star 23 TFL PHILIPS 40 W Tubular Fluorescent Lamp 3 Star 24 TFL PHILIPS 36 W Tubular Fluorescent Lamp 3 Star 25 TFL WIPRO 40 W PREMIUM Tubular Fluorescent Lamp 3 Star 26 TFL WIPRO 36 W SAFELITE Tubular Fluorescent Lamp 3 Star 27 TFL WIPRO 40 W Tubular Fluorescent Lamp 3 Star 28 TFL ANCHOR 40 W Tubular Fluorescent Lamp 3 Star 29 TFL ANCHOR 36 W Tubular Fluorescent Lamp 3 Star 30 TFL CROMPTON 36 W Super Saver Tubular Fluorescent Lamp 3 Star 31 TFL CROMPTON 40 W Brightlux Tubular Fluorescent Lamp 3 Star 32 TFL CROMPTON 40 W Tubular Fluorescent Lamp 3 Star 33 TFL BAJAJ 40 W Cool Day Light Tubular Fluorescent Lamp 3 Star 34 TFL BAJAJ 36 W Tubular Fluorescent Lamp 3 Star 35 TFL HIND 40 W Cool Day Light Tubular Fluorescent Lamp 3 Star 36 TFL HIND 36 W Cool Day Light Tubular Fluorescent Lamp 3 Star 37 TFL MYNA 40 W Tubular Fluorescent Lamp 3 Star 38 TFL MYNA 36 W Tubular Fluorescent Lamp 3 Star 39 TFL GE 36 W GE SLENDER TFL 3 Star 68 Guidelines for Energy Efficiency in Artificial lighting

40 TFL GE 40 W GE Standard TFL 3 Star 41 TFL CEMA 36 W CEMA Energy Saver 3 Star 42 TFL CEMA 40 W CEMA TC 3 3 Star 43 TFL Samsung 40 W Tubular Fluorescent Lamp 3 Star 44 TFL ONIDA 36 W Tubular Fluorescent Lamp 3 Star 45 TFL ONIDA 40 W Tubular Fluorescent Lamp 3 Star 46 TFL ECOLITE 40 W Tubular Fluorescent Lamp 3 Star 47 TFL ECOLITE 36 W Tubular Fluorescent Lamp 3 Star 48 TFL JINDAL 40 W Cool Day Light Tubular Fluorescent Lamp 3 Star 49 TFL PHILIPS 40 W Tubular Fluorescent Lamp 2 Star

Compact Fluorescent lamps CFLs (Compact fluorescent lamps) produce light in the same manner as linear fluorescent lamp. Their tube diameter is usually 5/8 inch (T5) or smaller. CFL power is 555W. Typical CFLs have been presented in figure

Light emitting diodes LEDs are small in size but can be grouped together for higher intensity. The efficacy of a typical residential application LED is approximately 20 lumens per watt though 100 lumens per watt have been created in laboratory conditions. LEDs are better at placing lighting in a single direction than incandescent or fluorescent bulbs. LED strip lights can be installed under counters, in hallways, and in staircases; concentrated arrays can be used for room lighting. Waterproof, outdoor fixtures are also available. Some manufacturers consider applications such as gardens, walkways, and decorative fixtures outside garage doors to be the most cost efficient. LED lights are more rugged and damageresistant than compact fluorescents and incandescent bulbs. LED lights don't flicker. They are very heat sensitive; excessive heat or inappropriate applications dramatically reduce both light output and lifetime. Uses include: • Task and reading lamps • Linear strip lighting (under kitchen cabinets) • Recessed lighting/ceiling cans • Porch/outdoor/landscaping lighting • Art lighting 69 Guidelines for Energy Efficiency in Artificial lighting

• Night lights • Stair and walkway lighting • Pendants and overhead • Retrofit bulbs for lamps LEDs last considerably longer than incandescent or fluorescent lighting. LEDs don't typically burn out like traditional lighting, but rather gradually decrease in light output.

Controls in Daylighted Areas a. There should be use of appropriate controls. And it should be well integrated with internal lighting. Each space enclosed by ceilingheight partitions shall have at least one control device to independently control the general lighting within the space. Each control device shall be activated either manually by an occupant or automatically by sensing an occupant. Refer guidance note for the same. Is capable of reducing the light output of the luminaires in the daylighted areas by at least 50%, and b. Controls only the luminaires located entirely within the daylighted area.

Common types of controls: Lighting controls

Each control device shall a. Control a maximum of 250 m 2 (2,500 ft 2) for a space less than or equal to 1,000 m 2 (10,000 ft 2), and a maximum of 1,000 m 2 (10,000 ft 2) for a space greater than 1,000 m 2 (10,000 ft 2). b. Be capable of overriding the shutoff control required in (a) for no more than 2 hours, and c. Be readily accessible and located so the occupant can see the control.

Exceptions The required control device may be remotely installed if required for reasons of safety or security. A remotely located device shall have a pilot light indicator as part of or next to the control device and shall be clearly labeled to identify the controlled lighting.

Timers These represent the most basic type of automation, and are very popular for outdoor applications. Timers can be simple (responding to one setting all year round) or sophisticated enough to contain several settings that go into effect over time.

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Occupancy sensors These devices – also known as ‘motion detectors’ – turn lights off and on in response to human presence. Once sensitivity and coverage area is established, sensors are selected from two predominant technology types.

Passive infrared sensors These detect the motion or heat between vertical and horizontal detection zones. This technology requires a direct line of sight and is more sensitive to lateral motion, but it requires layer motion as distance from the sensor increases. The coverage pattern and field of view can also be precisely controlled. It typically finds its best application in smaller spaces with a direct line of sight, such as restrooms.

Ultrasonic sensors These detect movement by sensing disturbances in highfrequency ultrasonic patterns. Because this technology emits ultrasonic waves that are reflected around the room surfaces, it does not require a direct line of sight. It is more sensitive to motion towards and away from the sensor and its sensitivity decreases relative to its distances from the sensor. It also does not have a definable coverage pattern or field of view. These characteristics make it suitable for use in layerenclosed areas that may have cabinets, shelving, partitions, or other obstructions. If necessary, these technologies can also be combined into one product to improve detection and reduce the likelihood of triggering a false on or off mode.

Photocells These measure the amount of natural light available and suitable for both indoor and outdoor applications. When available light falls below a specified level, a control unit switches the lights on (or adjusts a driver to provide more light). Photocells can be programmed so that lights do not flip on and off on partially cloudy days.

Case Study – Methodology to design an efficient lighting scheme for a new building

In order to arrive at the optimum combination, the following options have been analysed 1. Case –1 Analyse the proposed case (given by architect) 2. Case 2 Modification in the proposed case to achieve visual comfort if not met 3. Case–3 Select Luminaire with twin fitting of 28 W T5 lamp with higher luminaire efficiency 4. Case4: Use efficient low glare fixture with twin 36W CFL lamp mirror optic luminaries/lamps/ballasts

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Assumptions The following assumptions have been taken for the analysis: Project maintenance factor = 0.8 Reflectance of Ceiling = 0.7 Walls = 0.5 Floor = 0.3 The existing lighting design incorporates luminaire which is Philips TMC501 with 40W fluorescent tube lights (2450 lumen is the output of standard T12 40W tube light)

Observation: • In order to achieve the desired illuminance levels as recommended by NBC, the number of fixtures has to be optimised so that the lighting power density should not exceed the ECBC 2007 guideline. • The desired lux levels and uniformity can be achieved for lower lighting power density values with a combination luminaires with better mirror optics and high efficiency triphosphor tube lights and CFLs.

Case 1 analysis: Lighting scheme with monophosphor lamp

The general lighting scheme in case 1 uses the luminaire with following specifications 1. Manufacturer : Philips 2. Luminaire Type : TMC501 3. Lamp Type : 1x40 W TLD 4. Lumen Output : 2450lm/lamp 5. Ballast power loss : 15W 6. Total power consumption of lamp : 55W/lamp

Observation: a. It has been observed from the table 1 below that the average lighting levels of the office room is 84 and it is not conforming the recommended NBC2005 standard. b. The energy efficiency point of view, the overall LPD achieved for the office room is 3.85 W/m2 which is below the ECBC 2007 recommended value. c. Uniformity ratio achieved in this case is 0.49

Table 4.6: Case 1 Illumination level and LPD of the office room Average Uniformity NBC ECBC No. of LPD Floor Area illumination ratio illumination recommended fixture (W/m 2) level (lux) (Min/Avg) level (lux) LPD

(Office)Staff Ground 8 84 3.85 0.49 300500 11.8 floor for seating 72 Guidelines for Energy Efficiency in Artificial lighting

Figure 4.1: Rendered image and Isolux diagram of the office room

Case 2 analysis: Modification in the proposed case to achieve visual comfort if not met

The lighting scheme consists of the same monophosphor lamp but the number of fixtures has been increased in order to meet the illuminance levels as recommended by NBC. Given below is the luminaire specification 1. Manufacturer : Philips 2. Luminaire Type : TMC501 3. Lamp Type : 1x40 W TLD 4. Lumen Output : 2450lm/lamp 5. Ballast power loss : 15W 6. Total power consumption of lamp : 55W/lamp

Observation: 1. It has been observed from the table 2 given below that the average lighting levels of the office room is 403 and it is not conforming the recommended NBC2005 standard. 2. The energy efficiency point of view, the overall LPD achieved for the office room is 13.42 W/m2 which is higher than the ECBC 2007 recommended value. 3. Uniformity ratio achieved in this case is 0.74

Table 4.7: Case 2 Illumination level and LPD of the office room Average Uniformity NBC ECBC No. of Floor Area illumination LPD(W/m 2) ratio illumination recommended fixture level (lux) (Min/Avg) level (lux) LPD (Office) Staff Ground 21 403 13.42 0.74 300500 11.8 floor for seating

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Figure 4.2: Rendered image and Isolux diagram of the office room

Case 3 analysis: Select Luminaire with twin fitting of 28 W T5 lamp with higher luminaire efficiency

The general lighting schemes in this case has been designed considering the 2 x 28W advanced recessed luminaries with D8 Microoptics, with excellent glare control. Given below is the luminaire specification • Manufacturer :Philips • Luminaire Type :TBS 814 • Lamp Type :2x28 W TLD • Lumen Output :2900lm/lamp • Ballast power loss :2W • Total power consumption of lamp :30W/lamp

Observation: a. It has been observed from the table 3 given below that the average lighting levels of the office room is 412 and it is conforming to the recommended NBC2005 standard. b. The overall LPD achieved for the office room is 6.7 which is below the ECBC 2007 recommended value. c. Uniformity ratio achieved in this case is 0.48, same as the previous case.

Table 4.8: Case 3 Illumination level and LPD of the office room Average Uniformity NBC ECBC No. of LPD Floor Area illumination ratio illumination recommen fixture (W/m 2) level (lux) (Min/Avg) level (lux) ded LPD (Office) Ground 18 412 6.7 0.48 300500 11.8 floor Staff for seating

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Figure 4.3: Isolux diagram of the office room

Case 4 analysis: Use efficient low glare fixture with twin 36W CFL lamp mirror optic luminaries/lamps/ballasts

The general lighting schemes in this case has been designed considering luminaire with 2 x 36W CFL, highly efficient with wide paralite P5 louvres to achieve low glare. Electronic ballast with nominal power factor of 0.90 0.95 has been considered. The luminaire specifications are given below • Manufacturer : Wipro • Luminaire Type : WIP48236 • Lamp Type : 2x36 W CFL • Lumen Output : 2900lm/lamp • Ballast power loss : 4W • Total power consumption of lamp : 40W/lamp

Observation: a. It has been observed from the table 4 given below that the average lighting levels of the office room is 464 and it is conforming to the recommended NBC2005 standard. b. The overall LPD achieved for the office room is 11.8 which is exactly the same as recommended in ECBC 2007. c. Uniformity ratio achieved in this case is 0.53, which seems to be better than other.

Table 4.9: Case 4 Illumination level and LPD of the office room Average Uniformity NBC ECBC No. of LPD Floor Area illumination ratio illumination recommended fixture (W/m 2) level (lux) (Min/Avg) level (lux) LPD (Office) Ground 20 464 11.8 0.53 300500 11.8 floor Staff for seating

75 Guidelines for Energy Efficiency in Artificial lighting

Figure 4.4: Isolux diagram of the office room

Summary of analysis

Table 4.10: Summary of analysis and recommendation of the artificial lighting Typical Average Illumination level achieved Lighting power density achieved (W/m 2) Area (lux) ECBC Illumination 2007 Case1 Case2 Case3 Case4 level (lux) as Case1 Case2 Case3 Case4 recommen per NBC 2005 ded LPD Office room 84 403 412 464 300500 3.85 13.42 6.7 11.8 11.8

Life cycle cost analysis

LCCA is different from the payback method of economic analysis since payback method focuses only on how quickly the initial investment can be recovered and does not show long term economic performance or profitability of retrofit measures. Payback period ignores all costs and savings occur after the pay back period is reached and the system life where measure to be implemented. Moreover, the simple payback method, which is commonly used, ignores the timevalue of money when comparing the future stream of savings against the initial investment cost. In calculating the life cycle cost analysis 15 years are taken as total life of the luminaries. From the life cycle graphs it is clearly seen the total life cycle cost will significantly decrease at the end of 15 years time and hence better payback. 76 Guidelines for Energy Efficiency in Artificial lighting

Figure 4.5: Life cycle cost analysis of different Lighting schemes

Table 4.11: Life cycle cost comparison Outputs Units Case: 2 Case: 3 Case: 4 Lamp wattage KW 1.1 0.7 1.8 Initial cost Rs 65700 85860 29000 Operating hr/d Hrs/day 8 8 8 Energy consumption/yr KWh/yr 2640 1680 4320 Energy rate Rs/kWh 5 5 5 Maintenance cost Rs 1314 1717.2 580 Energy cost Rs/yr 13200 8400 21600 LCC Rs 232175 218655 303081 Note : Case 1 in the table indicates improved lighting analysis

Recommendation It is clear from the Figure 5, that initial cost for case 3 is slightly high in but at the end of the cycle time, it gives better saving. Hence case 3 option i.e. TBS 814/228 D8 HF is the best option among the other alternatives.

Conclusion The main findings of the study are as follows:

• With proposed design i.e. the case 1, the illumination levels are very low. No doubt lighting load will be less but this may cause visual discomfort and not advisable. 77 Guidelines for Energy Efficiency in Artificial lighting

• Inefficient lighting luminaire (along with lamp) may produce required illumination but at a higher lighting power density value which will increase the lighting energy consumption, • Use of efficient lighting fixtures along with efficient lamps will not only produce the required illumination but also provide check on the increasing energy demand. Therefore it is highly recommended to use such fixtures in place of inefficient ones in existing lighting schemes. • Using efficient lighting equipment will definitely increase the initial or first cost but the total cost or the life cycle cost, which includes both the first cost and recurring cost (energy & maintenance cost) of such lighting schemes, if calculated for a period of fifteen years, comes out to be less than the LCC of a system which is designed with cheaper and inefficient equipment to produce same illumination.

4.3.4 Retrofitting options in Existing commercial buildings

Given below is the methodology to check and improve the efficiency of the existing lighting scheme in commercial buildings 1. Interior Lighting Power Density – Interior lighting power density for the existing lighting scheme should be calculated as per the methods explained above. If the LPD values are not in the limit of the ECBC recommended values then to reduce it to the recommended values following can be practiced – a. Replacement of Lamps – Lamps in the existing lighting scheme can be replaced by the one having higher efficacies e.g. 40w TLD lamp can be replaced by T5, higher BEE star rated lamps or the Incandescent lamps can be replaced by the CFL or LED lamps etc. b. Replacement of Ballasts – Conventional magnetic ballasts can be replaced by more efficient electronic ballasts c. Replacement of Luminaires – Luminaires with better mirror optics which enhances the light distribution and also the light output of a luminaire can be opted. 2. Lighting Controls – Automatic lighting controls as recommended by ECBC 2007, mentioned above, can be integrated in the lighting scheme to reduce the wastage of lighting energy as and when not required. Daylighting controls can help in dimming or switching off the luminaire in the daylighted zone during the availability of daylight.

4.3.5 Internal Lighting for New Residential buildings

Efficiency of interior lighting scheme in a residential building depends on the following parameters 78 Guidelines for Energy Efficiency in Artificial lighting

1. Lighting power density – Lighting power density in a residential building should comply with ECBC recommended value given above in Table 3, 4. Following can be applied in order to keep LPD in the recommended value – a. Lamp Selection – Lamps with high efficacies, examples given in the above part, should be used for general lighting. b. Ballasts – Electronic ballasts or low loss copper ballast can result in higher system efficacies and reduce losses. c. Luminaire efficiency – The decorative luminaires used in the residential building in general have translucent surfaces which reduces the luminaire efficiency of a fixture and results in installing more number of fixture for same illuminance levels. While selecting the lamp, fixtures having high translucency should be selected. 2. Reflectance of surfaces – Spaces which have finishes dark in color leads to install more number of lamps for similar illuminance levels. Ceiling, wall and other surfaces should be of light color so as to achieve better light distribution and illuminance levels. 3. Lighting Design – Lighting design in a residential area plays key role in governing the efficiency of the design. Following factor should be kept in mind while designing lighting scheme for residential building • Lamps with suitable wattage need to be selected for different spaces depending upon the space geometry. It is always desirable to have multiple fixtures instead of providing single fixture of higher wattage. • Lamp placement should be such that – o One can achieve better light distribution in space o One can utilize the natural light available in daytime from the fenestration and don’t have to switch on lamps unnecessarily

Case Study The case study described below for a 3BHK apartment shows the importance of all the above mentioned parameters such as lamp selection, control gear selection, placement of fixtures etc. in making a lighting scheme efficient one –

Step 1 - Calculation of Lighting Power density For each of the space first of all the area should be calculated. Area of each space should be multiplied by 7.5 (the recommended LPD value by ECBC for residences) to get the upper limit of lighting power density value as shown in the figure below 79 Guidelines for Energy Efficiency in Artificial lighting

7.5 x 22 = 1 65 7.5 x 16 = 120

7.5 x 13 = 97.5 7.5 x 28 = 210

7.5 x 52 = 390

Step 2 – Lighting Design and lamp selection Considering the Living/Dining area as an example for lighting design, first of all location and source selection plays an important role in design. On longer facades we can install the linear lighting sources while on the ceiling recessed point sources can be installed. After freezing the design, in terms of location and type of sources, we can advance to the lamp and gear selection process. Considering the Option 1, as shown in the figure, the linear lighting sources are 40 W T12 FTLs with magnetic ballasts and point sources are 60W incandescent lamps. The lighting load in Option 1 for the space comes out to be 400W which is higher then the upper limit value of 390 W for the space; hence the lighting scheme for the option 1 is an inefficient one.

Connected load including ballast – 4 x (40 + 15) = 220W 3 x 60 = 180W Total = 400W Upper limit = 390W Hence inefficient design

Option 1 80 Guidelines for Energy Efficiency in Artificial lighting

Now, for Option 2, as shown in the figure, the linear lighting sources are 28 W T5 FTLs with electronic ballasts and point sources are 15 W CFLs with electronic ballast. The lighting load in Option 2 for the space comes out to be 165 W only which is quite low than the upper limit value of 390 W; hence the lighting scheme in Option 2 is an efficient one.

Connected load including ballast – 4 x (28 + 2) = 120W 3 x 15 = 45W Total = 165W Upper limit = 390W Hence efficient design

Option 2

4.3.6 Retrofitting options in Existing residential buildings

Given below is the methodology to check and improve the efficiency of the existing lighting scheme in residential buildings

1. Interior Lighting Power Density – Interior lighting power density for the existing lighting scheme should be calculated as per the methods explained above. If the LPD values are not in the limit of the ECBC recommended values then to reduce it to the recommended values following can be practiced – a. Replacement of Lamps – Lamps in the existing lighting scheme can be replaced by the one having higher efficacies e.g. 40w TLD lamp can be replaced by T5, higher BEE star rated lamps or the Incandescent lamps can be replaced by the CFL or LED lamps etc. b. Replacement of Ballasts – Conventional magnetic ballasts can be replaced by more efficient electronic ballasts c. Replacement of Luminaires – Decorative fixtures which have surfaces with high translucency can be selected in order to reduce the wattage of lamp for same lumen output. 81 Guidelines for Energy Efficiency in Artificial lighting

2. Lighting Design – Existing lighting design needs to be studied on factors mentioned below and if possible should be modified appropriately as given in the case study above a. Light distribution in space b. Utilization of daylight during day time from windows c. Placement of lighting fixtures

82 Guidelines for Energy Efficiency in Artificial lighting

Lighting Manufacturer contact details

SN Name Address Contact details 1 Asian Electronics 1799/430, 490, Srigandakavala, Ph: 080 – 3488974 Magadi Main Road, Sunradan Kahle Vishsaneedam , Banglore560091 2 Bajaj Electricals Bajaj Bhavan, Ph: 0802238984 NO 16, Residency Rod Fax: 0802214878 Bangalore 560025 3 CERCO Lighting CENTRAL ELECTRIC & RADIO CO. Ph: 0222208 1125 / 2208 1183 1416, Lohar Chawl, Fax: 0222200 1693 Mumbai 400 002. (India) 4 Decon Lighting 5, Lok Nayak Bhawan, Khan Market Ph: 01124617795, 24692863 New Delhi 110003 Fax: 911124633004 5 GE Lighting Plot No. 42/1 & 45/14 Ph +918028528355 / 375 to 380 Electronic City Phase II Fax: +918028528366 Bangalore – 560100 6 Halonix Lighting No.6, "Legacy" 1st Floor Ph: 08030527032 Convent Road, Richmond Town Bangalore 560025 7 Havells India Limited 6th Floor, Emerald, Madras Bank Road Ph: 08039882100, 08030515801, (Lavelle Road) Bangalore 560001 08030515802/3/4 Fax: 08022112663 8 Lucifer Lights Ltd. 15, Shree Krishna CHS, Ph. 02026455525, 26455526 Opp. Prince Mangal Karyalya Mobile 93255 10557, 92700 52758 Near Apsara Theatre Pune Maharashtra India 411 037 9 OSRAM India Pvt Ltd. Unit No# 301 303, Ph: 08025210919, MADISON ,4th Floor, Fax: 08025210920 Airport Road (1/3 Kodihalli Main Road) Bangalore 560008 10 Philips Electronics India The Estate, 4th floor (North Wing) Limited (Next to Manipal Centre) 121, Dickenson Road Bangalore 560042, India. 11 Surya Roshni No.98, 1st Floor Main Ph: 08026751008 / 26751004 / New timber Yard Layout 32973898 Mysore Road Bangalore 560026 12 Wipro Lighting Doddakannelli, Sarjapur Road, Ph.: 08028440011 Bangalore 560035 Fax: 08028440057

GUIDELINE 5: Energy efficient Air Conditioning system design for buildings

5.1 Guideline: Achieve inside design condition in a conditioned space as recommended by National Building Code with energy efficient HVAC design by following mandatory requirements as recommended in Energy Conservation Building Code (ECBC) of India.

5.1.1 Mandatory clause to be included in the Revised Bye Laws

The inside design conditions of a conditioned space should conform to as recommended in the National Building Code 2005. The outside design conditions shall be in accordance with the conditions specified in National Building Code 2005.

5.2 Technical Notes

Technical guidance to achieve the recommendations

5.2.1 Air conditioning Air conditioning is the process of treating air so as to control simultaneously its temperature, humidity, purity, distribution and air movement and pressure to meet the requirements of the conditioned space.

The objective of installing ventilation and air conditioning in a building is to provide conditions to people that they can live and work in comfort, safely and efficiently.

In common perspective air conditioning is generally associated to cooling & dehumidification during summer & monsoon when heat is extracted from the space.

Following are the guidelines to achieve energy efficiency in air conditioning system design It should be noted that first step to reduce energy consumption in an air conditioning system is to reduce dependence on air conditioning. Therefore it is suggested to delineate spaces that need air conditioning and that do not need air conditioning. Reduction of air conditioned area can reduce both AC loads and energy consumed. Areas such as lobbies, corridors, and atrium need not be air conditioned in the Moderate climate of Bangalore. Next step is to optimise cooling load by judiciously selecting inside design conditions, outdoor design 84 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

conditions, ventilation rate and precooling of fresh air required for maintaining good indoor quality by properly heat or energy recovery from cooled exhaust air. Finally it’s the efficient equipment selection coupled with adequate computer operated controls which optimises the energy performance of the air conditioning systems.

5.2.2 Guidelines on optimization of cooling load estimation

1. Inside design condition: A thermal comfort condition in an air conditioned space is defined by the desired dry bulb temperature and Relative Humidity. National Building Code of India specifies the inside design conditions in air conditioned spaces for some of the building applications which are given in Table 5.1 below.

Table 5.1: Inside design conditions for air conditioned spaces in the Bangalore city

S. No. Category Inside Design Conditions

(I) Restaurants DB 23 to 26 C

RH 55 to 60% (ii) Office Buildings DB 23 to 26 C RH 55 to 60% (iii) Radio and Television Studios DB 23 to 26 C RH 45 to 55% (iv) Departmental Stores DB 23 to 26 C RH 50 to 60% (v) Hotel Guest Rooms DB 23 to 26 C RH 50 to 60% (vi) Class Room DB 23 to 26 C RH 50 to 60% (vii) Auditoriums DB 23 to 26 C RH 50 to 60% (viii) Recovery Rooms DB 24 to 26 C RH 45 to 55 % (ix) Patient Rooms DB 24 to 26 C RH 45 to 55 % (x) Operation Theatres DB 17 to 27 C RH 45 to 55 % (xi) Museums and libraries DB 20 to 22 C RH 40 to 55 % (xii) Telephone Terminal Rooms DB 22 to 26 C RH 40 to 50 % * DB: Dry bulb temperature, RH: Relative humidity 85 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

2. Outdoor design conditions: The outdoor design conditions for Bangalore city for cooling load estimation shall be in accordance with the conditions given in National Building Code and reproduced in Table 5.2 below.

Table 5.2: Recommended outdoor design conditions for Bangalore city for cooling load estimation Cooling DB/MCWB Cooling WB/MCDB

0.4 % 1.0 % 2.0 % 0.4 % 1.0 % 2.0 %

DB MCWB DB MCWB DB MCWB WB MCDB WB MCDB WB MCDB

34.7 19.6 34 19.6 33.1 19.2 23.5 28.9 22.9 28.2 22.5 27.7

* DB: Dry bulb temperature, MCWB: Mean coincidental wet bulb temperature, WB: Wet bulb temperature, MCDB: Mean coincidental dry bulb temperature

Values of ambient drybulb and wetbulb temperatures against the various annual percentiles represent the value that is exceeded on average by the indicated percentage of the total number of hours. The 0.4 %, 1.0% and 2.0% values are exceeded on average 35, 88 and 175 hours in a year.

For normal comfort jobs values in 1% column should be used for cooling load estimation.

For critical applications values in 0.4% column should be used for cooling load estimation.

3. Minimum outside fresh air or ventilation rate The fresh air supply is required to maintain an acceptable nonodorous atmosphere (by diluting body odorous and tobacco smoke) and to dilute the carbon dioxide exhaled. The quantity may be added per person and is related to the occupant density and activity within the air conditioned space.

Minimum ventilation rate which is to be maintained in air conditioned spaces in Bangalore city shall conform to the minimum ventilation rates recommended in breathing zone in ASHRAE Standard 62.1, 2007 (Ventilation for acceptable indoor quality).

The minimum ventilation rates for office building spaces are reproduced in table5.3 below.

Table 5.3: Minimum ventilation rates in breathing zone (This table is not valid in isolation; it must be used in conjunction with the accompanying notes) Occupancy People Outdoor Air Area Outdoor Notes Occupant Combined Outdoor Air Category Rate R P Air Rate R a Density (see Air Rate (see Note 5) Class Note 4) cfm/person L/s cfm/ft 2 L/s #/1000 ft 2 or Cfm/person L/s 86 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

person m2 #/100 m 2 person Office Buildings Office space 5 2.5 0.06 0.3 5 17 8.5 1 Reception 5 2.5 0.06 0.3 30 7 3.5 1 areas Telephone/data 5 2.5 0.06 0.3 60 6 3.0 1 entry Main entry 5 2.5 0.06 0.3 10 11 5.5 1 lobbies

4. Pre cooling of fresh air required for maintaining good IAQ The outdoor fresh air is necessary in an air conditioned environment to maintain good indoor quality but since this air is at higher temperature as compared to return air temperature from conditioned space, it adds to the cooling demand of the space. Therefore in order to maximize benefit of outdoor fresh air and minimize its impact on cooling load and subsequently on energy use in air conditioned system, pre cooling of outdoor fresh air before it gets mixed up with return air from conditioned space which is at room temperature is recommended. The precooling of outdoor fresh air can be carried out with the help of Energy Recovery Wheel (ERV).

Outside Air Energy recovery Damper wheel

Supply Air

Outdoor Air

Return Air Air Exhaust Air

EA and OA Filters

Energy Recovery Wheel In energy recovery wheel or enthalpy wheel (see Figure below), energy recovery is provided by drawing outside air across half of the enthalpy wheel and drawing exhaust air across the other half. Latent heat and sensible heat are transferred from the hotter and moist exhaust air to the colder and dry outside air during winter conditions. Latent heat and sensible heat are transferred from the hotter and moist outside air to the cooler and dry exhaust air during summer conditions. Energy recovery control consists of starting and stopping an exhaust fan, modulating the speed of the exhaust fan, starting and stopping an enthalpy wheel, optionally controlling the speed of the enthalpy wheel and opening and closing a set of bypass dampers. The outdoor dampers are controlled in the normal manner. 87 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Air handling units or treated fresh air systems that have both a design supply air capacity of 5000 cubic feet minute (cfm) or greater and have a minimum outdoor air supply of 70% or greater of the design supply air quantity shall have an energy recovery system with at least 50% recovery effectiveness. Fifty percent energy recovery effectiveness shall mean a change in enthalpy of outdoor air supply equal to 50% of the difference between the outdoor air and return air at design conditions. Provision shall also be made to bypass or control the energy recovery system to permit air economizer operation.

5. Cooling demand It is recommended that for different building typologies in Bangalore the cooling demand or load shall not exceed 500 Sqft /TR.

6. Air conditioning power density It is recommended that the connected electrical load of the entire air conditioning system shall not exceed 7 W/Sqft.

The air conditioning system power density is calculated by dividing the total connected electrical load of the entire air conditioning system in watts by total air conditioned areas in ft 2.

5.2.3 Guidelines on AHU specifications to achieve energy efficiency

Air Handling Units An air handler, or air handling unit (often abbreviated to AHU), is a device used to condition and circulate air as part of a heating, ventilating, and airconditioning (HVAC system.

Components: An air handler is a large metal box containing a blower, heating and/or cooling elements filter racks or chambers, sound attenuators, and dampers. Air handlers usually connect to ductwork that distributes the conditioned air through the building, and returns it to the AHU.

(1) Air system design shall be equipped to operate in 100% outside fresh air mode.

Night purging In daytime occupied buildings which are only occupied in day time, air conditioned systems are kept switched off during nigh and on week ends. That means excessive heat is not removed from spaces during that period. This heat remains in the space and when air conditioned systems are switched on next day in the morning this heat built up need to be removed. That compels air conditioning system to operate at higher load and for longer duration and increases energy consumption. At night when outside temperature drops in Bangalore the cooled air can be used to flush the excessive heat from the spaces during night 88 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

and this is termed as night purging. However, night purging is only possible if more and more outside fresh air is pumped in the spaces during night or early morning. The existing AHUs are designed to provide only required outside fresh air which is generally 20% of the total air quantity circulated by the AHUs. In night purging recirculation of air is unwanted since it would not able to remove excessive heat therefore AHUs shall have provision with the help of sensors, dampers and supply and/or return fans to operate in 100% fresh air mode for nigh purging to eliminate or reduce heat built up during night and week ends.

Free cooling Air-side economizers They can save energy in buildings by using cool outside air as a means of cooling the indoor space. When the enthalpy of the outside air is less than the enthalpy of the re circulated air, conditioning the outside air is more energy efficient than conditioning re circulated air. When the outside air is sufficiently cool, no additional conditioning of it is needed; this portion of the airside economizer control scheme is called free cooling .

Airside economizers can reduce HVAC energy costs in cold and temperate climates while also potentially improving indoor air quality and shall be used in moderate climate of Bangalore wherever applicable.

Air side Economizers should be designed in accordance with ASHRAE 90.1.2007 which is explained below.

Design capacity Air economizer systems shall be capable of modulating outdoor air and return air dampers to provide up to 100% of the design supply air quantity as outdoor air for cooling Control signal Economizer dampers shall be capable of being sequenced with the mechanical cooling equipment and shall not be controlled by only mixed air temperature. However, the use of mixed air temperature limit control shall be permitted for the systems controlled from space temperature e.g., singlezone systems

High-limit shutoff All air economizers shall be capable of automatically reducing outdoor air intake to the design minimum outdoor air quantity when outdoor air intake will no longer reduce cooling energy usage. The highlimit shutoff control types and settings for those controls shall be as recommended in ASHRAE standard 90.1.2007.

(2) AHUs to be equipped to vary the supply air capacity AHUs are sized for the peak load condition which seldom occurs. Most of the time AHUs operate at part load conditions. If operating capacity of the AHUs are not controlled in 89 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

conjunction with the cooling demand that would lead to over cooling which in turn cause both discomfort and energy wastage. The AHUs used in most of the comfort cooling are constant air volume that means the air quantity they circulate is constant and hence fan operates as constant speed. The part load operating capacity of AHUs can be controlled either by increasing the supply air temperature which is possible by varying the chilled water flow in coil with same air quantity or by varying the air quantity but keeping the supply air temperature same. However, it has been observed that the best comfort conditions can be provided if AHUs have provision for both.

It is recommended that AHUs shall have provision to vary supply air quantity in response to the varying cooling demand with a minimum supply air capacity up to 50% of the design supply air capacity. This can be achieved by installing variable frequency drives on constant speed fans fitted in AHUs.

Variable frequency drives are devices used for varying the speed of fans to exactly match the supply air quantity required to provide required cooling in the conditioned space. A VFD consists of an input rectifier (which converts AC to DC) followed by an inverter (that inverts DC to AC) connected through a DC intermediate voltage link and operates in response to the return air temperature.

3. AHU minimum fan efficiency The energy consuming component in AHUs is fan and fan efficiency plays and important role in enhancing over all efficiency of the air conditioning systems. Forward curved, backward curved or radial types of centrifugal fans are generally used in AHUs. For fans less than 6 bhp (break horse power) the fan efficiency shall not be less than 65% and fans 6bhp and larger the fan efficiency shall not be less than 80%.

4. Minimum efficiency of motors 2 pole & 4 pole, 3 phase squirrel cage induction motors are generally used in air conditioning systems. The minimum efficiency of motors shall be in compliance with nominal efficiency of eff1 type mentioned in Table 1 & Table 2 for 2 poles & 4 poles motors in Indian standard IS 12615: 2004 – Energy efficiency induction motors – Three phase squirrel cage (First Revision).

Table5.4: Values of performance characteristic of 2 pole & 4 pole energy efficient induction motors Rated 2pole Motor Nominal 4pole Motor Nominal output Efficiency Efficiency (kW) For eff 1 For eff 1 (%) (%) 0.37 70.2 73 0.55 74 78 0.75 77 82.5 90 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

1.1 82.8 83.8 1.5 84.1 85 2.2 85.6 86.4 3.7 87.5 88.3 5.5 88.6 89.2 7.5 89.5 90.1 9.3 90 90.5 11 90.5 91 15 91.3 91.8 18.5 91.8 92.2 22 92.2 92.6 30 92.9 93.2 37 93.3 93.6 45 93.7 93.9 55 94 94.2 75 94.6 94.7 90 95 95 110 95 95.2 125 95.3 95.5 132 95.3 95.5 160 95.5 95.8

5.2.4 Guidelines for energy efficient Chillers

Chiller is a device that removes heat from a liquid via a vapourcompression or absorption refrigeration cycle. This cooled liquid flows through pipes in a building and passes through coils in air handlers, fancoil units, or other systems, cooling and usually dehumidifying the air in the building. Chillers are of two types; aircooled or watercooled. Aircooled chillers are usually outside and consist of condenser coils cooled by fandriven air. Watercooled chillers are usually inside a building, and heat from these chillers is carried by re circulating water to outdoor cooling towers.

1. Chiller efficiency as per ECBC recommendations (foot note of ASHRAE 90.1.2007 to be included). All cooling equipment shall meet or exceed the minimum efficiency requirements presented in Tables below: Minimum Minimum S No. Equipment Class Test Standard COP IPLV 91 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Unitary Air Cooled Air Conditioner ≥19 and <40 kW ( ≥5.4 3.08 ARI 210/240 1 and <11 tons ) 2 Unitary Air Cooled Air Conditioner ≥40 to <70 kW (≥11 to 3.08 ARI 340/360 3 Unitary Air Cooled Air Conditioner ≥70 kW (≥20 tons) 2.93 2.99 ARI 340/360 Unitary Water Cooled Air Conditioner <19 kW (<5.4 tons) 4.1 ARI 210/240 4

5 Unitary Water Cooled Air Conditioner ≥19 and <40 kW 4.1 ARI 210/240 6 Unitary(≥5.4 and Water <11 Cooledtons ) Air Conditioner ≥<40 kW (≥11 tons ) 3.22 3.02 ARI 210/240 Minimum Minimum S No. Equipment Class Test Standard COP IPLV 1 Air Cooled Chiller <530 kW (<150 tons) 2.9 3.16 ARI 550/5901998 2 Air Cooled Chiller ≥530 kW (≥150 tons) 3.05 3.32 ARI 550/5901998 Centrifugal Water Cooled Chiller < 530 kW (<150 5.8 6.09 ARI 550/5901998 3 tons) Centrifugal Water Cooled Chiller ≥530 and 5.8 6.17 ARI 550/5901998 4 <1050 kW ( ≥150 and <300 tons) Centrifugal Water Cooled Chiller ≥ 1050 kW (≥ 6.3 6.61 ARI 550/5901998 5 300 tons) Reciprocating Compressor, Water Cooled Chiller 4.2 5.05 ARI 550/5901998 6 all sizes 7 Rotary Screw and Scroll Compressor, Water 4.7 5.49 ARI 550/5901998 (<150Cooled tons) Chiller <530 kW Rotary Screw and Scroll Compressor, Water 5.4 6.17 ARI 550/5901998 8 Cooled

Chiller ≥530 and <1050 kW

(≥150 and <300 tons)

Rotary Screw and Scroll Compressor, Water 5.75 6.43 ARI 550/5901998 9 Cooled Chiller ≥ 1050 kW

(≥ 300 tons)

2. Supply chilled water temperature shall not be lower than 44 o F ARI conditions specify a supply chilled water temperature of 44 o F and return at 54 o F or in chilled water line and a temperature drop of 10 o F is recommended. For comfort applications where a 75 o F temperature and 60 % RH is recommended to maintain in spaces, the cooled air is generally supplied at 55 o F and in order to get the supply air at design condition the chilled water temperature in coil is maintained around 44 o F. Recently a new trend has started to design chilled water loop water higher delta T which is more than 10 o F (generally 12 to 14 o F) to save energy in pumping. This trend is also introducing a lower chilled water supply design temperature than 44 o F. The lowering of chilled water adversely affects the 92 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

efficiency of chiller and whatever advantage is gained in saving pumping energy ay be lost in increased chiller energy. Bangalore climate also does not demand a lower chilled water temperature for humidity control. Therefore it is recommended that for water chillers in comfort applications the supply chilled water temperature shall not be lower than 44 o F.

3. Chilled water flow rate shall not exceed 2 gpm/TR The chilled water flow/TR is defined by 24/delta T where delta T is the difference of supply chilled water and return chilled water temperature. In chilled water line the design delta T is 10 o F as per ARI specifications that means chilled water line should be designed for 2.4 gpm (US gallon per minute). High chilled water flow leads to high pumping energy and in order to reduce pumping energy chilled water lines are being designed for high delta T which is more than 10 o F. It is recommended that chilled water line shall be designed for a flow rate of 2 gpm/TR or lower that means the design delta T in chilled water line shall be 12 o F or higher.

4. All unitary systems (split & window unit) shall be BEE 5 Star rated.

BEE standard & labeling program The Objectives of Standards & Labeling Program is to provide the consumer an informed choice about the energy saving, and thereby the cost saving potential of the marketed household and other equipment. This is expected to impact the energy savings in the medium and long run while at the same time it will position domestic industry to compete in such markets where norms for energy efficiency are mandatory.

The scheme was launched in May, 2006 and is currently invoked for equipments/appliances (Frost Free(NoFrost) refrigerator, Tubular Fluorescent Lamps, Room Air Conditioners, Direct Cool Refrigerator, Distribution Transformer, Induction Motors, Pump Sets, Ceiling Fans, LPG, Electric Geysers and Color TV).

Room air conditioners labelling BEE energy labelling is for singlephase split and unitary air conditioners of the vapour compression type to a rated cooling capacity of 11 kW. Star rating The available stars are between of one and a maximum of five shown in one star interval. The star rating is calculated from the star rating band given in table below. The star rating band is a range of energy efficiency ratio (EER) expressed in W/W and that is nothing but the ratio of cooling capacity in watts to energy consumption also in watts.

Table5.5: Star rating band valid from 01 January to 31 December 2012 Star Rating EER (W/W) Min Max 93 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

1 Star * 2.7 2.89 2 Star ** 2.9 3.09 3 Star *** 3.1 3.29 4 Star **** 3.3 3.49 5 Star ***** 3.5

It is recommended that only a BEE five star rated room air conditioners shall be used for air conditioning of spaces.

5.2.5 Guidelines for energy efficient Cooling Tower

Cooling Towers Cooling towers are used to dissipate heat from water cooled refrigeration, air conditioning and industrial process systems. Cooling is achieved by evaporating a small proportion of recirculating water into outdoor air stream. Cooling towers should be installed at a place where free flow of atmospheric air is available.

Range of cooling tower is defined as temperature difference between the entering and leaving water. Approach of the cooling tower is the difference between leaving water temperature and the entering air wet bulb temperature.

1. Low approach temperature cooling towers The cooling towers is Bangalore are designed for a design wet bulb temperature of 75 o F and leaving cooling water temperature of 85 o F. That means they are designed for an approach temperature of 10 o F. Lower approach temperature means more cooling of hot entering cooling water and lower leaving cooling water temperature. The chiller efficiency depends on entering condenser water temperature and if these temperatures are lower than the design entering temperature the efficiency of the chillers improves. It is therefore recommended that cooling towers shall be designed to an approach temperature equal to or less than 5 o F. GUIDELINE 6: Replace existing equipment by minimum 3 star rated BEE labeled appliances equipment and use minimum 3 star rated BEE labeled appliances/equipment in all new buildings

All the new buildings have to be equipped with the appliances labeled by Bureau of Energy Efficiency (BEE). BEE has labeled refrigerators, Tube lights, distribution transformer, airconditioners and induction motors. Minimum 3 star rated appliances should be used. Retrofit and replacement in existing premises shall be made only by minimum 3 star rated BEE labeled appliances Note: (As of January 2010, Labeling is mandatory for frost free refrigerator, air conditioner, tubular fluorescent lamp and distribution transformer. Minimum level of labeling is 1 star)

Mandatory requirement in all procurement norms for government and public buildings All the new buildings have to be equipped with the appliances labeled by Bureau of Energy Efficiency (BEE). BEE has labeled refrigerators, Tube lights, distribution transformer, air conditioners and induction motors. Minimum 3 star rated appliances should be used. Retrofit and replacement in existing premises shall be made only by minimum 3 star rated BEE labeled appliances

6.1 Guidance Notes

Efficient air conditioners ACs (air conditioners) are used to cool or heat a room and usually consume the highest energy among all home appliances. Window ACs and split ACs are most commonly used. These are available in different sizes– 0.75 tonne, 1tonne, 1.5 tonne, and 2 tonne. Insulation of the walls, roof, and efficient windows in the room would allow one to pick an AC with lesser tonnage. The energy consumption of an AC depends on its size. A 1tonne AC is appropriate for a 150 sq ft room, while a 2tonne AC is sufficient for a room, which is 300 sq ft in area. Use of BEE labeled air conditioners help save energy and must be used.

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Installing an AC While installing an AC, ensure that the exterior (or back) of the AC is not exposed to direct sunlight and is away from heat sources such as chimneys. Efficient airflow across the exterior would ensure efficient operation of the AC. Make sure that air does not escape through doors and windows by sealing them properly. This would help in reducing energy consumption. To optimize the efficiency of the AC ensure that equipments such as televisions, computers or lamps are placed away from it.

Operating an AC The energy consumed by an AC is also affected by its operation. Set the temperature higher to reduce energy consumption. It is ° estimated that a temperature setting of 23 C consumes 10% more ° energy than a temperature setting of 26 C. A few ACs equipped with the ‘sleep’ mode enable savings during operation.

Maintaining an AC Regular maintenance of ACs helps in improving their efficiency. Clean the filters of the AC at least once in 15 days to ensure efficient airflow and cooling. Also, to enable the AC to operate efficiently, the exterior part (or back) of the AC should be free fromdust, preventing blockage.

Refrigerators Refrigerators are one of the highest consumers of electricity in houses. However, they have become significantly efficient in the past few years, and are still improving. A typical refrigerator has a lifespan of 15–20 years. The cost of running it over that time period is several times the initial purchase price. So buy the most efficient model available; investing a little more in a refrigerator with higher efficiency offers solid payback. When you buy a new refrigerator, buy the most efficient model available. A listing of energy efficient appliances can be found at the Bureau of Energy Efficiency's website www.bee-nic.in & www.energymanagertraning.com.

Smaller models will obviously use less energy than larger models. Generally, the larger the refrigerator, the greater the energy consumption. Don't buy a refrigerator that's larger than you need. But one large refrigerator will use less energy than two smaller ones with the same total volume. Models with top or bottommounted freezers average 12% less energy use than sidebyside designs.

Features like throughthedoor ice, chilled water, or automatic icemakers increase the energy consumption, purchase price and also greatly increase energy use and are far more likely to need service and repair. Avoid these costly, troublesome options. 96 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Be willing to pay a bit more initially for lower operating costs. A fivestar refrigerator that costs more initially, but costs less per year to operate due to better construction and insulation, will pay for itself in less than four years compared to a twostar refrigerator. Recycle older or second refrigerators. Don’t keep the old, inefficient refrigerator running in the occasional refreshments. It could cost you significantly more per year in electricity. Star rating plan for various appliances as per Bureau of Energy Efficiency.

6.1.1 Star rating for frost free refrigerator The star rating parameters knf (Constant Multiplier (kWh/Litre/Year)) & cnf (Constant Fixed Allowance (kWh/Year)) shall be obtained from TABLE 2.2 / 2.3, depending on the year of manufacturing/import/assembling The following equation shall be used to determine the Star Rating Bands for a particular model:

Star Rating Band (SRB) nf = k nf * V adj_tot_nf + cnf Where,

knf = Constant Multiplier (kWh/Litre/Year)

Vadj_tot_nf = Total Adjusted Storage Volume for No Frost (Litre)

cnf = Constant Fixed Allowance (kWh/Year)

Table 6.1: Star Rating Band valid from 01 January 2009 to 31 December 2011

Star Rating Band knf cnf Constant Multiplier Constant Fixed Allowance 1 Star * 0.5578 486 2 Star * * 0.4463 389 3 Star * * * 0.3570 311 4 Star * * * * 0.2856 249 5 Star * * * * * 0.2285 199

Table 6.2: Star level valid from the date of publication of these regulations till 31.12.2011

Star Rating Band Minimum CEC Maximum CEC 1 Star * ≥ 0.8716* V adj_tot_nf +759 <0.6973 * Vadj_tot_nf +607 2 Star * * ≥ 0.6973* V adj_tot_nf +607 <0.5578 * Vadj_tot_nf +486 3 Star * * * ≥ 0.5578* V adj_tot_nf +486 <0.4463 * Vadj_tot_nf +389 4 Star * * * * ≥ 0.4463* V adj_tot_nf +389 <0.3570 * Vadj_tot_nf +311 5 Star * * * * * ≥ 0.3570* V adj_tot_nf +311

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Table 6.3: Star Rating Band valid from 01 January 2012 to 31 December 2013

Star Rating Band knf cnf Constant Multiplier Constant Fixed Allowance 1 Star * 0.4463 389 2 Star * * 0.3570 311 3 Star * * * 0.2856 249 4 Star * * * * 0.2285 199 5 Star * * * * * 0.1828 159

Table 6.4: Star level valid from 01.01.2012 to 31.12.2013

Star Rating Band Minimum CEC Maximum CEC 1 Star * ≥ 0.6973* V adj_tot_nf +607 <0.5578 * Vadj_tot_nf +486 2 Star * * ≥ 0.5578* V adj_tot_nf +486 <0.4463 * Vadj_tot_nf +389 3 Star * * * ≥ 0.4463* V adj_tot_nf +389 <0.3570 * Vadj_tot_nf +311 4 Star * * * * ≥ 0.3570* V adj_tot_nf +311 <0.2856 * Vadj_tot_nf +249 5 Star * * * * * ≥ 0.2856* V adj_tot_nf +249

6.1.2 Star Rating Room Air Conditioners The star rating parameters EER shall be obtained from TABLE 2.1, depending on the year of manufacturing/import/assembling

Table 6.5: Star Rating Band valid from 01 January 2010 to 31 December 2011

EER (W/W) Star Rating Min Max 1 Star * 2.30 2.49 2 Star ** 2.50 2.69 3 Star *** 2.70 2.89 4 Star **** 2.90 3.09 5 Star ***** 3.10

6.1.3 Star Rating Direct Cool Refrigerator

The star rating parameters kdc (Constant Multiplier (kWh/Litre/Year)) & c dc (Constant Fixed Allowance (kWh/Year)) shall be obtained from TABLE 2.2 / 2.3, depending on the year of manufacturing/import/assembling.

The following equation shall be used to determine the Star Rating Bands for a particular model: 98 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Star Rating Band (SRB)dc = k dc * V adj_tot_dc + c dc Where,

Kdc = Constant Multiplier (kWh/Litre/Year)

Vadj_tot_dc = Total Adjusted Storage Volume for Direct Cool (Litre)

Cdc = Constant Fixed Allowance (kWh/Year)

Table 6.6: Star Rating Band valid from 01 January 2009 to 31 December 2011

Star Rating Band kdc cdc Constant Multiplier Constant Fixed Allowance 1 Star * 0.413 346 2 Star * * 0.330 277 3 Star * * * 0.264 221 4 Star * * * * 0.211 177 5 Star * * * * * 0.169 141

Table 6.7: Star Rating Band valid from 01 January 2012 to 31 December 2014

Star Rating Band kdc cdc Constant Multiplier Constant Fixed Allowance

1 Star * 0.330 277 2 Star * * 0.264 221 3 Star * * * 0.211 177 4 Star * * * * 0.169 141 5 Star * * * * * 0.108 91

6.1.4 Star Rating Plan: Ceiling Fans Parameters to be tested: Parameters for initial, verification and challenge testing are the mandatory type tests listed under clause 10 of IS 374: 1979 and including all amendments as of date relevant to the determination of service value. These tests would generally include • Air delivery • Fan speed & power input

Conditions of compliance: The performance requirements will be in accordance with clause 8 of prevalent IS 374:1979. For compliance with the requirements of this standard, the values of service factor & air delivery are as listed in table below for 1200mm sweep operating at rated voltage and rated frequency at full speed. 99 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

The star rating plan for ceiling fans is as follows: Star Rating Index Calculation for Ceiling Fans Star Rating Service Value for Ceiling Fans* 1 Star ≥ 3.2 to < 3.4 2 Star ≥ 3.4 to < 3.6 3 Star ≥ 3.6 to < 3.8 4 Star ≥ 3.8 to < 4.0 5 Star ≥ 4.0

*Where x is the base service value as per IS 374:1979. BEE has proposed a base service value of 3.2 at present and would upgrade it to higher value once the BIS value is finalised. *The BIS has proposed from the year 2010 the service value of 3.5. *All ceiling fans covered under this standard shall comply with minimum Air Delivery of 210 cu m/min.

6.1.5 Star Rating Plan: Electric Geysers The Star Rating plan for a stationary type storage electric water heaters shall be based on the Standing Losses(kwh/24hour/45_ C difference) calculated the as per IS 2082:1993. The star rating plan is as indicated below:

Table 6.8: Star Rating Plan for Stationary Storage Type Electric Water Heaters Rated 1 Star 2 Star 3 Star 4 Star 5 Star Capacity (Liters) Capacity(Liters) Standing Losses (kwh/24 hour / 45_C)

6 ≥ 0.792 & ≥ 0.634 & ≥ 0.554 & ≥ 0.475& ≥0.396 >0.634 >0.554 >0.475 >0.396

10 ≥ 0.990&>0.792 ≥0.792&>0.693 ≥0.693&>0.594 ≥0.594&>0.495 ≥ 0.495

15 ≥ 1.138&>0.910 ≥ 0.910&>0.797 ≥ 0.797&>0.683 ≥ 0.683&>0.569 ≥ 0.569

25 ≥ 1.386&>1.109 ≥ 1.109&>0.970 ≥ 0.970&>0.832 ≥ 0.832&>0.693 ≥ 0.693

35 ≥ 1.584&>1.267 ≥ 1.267&>1.109 ≥ 1.109&>0.950 ≥ 0.950&>0.792 ≥ 0.792

50 ≥ 1.832&>1.466 ≥ 1.466&>1.282 ≥ 1.282&>1.099 ≥1.099&>0.916 ≥ 0.916

70 ≥ 2.079&>1.663 ≥ 1.663&>1.455 ≥ 1.455&>1.247 ≥ 1.247&>1.040 ≥ 1.040

100 ≥ 2.376&>1.901 ≥ 1.901&>1.663 ≥ 1.663&>1.426 ≥ 1.426&>1.188 ≥ 1.188

140 ≥ 2.673&>2.138 ≥ 2.138&>1.871 ≥ 1.871&>1.604 ≥ 1.604&>1.337 ≥1.337

200 ≥ 2.970&>2.376 ≥ 2.376&>2.079 ≥ 2.079&>1.782 ≥ 1.782&>1.485 ≥ 1.485

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6.1.6 Star Rating Plan Colour Televisions

BEE will make On Mode and Standby data available on the BEE Web site ( www.beeindia. nic.in ) for interested consumers. Additionally, BEE will also provide consumers with an estimate of each Star label qualified TV’s annual energy consumption through display of a kWh/year number. This annual power consumption estimate will be based on a daily usage pattern of 6 hours in On Mode and 12 hours in Standby Mode.

Annual Power Consumption: To qualify as BEE Star labeled product, all TVs, TV Combination Units, must not exceed the maximum Annual Power Consumption (APCmax) found from the equations in Table 2 and 3, based on the unit’s native vertical resolution and visible screen area. The maximum annual power consumption is expressed in kilo watts per year and rounded to the nearest whole number. In the following equations, ‘A’ is the viewable screen area of the product, found by multiplying the display width by the display height. Equations are provided in both standard units inches2 and centimeter2. As an example, maximum allowed power consumption for TV products of various screen sizes is also provided below in Table 4, 5 and 6.

Table 6.9: Star Rating Equations for CRT TV’s from 1st January 2010 onwards Star Rating Maximum Annual Power Consumption

1 – Star (Max Annual Power Consumption in kWh/Year) P = (0.964 x A) + 4.38

2 – Star (Max Annual Power Consumption in kWh/Year) P = (0.876 x A) + 4.38

3 – Star (Max Annual Power Consumption in kWh/Year) P = (0.788 x A) + 4.38

4 – Star (Max Annual Power Consumption in kWh/Year) P = (0.701 x A) + 4.38

5 – Star (Max Annual Power Consumption in kWh/Year) P = (0.613 x A) + 4.38

Table 6.10: Star Rating Equations for LCD and Plasma TVs Star Rating Maximum Annual Power Consumption

1 – Star (Max Annual Power Consumption in kWh/Year) P = (0.964 x A) + 4.38

2 – Star (Max Annual Power Consumption in kWh/Year) P = (0.876 x A) + 4.38

3 – Star (Max Annual Power Consumption in kWh/Year) P = (0.788 x A) + 4.38

4 – Star (Max Annual Power Consumption in kWh/Year) P = (0.701 x A) + 4.38

5 – Star (Max Annual Power Consumption in kWh/Year) P = (0.613 x A) + 4.38 Where A = Screen area in square inches

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Table 6.11: Star Rating Equations for CRT TV’s from 1st January 2010 onwards Star Rating Maximum Annual Power Consumption 1 – Star (Max Annual Power Consumption in kWh/Year) P = (0.1494 x A) + 4.38 2 – Star (Max Annual Power Consumption in kWh/Year) P = (0.1358 x A) + 4.38 3 – Star (Max Annual Power Consumption in kWh/Year) P = (0.1222 x A) + 4.38 4 – Star (Max Annual Power Consumption in kWh/Year) P = (0.1086 x A) + 4.38 5 – Star (Max Annual Power Consumption in kWh/Year) P = (0.0950 x A) + 4.38

Table 6.12: Star Rating Equations for LCD and Plasma TVs Star Rating Maximum Annual Power Consumption

1 – Star (Max Annual Power Consumption in kWh/Year) P = (0.1494 x A) + 4.38

2 – Star (Max Annual Power Consumption in kWh/Year) P = (0.1358 x A) + 4.38

3 – Star (Max Annual Power Consumption in kWh/Year) P = (0.1222 x A) + 4.38

4 – Star (Max Annual Power Consumption in kWh/Year) P = (0.1086 x A) + 4.38

5 – Star (Max Annual Power Consumption in kWh/Year) P = (0.0950 x A) + 4.38

Where A = Screen area in square centimetre

Table 6.13: Star Rating Bands for CRT TV’s of Typical Screen Sizes from 1st January 2010 Screen Screen Max Annual Power Consumption for (kWh/Year) Size Area (sq 1 2 3 4 5 (inches) inches) Star Star Star Star Star

A P = (0.964 x P = (0.876 x P = (0.788 x P = (0.701 x P = (0.613 x A) + 4.38 A) +4.38 A) + 4.38 A) + 4.38 A) + 4.38

14 94.1 95 87 79 70 62

21 211.7 208 190 171 153 134

29 403.7 394 358 322 287 252

32 491.5 478 435 392 349 306

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Table 6.14 : Star Rating Bands for LCD and Plasma TV’s for Typical Screen Sizes Energy Consumption Allowances for LCD and Plasma

Screen Screen Max Annual Max Annual Max Annual Power Max Annual Max Annual Size Area (sq Power Power Consumption for 3 Power Power Consumption (inches) inches) Consumption for Consumption Star (kWh/Year) Consumption for 1 for 2 for 4 5

Star (kWh/Year) Star (kWh/Year) Star (kWh/Year) Star (kWh/Year)

P = (0.964 x A) + P = (0.876 x A) P = (0.788 x A) + 4.38 P = (0.701 x A) + P = (0.613 x A) + 4.38 +4.38 4.38 4.38

20 170.9 169 154 139 124 109

26 288.9 283 257 232 207 181

32 437.6 426 388 349 311 273

37 585.0 568 517 465 414 363

42 753.8 731 665 598 533 466

46 904.2 876 796 717 638 559

50 1068.2 1034 940 846 753 659

55 1292.6 1250 1137 1023 910 797

Table 6.15: Star Rating Bands for LCD and Plasma TV’s for Typical Screen Sizes Energy Consumption Allowances for LCD and Plasma Screen Screen Max Annual Max Annual Max Annual Max Annual Max Annual Size (cm) Area (sq Power Power Power Power Power cm) Consumption for Consumption for Consumption for Consumption for Consumption for 1 2 3 4 5 Star (kWh/Year) Star (kWh/Year) Star (kWh/Year) Star (kWh/Year) Star (kWh/Year) P = (0.964 x A) + P = (0.876 x A) P = (0.788 x A) + P = (0.701 x A) + P = (0.613 x A) + 4.38 +4.38 4.38 4.38 4.38 50.8 434.1 169 154 139 124 109 66.0 733.8 283 257 232 207 181 81.3 1111.5 426 388 349 311 273 94.0 1485.9 568 517 465 414 363 106.7 1914.7 731 665 598 533 466 116.8 2296.7 876 796 717 638 559 127.0 2713.2 1034 940 846 753 659 139.7 3283.2 1250 1137 1023 910 797

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6.1.7 Why is this required? Today the market is full of variety of equipment. For various equipment and appliances of common use, there is wide variation in energy consumption of products made by different manufacturers. Further, information on a product’s energy consumption is often not easily available or easy to understand. This may lead to excessive use of energy. In this case it becomes difficult for customer to select the appliance. In such case selecting the labeled appliance is an easier way. An appliance is rated based on its performance and energy consumption. Purchasing a labeled appliance not only provides better performance, but also has reduced consumption as compared to the conventional equipments.

6.1.8 How is it beneficial? The Energy Rating label enables consumers to compare the energy efficiency of domestic appliances on a fair and equitable basis. It also provides incentive for manufacturers to improve the energy performance of appliances. The appliance is rated according to their performance. Rating schemes allow comparing the environmental performance of similar products. This allows more informed choices for consumers and a means to measure progress in reducing our environmental impacts. The present rating, applicable in India is given by BEE.One can identify the labelled appliance by symbol shown in figure. The labeled appliances carry symbol of stars. More number of stars show more efficiency of the product.

Advantages of using labeled appliances are • Increased efficiency of appliances • Better performance • Cleaner technologies, less wastes are released • Reduced energy consumption • Protection of environment

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The efficiency of an AC is determined by its energy efficiency ratio or EER (ratio of coiling output to total electric energy input) The number of stars on the BEE (Bureau of Energy Efficiency) label indicates the efficiency of an AC; the higher the number of stars the more efficient the appliance. For instance, a BEE 3star (EER of 2.7) rated 1.5tonne window AC would consume 1500 units of electricity in a year (205 days @ 6 hours/day operation per year) compared to a 1 star rated (EER of 2.3) of the same size that would consume 1750 units during the same period. An efficient 3 star 1.5tonne AC would cost about Rs 19500, whereas an 1 star AC would cost about Rs 18 000. The additional Rs 1500 invested on the efficient AC will be recovered in a little over one year due to savings in the electricity bill.

Refrigerators are one of the highest consumers of electricity in houses. However, they have become significantly efficient in the past few years, and are still improving. A typical refrigerator has a lifespan of 15–20 years. The cost of running it over that time period is several times the initial purchase price. Comparison between a specific make of 5 star vis a vis 3 star refrigerator showed that the initial incremental investment pays back in the 3rd year of operation itself. GUIDELINE 7: Solar Water Heating Systems for Domestic and commercial buildings

Provide solar water heating system for residential, commercial and institutional buildings to meet the byelaw requirement or a minimum of 50% of water heating requirement on annual basis, whichever is higher. Insulation on pipelines should be provided as mentioned in the guidance notes Water re circulating pump to reduce wastage should be provided in high rise buildings ( in high rise buildings, the line losses may result in stagnated cold water in the distribution pipeline that connect hot water tank to individual households. This happens at night time when the ambient temperature reduces. As result of this, during morning usage hours, the cold water has to be flushed out of the line before hot water supply from the tank is circulated. A small pump can be designed to recirculate the cold water in the pipeline.

7.1 Mandatory requirement in byelaw

Current provision The building bye law of Bangalore has the following provision for installation of solar water heating system: Solar lighting and solar water heating is mandatory for all new development / constructions as per Table 10 for different categories of buildings. If solar Lighting and Solar Water heating is adopted, then refundable security deposit on fulfilling the conditions shall be returned along with 2% interest.

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Table: (Bye law 3.4.10) Solar lighting and water heater requirements

Sl. Type of use 100 liters per day shall be provided for No. every unit 1 Restaurants serving food and drinks with seating / serving area of more than 100 40 sq. m. of seating or serving area sq. m and above 2 Lodging establishments and Tourist Homes 3 rooms 3 Hostel and guest houses 6 beds / persons capacity 4 Industrial canteens 50 workers 5 Nursing homes and hospitals 4 beds 6 Kalyana Mandira, Community Hall and Conventional hall (with dining hall and 30 sq. m of floor area kitchen) 7 Recreational clubs 100 sq. m of floor area 8 Residential buildings a)Single dwelling unit measuring 200 sq.m of floor area or site area of more than 400 sq.m whichever is more 9 b) Solar photovoltaic lighting systems shall be installed in multi unit residential buildings (with more than five units for lighting the set back areas and drive ways)

Revision proposed • Provide solar water heating system for residential, commercial and institutional buildings to meet the byelaw requirement or a minimum of 50% of water heating requirement on annual basis, whichever is higher.

• The following typologies of buildings should be added to the list of building with mandatory provision for solar water heating:

Office buildings Apartment blocks Hotels • Existing buildings shall also be required to install solar water heating system as per the above requirement. Pre-feasibility shall be carried out to determine applicability.

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It is felt that sizing norms can be developed based on water heating needs for various applications and reflected in the bye law provisions Some of sizing norms that could be applied are as follows:

Guidelines for system sizing Hot water demand can be assumed as follows. • For bathing (using bucket water) = 15 litres per person per bath (one bucket) • For shower bath = 25 litres per person per bath • For tub bath = 35–50 litres per person per bath • For cooking = 5 litres per person per day • For washing clothes = 10 litres per person per day • For washing utensils = 5 litres per person per meal • For making tea/coffee = 150 ml per person per cup (Consumption figures may vary, depending on the lifestyle, age, habits, and weather conditions) UNDP/GEF is conducting a study (under publication) on assessing the potential of solar water heating systems in India. Some indicative benchmark numbers that are available for estimation of solar water heating requirement for various applications are as follows: Hotels: 4 star and above: 150lpd/room 3 star : 125 lpd/room 2 star and below: 50 lpd/room Hospitals: 30lpd/bed for government/private hospitals 190lpd/bed for multi speciality hospitals Hostels: 30lpd/student

Applying the above , the hot water demand per bed/person for hostel/guest houses can be estimated as follows: • For bathing (using bucket water) = 15 litres per person per bath (one bucket) • For cooking = 5 litres per person per day • For washing clothes = 10 litres per person per day • For washing utensils = 5 litres per person per meal Hence total hot water demand can be estimated as 30-35lpcd and hence 6 beds would require a minimum of 180-210lpd (say 200lpd) instead of 100lpd specified in the current byelaw. The current byelaw provision shall meet 50% of the water heating requirement

Similarly, for industrial canteens,

Applying the above , the hot water demand per worker can be estimated as follows: • For cooking = 5 litres per person per day • For washing utensils = 5 litres per person per meal Hence per person requirement is about 10lpd and hence one 100 lpd is required per 10 workers, in place of 50 workers. The current byelaw provision would thus meet 20% of the hot water need for this application. The apartment blocks that have dwelling units lower than 200 sqm should also be covered by byelaw and provision for solar water heating system should be mandated. In case of apartment buildings, the available roof area could determine the capacity of solar water heating systems to be provided. 108 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

7.2 Guidance Solar water heating system The system is generally installed on the terrace and requires minimum maintenance. It works automatically and one does not have to operate any part of the system.T ypically, a surface area of 3 sq m is required to install it.The system can also be installed on a southfacing window sill if space is not available on the terrace. Two types of systems are being promoted—one based on FPC (flat plat collectors) and the other on ETC (evacuated tube collectors). The life of FPCbased systems is generally 15–20 years, and they are costlier than ETCbased systems. There are 57 BIS (Bureau of Indian Standards)approved manufacturers of these systems,(the ones in Karnataka have been listed below) and they have had a stable market in the country for the last many years. ETCbased systems are relatively new and could be more reliable for colder regions and regions that have hard water. The life of these systems is, however ,less since their collectors comprise glass tubes, which are fragile. .The installation of a solar water heating system in a home/building needs to be planned at the time of its construction. The following points may be kept in mindwhile planning for the same.i) A 34 sq m (per 100 lpd system) shadowfree areashould be available on the terrace for installation.

Solar water-heating system components The main components of a solar waterheating system are Solar collectors, Insulated hot water tank, Backup system, Plumbing, and Control and instruments.

Solar Collectors: Solar collectors are of two types, Flat plate solar collectors and Evacuatedtube Collector or vacuum tube solar collectors.

Hot water tank: Solar water heating tanks are made of stainless steel, copper, or mild steel, with a heatresistant protective coating inside for avoidance of corrosion. To reduce heat losses, the tanks are insulated with rockwool insulation pads or polyurethane foam. The insulation is covered with aluminium sheet cladding, reinforced fibreglass, FRP (fibre glass reinforced plastic) cover, or suitable grade plastic cover. The tanks are available in a variety of shapes, sizes, and colours.

Plumbing: Galvanized iron pipes and fittings of BISapproved class ‘B’ or higher are normally used for the plumbing in solar water heating systems. Piping for a solar water 109 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

heating system should be well insulated to minimize thermal losses. The insulation should be further protected by suitable aluminium, FRP, or HDPE (high density polyethylene) pipe cladding. Various insulation materials – such as asbestos rope, glass wool, rock wool, or PUF (polyurethane foam) – are used as insulation. For pipes measuring up to 25 mm in diameter, insulation of 25 mm thickness is recommended. Insulation of 50 mm thickness is recommended for pipes with 25–75 mm diameter. If hot water pipes are concealed in walls, they must be insulated; otherwise, there is a chance of the walls developing cracks due to expansion of the metallic pipes. For concealed pipes, asbestos rope is normally used for insulation; however, it is recommended to use 25mmthick rock wool/glass wool insulation. Nowadays, composite pipes and polymer pipes, which are considered suitable for hot water applications, are also available.

Controls and instrumentation Valves are used for control of water flow. Gate valves or ball valves of suitable ratings are used. Pressure and vacuum release valves or open vents are provided to take care of the pressure buildup or vacuum formation problems. A temperature gauge is provided for temperature measurement. Additionally, thermostatic controllers, electronic temperature controllers, and pumps are provided for large systems.Use a proper vent or vacuumrelease valve / pressurerelief valve for safe operation of the solar water heating system

Types of solar water heating system There are two types of solar water heating systems: • Thermo siphontype solar hot water system For capacities of up to 2000 liters per day. • Forced flow solar hot water system For capacities higher than 2000 liters per day.

Back-up system: Solar water heating system output depends on the availability of solar energy. In order to meet hot water requirements during periods of low sunshine, a backup system is used. Typically, an electrical heater is provided in the hot water tank of the solar water heating system for this purpose. The backup heater is also useful in meeting the additional hot water requirements, over and above its designed capacity. In some cases, a conventional storage electrical geyser is also used as backup.

7.2.1 Guidelines for design, installation, and use of solar water heating systems • Solar collector should face true south for maximum solar radiation collection. • The solar collector tilt should be equal to the latitude of the place for maximum annual energy collection. • The solar collector tilt equal to latitude +15° gives maximum energy collection in winter. • Solar collector tilt equal to latitude 15° gives maximum energy collection in summer. 110 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

• Always check the loadcarrying capacity of the roof before placing the solar water heating system. Typically, each solar collector with a 2 m2 area weighs approximately 50 kg. When filled with water, the solar tank weighs about 1.2–1.4 kg per litre capacity of the tank (for example, a 100litre capacity tank weighs around 120–130 kg). • Ensure proper anchoring of the system, duly considering wind conditions. • Solar collectors and tank must be easily accessible for cleaning and maintenance. Typically, the solar water heating system requires approximately 1.3–1.5 times collector area for installation. For example, a singlecollector system with a capacity of 100 litres and an area of 2 m2 needs about 3 m2 of floor area for installation. • Gap between nearest tall building and collector surface should be at least twice the building height for buildings in south and east west sides. • Plumbing to be insulated and if possible inside the wall. • Check water quality TDS /hardness should be less than 100 ppm consult expert if some minerals are more ( refer ISI standard for water quality)

7.2.2 Guidelines for system selection and use • Check the hardness of the water to be used in the solar water heating system. Solacollectors have small diameter pipes, which get blocked due to the deposition of salt from hard water. In cases of hard water, either a water softener or a heat exchangertype solar water heater can be used. • It is a good practice to consider the location of the solar water heating system and optimize the associated hot/cold water piping layout during the building design stage, to reduce cost and heat losses caused by longer piping. • Always use good quality pipes and insulation for longer userlife and troublefree working. • It is important to check the operating pressure of the cold water supply line, especially when pressurized water is circulated. Most solar water heating systems available in India are not designed for pressurized water supply.

7.2.3 Guidelines for insulated hot water piping • Heat losses in hot water piping can account for more than 30% of water heating energy. These can be reduced by optimising the length of the hot water piping (minimizing enduse to storage tank distance) and properly insulating the storage tank and piping. • Reduce construction costs and heating losses by locating the solar water heater in close proximity to showers, washing machine, and kitchen. • Use jute rope for insulation as this is a cheap option. However, it is recommended that preformed insulation pipe section or foam pipe section, preinsulated pipes, and polymer/composite pipes – suitable for high temperature applications (up to 100 °C) – are used. Polymer/composite pipes have lower thermal capacity and lower thermal 111 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

conductivity compared to GI (galvanized iron)/copper pipes, resulting in lower heat losses as they have better corrosion resistance than metal pipes. While using metal pipes, use the BISapproved class ‘B’ or higher quality GI. • Set water heater temperature to an optimu level. The human body can tolerate temperatures up to 45 °C. Human skin burns at water temperatures above 55 °C. Therefore, storage water heater temperature can be set at approximately 55(+5) °C.

7.2.4 How is it beneficial?/Why is this required?

The overall potential in India is estimated to be 140 million sq. m. of collector area. About 1 million sq. m. of solar collector area is estimated to have been installed in the country over the past two decades. The achievement made so far is, therefore, modest compared to such a potential, and also in relation to what has been achieved in other countries, particularly in China

A solar water heater is a device that uses heat energy of the sun to provide hot water for various applications. In homes, it is useful for bathing, washing, cleaning, and other chores. A domestic solar water heater, with a capacity of 100 lpd (litres per day), is sufficient for a family of four or five members. It can easily replace a 2kW electric geyser and can save up to 1500 units of electricity a year. It pays back the cost in three to five years depending on the electricity tariff and hot water use in a year. After this, hot water is available almost free of cost during remaining lifespan of the system, which is about1520 years. The cost of solar water heaters, with a capacity of 100 lpd) varies between Rs 18 000 and Rs 25 000. To offset the initial high price, a set of incentives are available that are listed below.

The city of Bangalore is in temperate climate zone of India. Hot water is required round the year for daily domestic needs . It has been estimated (using computer simulation tool RETSCREEN) that energy demand to cater to hot requirement of 100 lpd at 60 deg C (for 10.5 months annually) is 1.34 mWh of which about 0.921.00 MWh can be supplemented using solar energy for water heating. The payback period (taking into account the interest subsidy offered through schemes of the Ministry of New and Renewable Energy, Government of India) is about 3.5 years. Soft loans are available for installation of Solar Water Heating Systems underthe MNRE SWH Scheme. The detail of Soft loan is as given below: a) Domestic : 2% b) Institutions : 3% c) Commercial : 5%

• Capital subsidy equivalent to upfront interest subsidy has been introduced to registered institutions and registered commercial establishments that do not avail soft loans. 112 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

The detail of capital subsidy is as given below: @ Rs.1100/- per sq.m. of collector area will be available to registered institutions and @ Rs.825/- per Sq.m. of collector area to registered commercial establishments. The main objective of the Scheme is to promote the widespread use of solar water heaters through a combination of financial and promotional incentives.

• The subsidy will be provided on reimbursement basis after the systems have been installed. The applications are to be submitted to the State Nodal Agencies. • SNAs will be provided service charges @ Rs.100/ sq. m. of installed collector area. • The Municipal Corporations, Central/State Govt. departments will also be eligible to receive similar service charges for the claims processed and forwarded by them to the Ministry. • To encourage the use of solar water heaters, which helps in reduction of peak loads, the rebate of 50 ps per unit with a maximum limit of Rs. 50 per installation is being provided by all Electricity Supply Companies.

List of solar water heater manufacturers/providers in Bangalore Sl. Name Address Contact No. No 1 M/s. Sundrop Solar 44/2a, Industrial Estate, Tel : 23620077 Systems Opp Gangadhareshwara Kalyana Mantapa Mobile : 9844068721 NH 7, Bellary Road, Hebbal Web : www.sundropsolar.net Bangalore 560024 2 M/s. Sudhanva 65/18, 1st Main,0 7/08/2008 Tel : 28366832, Mobile : Industries 1st Cross, Andrahalli Main Road, 9845313912 Hegganahalli, Bangalore Email : [email protected] Pin : 560091 3 M/s. Kinara Power Unit 2, 10,10th Cross, Patel Channappa Indl Estate, Tel : 28365944 Systems and Projects Andrahalli Main Road, Peenya 2nd Stage, Pvt Ltd, Viswaneedum Post, Bangalore 560091

4 M/s. Om Shakthi No2 S.T. Narayana Gowda Industrial estate, Tel : 28362967,56982645 Industries, Sri Gandha Nagar, Doddanna Industrial Estate, Mobile : 9448062867 Near Peenya II Stage, Email : Bangalore 560091. [email protected] 5 M/s. Sabha Solar 3/1 Behind Balaji Petrol Bunk, Energy, 2nd Cross, Lakshmaiah Block, Ganganagar, Bangalore560032 Pin : 560032 113 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

6 M/s. Velnet Non No 120, Bhadrappa Layout, Tel : conventional Energy Ring Road, Nagashettyhalli, 23418630,23417940,23512799 Systems(P) Ltd., Bangalore 560094 Mobile : 9844050723 Email : [email protected] Web : www.kamalsolar.com 7 M/s. Enolar Systems, 45/291, Gubbanna Industrial Estate, Tel : 23355333/23385500 6th Block, Rajajinagar, Fax : 23355333 Bangalore 560010 Email : [email protected] 8 M/s. Divya Industries, No 814, Chowdeshwari Nagar, Tel : 8398471 Laggere Main Road Laggere, Peenya Post, Email : [email protected] Bangalore Pin : 560058 9 M/s. Shringar System Pvt Ltd, No 93 7th Main 3rd Tel : 28398197 Engineering & Energy Phase, Peenya Industrial Area, Email : [email protected] Bangalore 560058 10 M/s. Perfect Solar No.16 Byraveshwara Industrial Estate, Tel : 28362515/1129 Bangalore Pvt Ltd, Andrahalli Main Road, Peenya 2nd Stage Fax : 28362515 Bangalore Mobile : 9845106037 Email : [email protected] 11 M/s. Sunrise Solar Pvt B4, Jayabharat Industrial Estate, Tel : 23328533,23523644 Ltd, Yeshwanthpur, Fax : 23425115 Bangalore – 560022 Email : [email protected] Web : www.sunrisesolarsystem.com 12 M/s. Sustainable Power 604/677, Magadi Road, Tel : 23580066,23581154 Developers India Pvt P&T Layout Road, Sunkadakatte, Ltd, Bangalore 560079 13 M/s. Tata BP Solar India Plot No. 78, Electronic City Phase – 1, Tel : 08056601300 Ltd Hosur Road, Fax : 08028520972/28520116 Bangalore – 560100 Email : [email protected] Web www.tatabpsolar.com 14 M/s. Kotak Urja Pvt Ltd, 378 10th Cross, 4th Phase, Tel : 28363330,28362136 Peenya Industrial Area, Fax : 28362347 Bangalore 560058 Email : [email protected] Web ; www.kotakurja.com 15 M/s. Emmvee Solar Survey No 13/1 Bellary Road, Jala Email : [email protected] Systems Pvt Ltd, Hobli Sonnapanahalli, Bettahalsur Post, Web : www.emmveesolar.com Bangalore 562157 16 M/s. Sun Zone Solar ¼, Balagangadhara Nagar, Tel : 23282145, 23214777 Systems, Mallathahalli, Behind Sanfordcollege, Mobile : 56979935 114 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Bangalore 560056 Email : [email protected] 17 M/s. Nuetech Solar P.B.No.9167, B.M. Shankarappa Industrial Estate, Tel : 08023483766,23481905 Systems Pvt Ltd, Sunkadakatte Fax : 08023281730 Vishwaneedam Post Email : [email protected] Magadi Main Road Web: www.neutechsolar.com Bangalore 560091 18 M/s. Solar Energizers P 36/3, 1st Cross, Pukhraj Layout, Tel : 22245481 Ltd, Bannerghatta Road, Adugodi, Fax : 22225804 Bangalore 560030 Email : [email protected] 19 M/s. Dheemanth 35, Behind, Check Post, Kamakshipalya Layout, Tel : 23489377/2342617 Industries, Bangalore 560079 20 M/s. Technomax Solar No 21/B, 4th Main, 1st Cross, Industrial Suburb, Tel : 3418723 Devices Pvt Ltd, Yeshwanthpur, Bangalore – 560022 21 M/s. Digiflic Controls Sit2e8 /03/2008 No. 9, 2nd Cross, Tel : 08028366839 (India) Pvt Ltd, Rajagopala Nagar, Main Road Fax : 08028362689 Bangalore Email : [email protected] Pin : 560058 22 M/s. Kateel Engineering 19 & 20, Bhadrappa Estate, Tel : 23481305,23484179 Industry (P) Ltd Magadi Main Road, Fax : 23481305 Kamakshipalaya, Unit I Email : [email protected] Bangalore Pin : 560079 23 M/s Solar Hitech No. 4, Sri Krishna, Behind Bhima Jyothi LIC Colony, Fax: 08023223152, 23221511 Geysers West of Chord Road, Bangalore – 560 079 email: [email protected] 24 M/s. EmmVee Solar #55, “Solar Tower”, 6th Main, 11th cross, Tel: 08023337428, Fax: 080 Systems Pvt. Ltd., Lakshmaiah Block, Ganganagar, 23332060 Bangalore – 560 024. email: [email protected] 25 M/s. Vijaya Industries, Katapady – 574 105, Udupi Dist, Karnataka Tel: 08202557127 Fax: 08202557327, Mobile: 09448377327 email: [email protected] 26 M/s. Rashmi Industries, No.60 & 61, Begur Road, Hongasandra, Bangalore – Tel: 08025734114 / 15 560 068 email: [email protected] website: www.rashmisolar.com 27 M/s. Orb Energy Pvt. No.893, 3rd Cross MC Layout Vijayanagar, Tel: 0802314593135,Fax: Ltd., Bangalore – 560 040 08023145930 115 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

email: [email protected] website: www.orbenergy.com 28 M/s. Anu Solar Power 248 3rd Cross, 8th Main, 3rd Phase Peenya Tel: 08028394259, 28393913 Pvt. Ltd., Industrial Area, Bangalore – 560 058. email: [email protected] website: www.anusolar.com 29 Wipro Eco Energy (A Wipro Eco Energy, S.B.Towers. Tel: 08041994004, 91 division of Wipro Ltd.) 88, MG Road, Bangalore560001 9900582662 [email protected] 30 M/s Hamshine B.Katehalli Industrial Area, Plot No.7A/1, Tel: 8172240219 Electronics & Energy Hassan – 573201 (Karnataka) Mob: 9448140219 System email: [email protected] 31 M/s. Legend Solar 295B, KIADB Industrial Area Bommasandra – Jigani Tel: 807825595 , Energy Systems Private Link Road, Jigani Bangalore. email: Limited [email protected] website: www.legendkingdom.com 32 M/s. G.C. Solar 977, Ground Floor, ITI Society Layout, Tel: 08023210848/ 23183060/ Industries Outer Ring Road, Nagarabhavi 9845023816 (Mob) Road, Banglore – 560072 Fax: 08023210848 email: [email protected] website: gcsolarindustries.com

GUIDELINES 8: Energy Efficient Electrical Systems for Buildings

8.1 Guideline for Energy Efficient Electrical systems for building

Achieve energy efficient and reliable electrical system design for buildings. Also the guide line should have compliance with the existing BESCOM regulations.

8.1.1 Mandatory clause to be included in the Revised Bye Laws

The power factor of the building should be maintained above 0.95 The transformer no load and full load losses should be in accordance with the conditions specified in ECBC 2007.

8.2 Technical Notes for Electrical systems

Technical guidance to achieve the recommendations

Electrical Systems Electrical System in a building comprises of the infrastructure that brings in electrical supply. The main infrastructures are Electrical Substation, transformers, distribution systems, circuit breakers, Electrical meters, capacitors etc.

The objective of having an efficient electrical system in a building installation is to have energy efficient delivery systems thereby the losses in the electrical infrastructure is kept to minimum. Also the installed electrical system should have suitable safety mechanism for providing reliable power supply.

8.2.1 Guidelines in Electrical system design

A typical electrical distribution facility in a building will generally include the following: • Power distribution systems for equipment, including indoor substation, transformers, building distribution, process control systems, building electrical service systems and protection systems • Power outlet system for movable equipment, materialhandling systems, transportation system • Auxiliary systems like airconditioning & refrigeration, compressed air system, lighting, fire alarms systems, communication and computer based equipment. • D G sets / cogeneration equipment/ UPS/Inverter 117 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

Any system planning should include certain basic considerations as given below that will support the overall flexible design and efficient operation of the electrical system: • Safety of life and property including equipment. • Reliability of system input supply and tolerance limit of interruptions • Flexibility of plant distribution system • Location of the plant substation and its deployment • Data of electrical equipment, regulation and initial cost including capitalisation • Simplicity /flexibility of operation and maintenance • Overall cost including running cost • Providing quality service • Technical parameters and specifications of materials to follow standards in construction, installation, protection, operation and maintenance • Adherence to laid down procedures with accountability

Table 1 indicate possible loss as percentage of full load for few electrical equipment

Table 8.1: Loss percentage in electrical equipments Sl. Equipment % loss of No. max load

A C Motors

i. 750 Watts 7.5 kW 14 35

7.5 kW 150 kW 6 12

150 kW 1000 kW 4 7

Above 1000 kW 2.3 4.5

ii. Transformers 0.4 1.9

iii. Cables 1 4

iv. Switch gear

L.T. 0.13 0.34

Medium voltage up to 11 kV 0.005 0.02

8.2.2 Guidelines on optimization of electrical load

The following steps should be a guide line for initial planning and sanction of the electrical design.

1. Involves load details such as:

• load in kW and demand in kVA

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• diversity factor • load characteristics • future expansion

This includes peak load, load fluctuations under various operating conditions, nature of load, PF and its variation, calculated daily, monthly and annual load factor, and anticipated seasonal variation, effect of large motor starting.

2. Involves anticipation of the present demand over a period of time, peak load, maximum demand and demand, diversity and load factors. 3. Future demand forecasting and planning (building expansion plans). 4. Determination of the voltage level required for the building. Power is fed to a building through a transmission and distribution (T&D) network. This can be provided using either high voltage & low current or vice versa. The selection of the voltage level is determined by current national and international standards, safety regulations and, of course, the economic considerations. Large consumers can reduce energy losses by drawing power at a high voltage level and distribute it inside their premises at required load centres using their own stepdown transformers to match the voltage level to the equipment. 5. Voltage application required in the plant and voltage drops at all levels and at critical points. An industry classification, based on load and preferred incoming voltage, is given in Table 2.

Table 8.2: Industry Classification of Voltage Preferences

Industry Preferred Incoming Voltage Voltage Class as per Level I.E. Rule 100 MW and above 220 kV Extra Between (10 50 MW) 132 66 kV High Between (1 to 10 MW) 33 11 kV High Up to 50 kW 3 φ, 440 Volts Medium/Low

6. Calculation of short circuit analysis and selection of correct rating for circuit breaker with review of selection of protective devices. 7. Station houseservice unit requirement (parallel, standby or emergency operation). 8. Preliminary layout drawing including provisions for future expansion. 9. Detailed single line diagrams, covering all loads/supplies, including main and distribution transformers, switch gear, primary and secondary cabling, protection, insulation level coordination, motor starter panels and capacitor banks.

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8.2.3 Guidelines on Transformer Rating and Selection Most of the transformers used in electrical power systems are threephase transformers. They can be characterized by the vector group and the type of cooling. The vector group (e.g. star connection, delta connection) depends on the internal connection of windings of the high voltage and low voltage side.

Cooling of the transformer is performed by air or a liquid, e.g. oil or askarel with a natural or forced flow. The heat is drawn off using cooling ribs at the surface of the tank. In most cases the power losses can only be ascertained through the test certificate issued by the manufacturer or by carrying out field measurements.

Power transformers of the proper ratings and design must be selected to satisfy the minimum acceptable efficiency at 50% and full load rating. In addition, the transformer must be selected such that it minimizes the total of its initial cost in addition to the present value of the cost of its total lost energy while serving its estimated loads during its respective life span.

The transformer losses for oil cooled transformer for 11 kV and 33 kV is given in table 2. When new transformer is procured the no load and full load losses of the transformer should be in accordance with the ECBC recommended figures as given in table below.

Rating kVA Max. losses at 50% Max. losses at Total losses at 50% Total losses at loading kW 100% loading kW loading kW 100% loading kW Up to 11 kV Up to 22 kV 100 0.5 1.8 0.6 1.8 160 0.8 2.2 0.8 2.6 200 0.9 2.7 0.9 3.0 250 1.1 3.3 NA NA 315 1.1 3.6 1.3 4.3 400 1.5 4.6 1.5 5.1 500 1.6 5.5 2.0 6.5 630 2.0 6.6 2.3 7.6 1000 3.0 9.8 3.5 11.4 1250 3.6 12.0 4.0 13.3 1600 4.5 15.0 4.9 16.0 2000 5.4 18.4 5.7 18.5 2500 6.5 22.5 7.1 23.0

At the time of installation of a new transformer the size is decided based on the expected loading on the transformer. Normally maximum efficiency; of the transformer is designed at the loading in the range of 50 to 65% of' its full load capacity. If the average load is 80% or

120 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

more of the rated power, a bigger transformer or a second transformer should be considered because the shortcircuit losses become a large portion of the total losses.

Capacity and Number of Transformers The main factors which should be taken into account when determining the number and capacity of shop transformers are:

The number of transformers depends upon the operating duty of the station or industry. The load curve may show that the installation of two transformers instead of one is more attractive economically. This is usually the case when the load capacity factor is low (less than or equal to 0.5). In this case disconnecting devices are necessary to connect and disconnect the power transformers to ensure economical operation.

Where possible the installation of either one transformer or two transformers connected through a common circuit breaker should be contemplated. If the reliability of supply necessitates the installation of more than one transformer should be sought. When designing substations, redundancy features (Reserve facility) should be taken care of as follows:

The building should be supplied from two independent sources, where continuity of supply is required. The capacity of the transformers should be so selected that if one of the transformers fails, the remaining transformer shall ensure supply to the equipments without undue overload.

In selecting transformer capacity, it should be ensured for economical operation so that when one of the transformers is out of service, the load on the transformer in operation as far as temperature is concerned shall not affect its service life.

It is always a good practice to provide / or install transformers of one step higher in capacity. For example: If two transformers each rated for 1000 kVA are installed their foundations and structures should be so designed as to make possible the installation of two transformers of 1500 kVA each without much material modifications.

Reduction in transformer losses through proper load distribution The objective of the review of transformer system is to provide better quality of power to different load centers in the plant at high overall efficiency. In a medium and large industrial unit, there are number of transformers feeding power to the loads in the plant. These distribution transformers are sometimes not optimally loaded and there exists energy saving opportunity by shifting the load from overloaded transformer to the underloaded one.

8.2.4 Guidelines on selection of Electrical Motors

Motors shall comply with the following:

121 Phase 2 Report on Environmental Building Regulations and Guidelines framed fro Bangalore City

1. All permanently wired polyphase motors of 0.375 kW or more serving the building and expected to operate more than1500 hours per year and all permanently wired poly phase motors of 50 kW or more serving the building and expected to operate more than 500 hours per year shall have a minimum acceptable nominal full load motor efficiency not less than IS 12615 for Energy Efficient motors. The technical features and benefits of Energy Efficient motors are listed below:

• High efficiency motors are usually manufactured from materials, which incur lower energy losses compared with standard motors. More care is taken with the design and geometry of the motor construction. The high efficiency motors have been improved in four areas: • Longer core lengths of low loss steel laminations to reduce flux densities and iron losses • Maximum utilization of the slots and generous conductor sizes in the stator and rotor to reduce copper losses • Careful selection of slot numbers and tooth/slot geometry to reduce stray losses • Less heat is produced by a more efficient motor so the cooling fan size is reduced. This leads to lower windage losses and therefore less waste power.

The advantages of usage of high efficiency motors are as follows:

• Optimum use of energy as operating losses are lower • Reduced magnetic loss resulting in cooler applications • Low life cycle cost • Robust design to take care of wider supply variations ( 10%) and ambient temperature up to 80°C • Efficiency figures remain constant up to 75% of the rated output and drop maximum by 1% at 50% rated output

2. Motors of horsepower differing from those listed in the table shall have efficiency grater than that of the next listed kW motor. 3. Motor horsepower ratings shall not exceed 20% of the calculated maximum load. 4. Motor nameplates shall list the nominal full load motor efficiencies and the full load power factor. 5. Motor users should insist on proper rewinding practices for rewound motors. If the proper rewinding practices cannot be assured, the damaged motor should be replaced with a new, efficient one rather than suffer the significant efficiency penalty associated with typical rewind practices. 6. Certificates shall be obtained and kept on record indicating the motor efficiency. Whenever a motor is rewound, appropriate measures shall be taken so that the core characteristic s of the motor is not lost due to thermal and mechanical stress during

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removal of damaged parts .After rewinding, a new efficiency test shall be performed and similar records shall be maintained. 7. Motors should be installed with soft start energy savers and Variable Speed drives based on the application required.

8.2.5 Guidelines on improvement of Power factor

Methods of improving Power factor 1. Streamlining of the process by improving the electrical performance of the plant. 2. Replacing induction motors by synchronous motors of equal rating wherever possible. 3. Replacement of under loaded motors with motors of lower rating. 4. Reduction of voltage of motors which are regularly under loaded. 5. Restricting no load operation of motors. 6. Improving motor repair quality. 7. Replacement or relocation of under loaded transformers. 8. Installation of Capacitors

Measurement of power factor • by a directreading for Power factor meter for an instantaneous value, or • a recording VAr meter, which allows a record over a period of time to be obtained. of current, voltage and power factor. Readings taken over an extended period provide a useful means of estimating an average value of power factor for an installation.

Necessity of having good power factor Power factor improvement allows the use of smaller transformers, switchgear and cables, etc. as well as reducing power losses and voltage drop in an installation.

A high power factor allows the optimization of the components of an installation. Overrating of certain equipment can be avoided, but to achieve the best results the correction should be effected as close to the individual equipment in the building possible.

Losses in cables are proportional to square of the current and Power factor improvement reduced the T & D losses.

By improving the power factor of a load supplied from a transformer, the current through the transformer will be reduced thereby allowing more loads to be added. In practice, it may be less expensive to improve the power factor, than to replace the transformer by a larger unit.

Power factor improvement by installing capacitors

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Power factor improvement by installing capacitors is the widely followed method. Capacitors can be significant energy savers, if they are properly applied. A capacitor bank is also a load albeit with very low loss (0.20.4 W/kVAr). So it should be disconnected when VAr support is not required. If a fuse blows on a large capacitor, an unbalanced voltage occurs along with resultant increases in system and motor losses. Therefore, the fuse integrity of capacitor banks should be closely monitored. A high harmonic content in the power supply has been known to cause either capacitor failure or unplanned operation of protective devices. Hence use of latest semi conductor devices with appropriate technology can prove beneficiary in the long run.

Capacitors should be installed across the terminals of motors. However, the capacitor value should not exceed the no load kVAr value of the motor. Table 3 gives the approximate value of capacitors that need to be connected for different rating of the motors.

Table 8.3: Recommended capacitor rating for direct connection to induction motors (To improve power factor to 0.95 or better)

Capacitor rating in KVAr when motor speed is Capacitor rating in KVAr when motor speed is Motor Motor 3000 1500 1000 750 600 500 3000 1500 1000 750 600 500 H.P. H.P. r.p.m. r.p.m r.p.m r.p.m r.p.m r.p.m r.p.m r.p.m r.p.m r.p.m r.p.m. r.p.m. 2.5 1 1 1.5 2 2.5 2.5 105 22 24 27 29 36 41 5 2 2 2.5 3.5 4 4 110 23 25 28 30 38 43 7.5 2.5 3 3.5 4.5 5 5.5 115 24 26 29 31 39 44 10 3 4 4.5 5.5 6 6.5 120 25 27 30 32 40 46 12.5 3.5 4.5 5 6.5 7.5 8 125 26 28 31 33 41 47 15 4 5 6 7.5 8.5 9 130 27 29 32 34 43 49 17.5 4.5 5.5 6.5 8 10 10.5 135 28 30 33 35 44 50 20 5 6 7 9 11 12 140 29 31 34 36 46 52 22.5 5.5 6.5 8 10 12 13 145 30 32 35 37 47 54 25 6 7 9 10.5 13 14.5 150 31 33 36 38 48 55 27.5 6.5 7.5 9.5 11.5 14 16 155 32 34 37 39 49 56 30 7 8 10 12 15 17 160 33 35 38 40 50 57 32.5 7.5 8.5 11 13 16 18 165 34 36 39 41 51 59 35 8 9 11.5 13.5 17 19 170 35 37 40 42 53 60 37.5 8.5 9.5 12 14 18 20 175 36 38 41 43 54 61 40 9 10 13 15 19 21 180 37 39 42 44 55 62 42.5 9.5 11 14 16 20 22 185 38 40 43 45 56 63 45 10 11.5 14.5 16.5 21 23 190 38 40 43 45 58 65 47.5 10.5 12 15 17 22 24 195 39 41 44 46 59 66 50 11 12.5 16 18 23 25 200 40 42 45 47 60 67 55 12 13.5 17 19 24 26 205 41 43 46 48 61 68 60 13 14..5 18 20 26 28 210 42 44 47 49 61 69 65 14 15.5 19 21 27 29 215 42 44 47 49 62 70 70 15 16.5 20 22 28 31 220 43 45 48 50 63 71 75 16 17 21 23 29 32 225 44 46 49 51 64 72 80 17 19 22 24 30 34 230 45 47 50 52 65 73

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Capacitor rating in KVAr when motor speed is Capacitor rating in KVAr when motor speed is Motor Motor 3000 1500 1000 750 600 500 3000 1500 1000 750 600 500 H.P. H.P. r.p.m. r.p.m r.p.m r.p.m r.p.m r.p.m r.p.m r.p.m r.p.m r.p.m r.p.m. r.p.m. 85 18 20 23 25 31 35 235 46 48 51 53 65 74 90 19 21 24 26 33 37 240 46 48 51 53 66 75 95 20 22 25 27 34 38 245 47 49 52 54 67 75 100 21 23 26 28 35 40 250 48 50 53 55 68 76 Note: The recommended capacitor rating given in the above table is only for guidance purpose. (The capacitor rating should correspond approximately to the apparent power of the motor on noload).

Another chart for calculating the capacitors required for improving the Power factor in a building is given in table 4.

Table 8.4: Multiplying factor for calculating the sizes of capacitor for power factor improvement Power facto r Size of capacitors in kVAr per kW of load for raising the power factor to of load before 0.80 0.85 0.90 0.91 0.92 0.93 0.94 0.95 0.96 0.97 0.98 0.99 Unity applying capacitors 0.45 1.230 1.360 1.501 1.532 1.561 1.592 1.626 1.659 1.695 1.737 1.784 1.846 1.988 0.46 1.179 1.309 1.446 1.473 1.502 1.533 1.567 1.600 1.636 1.677 1.725 1.786 1.929 0.47 1.130 1.260 1.397 1.425 1.454 1.485 1.519 1.552 1.588 1.629 1.677 1.758 1.881 0.48 1.076 1.206 1.343 1.370 1.400 1.430 1.464 1.497 1.534 1.575 1.623 1.684 1.826 0.49 1.030 1.160 1.297 1.326 1.355 1.386 1.420 1.453 1.489 1.530 1.578 1.639 1.782 0.50 0.982 1.112 1.248 1.276 1.303 1.337 1.369 1.403 1.441 1.481 1.529 1.590 1.732 0.51 0.936 1.066 1.202 1.230 1.257 1.291 1.323 1.357 1.395 1.435 1.483 1.544 1.686 0.52 0.894 1.024 1.160 1.188 1.215 1.249 1.281 1.315 1.353 1.393 1.441 1.502 1.644 0.53 0.850 0.980 1.116 1.144 1.171 1.205 1.237 1.271 1.309 1.349 1.397 1.458 1.600 0.54 0.809 0.939 1.075 1.103 1.130 1.164 1.196 1.230 1.268 1.308 1.356 1.417 1.559 0.55 0.769 0.899 1.035 1.063 1.090 1.124 1.156 1.190 1.228 1.268 1.316 1.377 1.519 0.56 0.730 0.860 0.996 1.024 1.051 1.085 1.117 1.151 1.189 1.229 1.277 1.338 1.480 0.57 0.692 0.822 0.958 0.986 1.013 1.047 1.079 1.113 1.151 1.191 1.239 1.300 1.442 0.58 0.655 0.785 0.921 0.949 0.976 1.010 1.042 1.076 1.114 1.154 1.202 1.263 1.405 0.59 0.618 0.748 0.884 0.912 0.939 0.973 1.005 1.039 1.077 1.117 1.165 1.226 1.368 0.60 0.584 0.714 0.849 0.878 0.905 0.939 0.971 1.005 1.043 1.083 1.131 1.192 1.334 0.61 0.549 0.679 0.815 0.843 0.870 0.904 0.936 0.970 1.008 1.048 1.096 1.157 1.299 0.62 0.515 0.645 0.781 0.809 0.836 0.870 0.902 0.936 0.974 1.014 1.062 1.123 1.265 0.63 0.483 0.613 0.749 0.777 0.804 0.838 0.870 0.904 0.942 0.982 1.030 1.091 1.233 0.64 0.450 0.580 0.716 0.744 0.771 0.805 0.837 0.871 0.909 0.949 0.997 1.058 1.200 0.65 0.419 0.549 0.685 0.713 0.740 0.774 0.806 0.840 0.878 0.918 0.966 1.027 1.169 0.66 0.388 0.518 0.654 0.682 0.709 0.743 0.775 0.809 0.847 0.887 0.935 0.996 1.138 0.67 0.358 0.488 0.624 0.652 0.679 0.713 0.745 0.779 0.817 0.857 0.905 0.966 1.108 0.68 0.329 0.459 0.595 0.623 0.650 0.684 0.716 0.750 0.788 0.828 0.876 0.937 1.079 0.69 0.299 0.429 0.565 0.593 0.620 0.654 0.686 0.720 0.758 0.798 0.840 0.907 1.049 0.70 0.270 0.400 0.536 0.564 0.591 0.625 0.657 0.691 0.729 0.769 0.811 0.878 1.020 0.71 0.242 0.372 0.508 0.536 0.563 0.597 0.629 0.663 0.701 0.741 0.783 0.850 0.992 0.72 0.213 0.343 0.479 0.507 0.534 0.568 0.600 0.634 0.672 0.712 0.754 0.821 0.963 0.73 0.186 0.316 0.452 0.480 0.570 0.541 0.573 0.607 0.645 0.685 0.727 0.794 0.936

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Power facto r Size of capacitors in kVAr per kW of load for raising the power factor to of load before 0.80 0.85 0.90 0.91 0.92 0.93 0.94 0.95 0.96 0.97 0.98 0.99 Unity applying capacitors 0.74 0.159 0.289 0.425 0.453 0.480 0.514 0.546 0.580 0.618 0.658 0.700 0.767 0.909 0.75 0.132 0.262 0.398 0.426 0.453 0.487 0.519 0.553 0.591 0.631 0.673 0.740 0.882 0.76 0.105 0.235 0.371 0.399 0.426 0.460 0.492 0.526 0.564 0.604 0.652 0.713 0.855 0.77 0.079 0.209 0.345 0.373 0.400 0.434 0.466 0.500 0.538 0.578 0.620 0.687 0.829 0.78 0.053 0.183 0.319 0.347 0.374 0.408 0.440 0.474 0.512 0.552 0.594 0.661 0.803 0.79 0.026 0.156 0.292 0.320 0.347 0.381 0.413 0.447 0.485 0.525 0.567 0.634 0.776 0.80 0.130 0.266 0.294 0.321 0.355 0.387 0.421 0.459 0.499 0.541 0.608 0.750 0.81 0.104 0.240 0.268 0.295 0.329 0.361 0.395 0.433 0.473 0.515 0.582 0.724 0.82 0.078 0.214 0.242 0.269 0.303 0.335 0.369 0.407 0.447 0.489 0.556 0.698 0.83 0.052 0.188 0.216 0.243 0.277 0.309 0.343 0.381 0.421 0.463 0.530 0.672 0.84 0.026 0.162 0.190 0.217 0.251 0.283 0.317 0.355 0.395 0.437 0.504 0.645 0.85 0.136 0.164 0.191 0.225 0.257 0.291 0.329 0.369 0.417 0.478 0.620 0.86 0.109 0.140 0.167 0.198 0.230 0.264 0.301 0.343 0.390 0.450 0.593 0.87 0.083 0.114 0.141 0.172 0.204 0.238 0.275 0.317 0.364 0.424 0.567 0.88 0.054 0.085 0.112 0.143 0.175 0.209 0.246 0.288 0.335 0.395 0.538 0.89 0.028 0.059 0.836 0.117 0.149 0.183 0.230 0.262 0.309 0.369 0.512 0.90 0.031 0.058 0.089 0.121 0.155 0.192 0.234 0.281 0.341 0.484 0.91 0.027 0.058 0.090 0.124 0.161 0.203 0.250 0.310 0.453 0.92 0.031 0.063 0.097 0.134 0.176 0.223 0.283 0.426 0.93 0.032 0.066 0.103 0.145 0.192 0.252 0.395 0.94 0.034 0.071 0.113 0.160 0.220 0.363 0.95 0.037 0.079 0.126 0.186 0.329 0.96 0.042 0.089 0.149 0.292 0.97 0.047 0.107 0.250 0.98 0.060 0.203 0.99 0.143 Example: Given 100 kW load to be improved from 0.77 to 0.95 Power Factor. Factor from table is 0.500. ∴ Capacitor required (kVAr) = 100 x 0.500 = 50 kVAr.

8.2.6. Guidelines on Check Metering and monitoring

Energy accounting, monitoring and control is the very first step to be observed in any of the energy conservation management. a. Energy Accounting Metering of the energy consumed by an establishment is necessary so that:

• Energy consumed by equipment can be analysed in detail and corrective methods can be opted for improving equipment performances • The consumption of active energy in the individual major equipment, shops, sections, and plant can be monitored and variation in energy consumption in relation to production levels can be analysed.

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• The above analysis helps in benchmarking to arrive at optimum specific energy consumption and reduce process irregularities • The production of reactive energy by the compensating units of the building may be monitored and corrective steps can be adopted • It helps in identifying the optimum usage of demand allocation, thereby improving the load factor • Any consumers supplied via the building substation may be charged. • Energy accounting for the corresponding sections (i.e. individual profit centre concept) can be initiated towards input cost analysis. • Energy accounting shall help in correlating the daily, fortnightly, monthly, or annual energy consumption index with indication of deviation from the benchmark or the set target. b. Monitoring and Control It is always the best practice to install energy meters, hour meters (time totalisers) on major equipment/systems (HVAC system, Compressed air system, Pumping system, etc.,) consuming significant amount of energy. This shall help in accounting energy consumption on a shiftwise basis, daily basis, monthwise and yearly basis. Corelation of these consumption patterns with the production details (shiftwise production, equipmentwise production) shall lead to identify energy saving opportunities.

The summation of all submeter energy consumption should be compared with the summation of main plant energy meter (check meter for grid energy meter) and the energy meters of the DG sets. Energy accounting error of about 34% ( accounting for cable and equipment losses)between the summed values of submetering, main plant check meter and DG set energy meter to that of grid energy meters is reasonable. Enormous percentage error in the readings recorded needs to be viewed seriously.

8.2.7 Guidelines on distribution system losses

The distribution losses in the system are mainly on account of the losses in the cables and bus bars. The parameters that affect the cable losses are mainly cable resistance, power factor and voltage levels.

Losses Inplant cable losses are in the range of 1% to 4 %. Table 5 gives cable loss for various sizes of aluminium conductors..

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Table 8.5: I2R Losses per Phase (in Watts) of Various Sizes (in mm2) of Aluminium Cables of 10 m Length in a 3 Phase System

Size (mm 2) 25 35 50 70 95 120 150 185 240 300

Amps

15 2.7 1.95 1.4 0.99 ------

30 10.8 7.8 5.8 4.0 ------

45 24.8 17.6 13.0 9.0 6.5 - - - - -

60 43.2 31.2 23.1 15.9 11.5 9.1 7.4 5.9 - -

75 - 48.8 36.1 24.9 18.0 14.2 11.6 9.2 7.0 5.6

90 - - 51.9 35.9 25.9 20.5 16.7 13.3 10.1 8.1

105 - - 70.7 48.8 35.3 27.9 22.7 18.1 13.8 11.0

120 - - - 63.8 46.1 36.4 29.7 23.6 18.0 14.4

135 - - - 80.7 58.3 46.1 37.5 29.9 22.8 18.2

150 - - - - 70.0 56.9 46.4 36.9 28.1 22.5

165 - - - - 87.1 68.9 56.1 44.6 34.0 27.2

180 - - - - - 82.0 66.7 53.1 40.5 32.4

195 ------78.3 62.4 47.5 38.0

210 ------90.8 72.3 55.1 44.1

225 ------83.0 63.3 50.0

240 ------94.5 72.0 57.6

255 ------81.3 65.0

270 ------91.1 72.9

285 ------101.1 81.2

300 ------112.5 90.0

315 ------99.2

330 ------108.9

345 ------119.0

Loss Reduction Power losses in lines depend upon the resistance of the lines and the current carried. The resistance of lines may be considered constant. Then it follows that the only way to reduce the loss of power is to reduce the current. The current may be reduced by using as many reserve lines as possible. Dual lines should be connected in parallel for a more economical operation. Cable laying should be done strictly in accordance with carefully and systematically planned schedule. Drawing of this should be available at site and should be preserved at substations. All cable ends should be suitably labelled to facilitate easy identification. In all control cables adequate number of spare cores should be included. For cables, use IS:12551958, IS:962 1965 and IS:30431966 standards.

8.2.8 Guidelines on Power back up systems

A. DG Sets

With the rampant power shortage, poor power quality, disturbances, increased energy costs, as seen in the present SEB grid power distribution, industries are put to tremendous difficulties resulting in production losses, etc., This has lead to the need for captive power generation.

Industries/ buildings have several advantages in going for Captive Generating sets. Captive power generation offers the following advantages: 1. Continuous availability of power, free from utility power breakdown and grid disturbances, etc., leading to better productivity, less interruptions in process restart etc., 2. Good power system control obtained when operated in parallel with the utility supply system 3. Possibility of heat and electrical energy generation (Cogeneration) resulting in energy conservation and reduced energy cost, 4. Excess electrical energy generation can be supplied to the utility grid and earning income/ wheeling charges.

Selection of Captive Generation Equipment Based on the energy requirements, availability of fuels, availability and reliability of grid power at the plant location, industries should take up a detailed and careful study to decide the type of generating equipment, its rating and other specifications. Different modes of operating the Captive generation units are defined based on IEEE standard 446.

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Following modes of operation may be considered: • Standby Power supply Mode (Emergency Power Supply): Captive power generation set utilised in this mode shall meet the plant part load or total load requirement during the failure of utility power supply (Grid supply system). • Peak Loading Mode (Peak Lopping/Peak Shaving):

The captive power generation units are chosen to come into operation during peak load periods to supplement the utility supply (Grid supply) to limit the peak demand drawn from utility and thereby saving the electricity cost paid towards maximum peak demand.

• Base Load Mode (Primary Supply Mode):

This mode of operation is required in locations where there is no utility power supply or the utility supply is highly unreliable with frequent outages. A part or whole of the plant load is supplied on a continuous basis in this mode of operation. This mode of operation can also be termed as Total Energy mode. Industries where the requirement of heat and cooling water supply, apart from electricity opt for this mode of operation in the initial design stages.

The specific energy generation ( SEGR) of the DG sets varies with size and loading on the DG sets. A SEGR of 4 kWh/l is said to be an efficient design.

B. UPS/ Inverters An uninterruptible power supply, also uninterruptible power source, UPS or battery backup, is an electrical apparatus that provides emergency power to a load when the input power source, typically the utility mains , fails. A UPS differs from an auxiliary or emergency power system or standby generator in that it will provide instantaneous or nearinstantaneous protection from input power interruptions by means of one or more attached batteries and associated electronic circuitry. The onbattery runtime of most uninterruptible power sources is relatively short—5–15 minutes being typical for smaller units—but sufficient to allow time to bring an auxiliary power source on line, or to properly shut down the protected equipment. While not limited to protecting any particular type of equipment, a UPS is typically used to protect computers , data centers , telecommunication equipment or other electrical equipment where an unexpected power disruption could cause injuries, fatalities, serious business disruption and/or data loss. UPS units range in size from units designed to protect a single computer without a video monitor (around 200 VA rating ) to large units powering entire data centers, buildings. The efficiency level of the inverters varies from 92 95 % based on the capacity.

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8.2.9 Guidelines on Power Quality A Voltage Range, and Tolerance The voltage ranges in which the AC installations can be classified (as per IS: 12360 1988), according to their normal voltage for earthed and not effectively earthed systems, and the tolerances on declared voltages are given below in Table 6.

Table 8.6: Voltage Ranges in AC Installations Ranges LinetoLine rms. Standard Nominal Tolerance on Voltage adopted Values A.C. System Declared for the system Voltages Voltage I 50 V < u < 1000 V Three phase 415 V ± 6 % Distribution system Single phase 240 V II A 1 kV < u < 52 kV 3.3, 6.6, 11, 33 kV + 6 % & 9% Subtransmission II B 52 kV < u < 300 kV 66, 132, 220 kV ± 12.5 % Transmission III C U > 300 kV 400 kV ± 12.5 % Transmission u = Nominal voltage of the installation

The primary subtransmission voltage is 33 kV (in a few states, it is 66 kV). The 33 kV network is extended from 220 / 132 / 33 kV substations. The secondary subtransmission voltage is standardised at 11 kV. The lowtension voltage is either 415 V or 240 V, supplied to consumers.

B. Phase Voltage Imbalance in a Three Phase System Most utilities adopt a threephase, fourwire, groundedstar primary distribution system, so that singlephase distribution transformers can be connected directly to supply lines to cater to singlephase loads, such as residences and street lights. Variations in singlephase load distribution cause the currents in the threephase system to vary, producing different voltage drops and causing the phase voltage to become unbalanced.

Phase to phase voltage imbalances by even 2.5 % of the nominal voltage can reduce motor efficiency up to 10 %. This causes excessive heating due to the high negative sequence current. Imbalance of more than 5 % should therefore not be permitted.

Perfect balance can never be maintained since loads continuously change. Blown fuses on three phase capacitor banks also unbalance the load and cause phase voltage imbalance.

Proper balancing of singlephase loads on the three phases on both branch circuits and feeders is necessary to keep the load and corresponding phasevoltage imbalance within reasonable.

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C. Effects of Phase Voltage Imbalance Unequal loads on individual phases, negative and zero phase sequence components cause overheating of transformers, cables, conductors and motors thus increasing the losses and motor malfunction. The limit of negative phase sequence as per 1EC341 is 2% of the voltage.

When unbalanced phase voltages are applied to three phase motors, additional negative sequence currents circulate in the motor, increasing heat losses in the rotor. The most severe condition occurs when one phase is open and the motor runs on singlephase power.

In general, singlephase loads should not be connected to three phase circuits supplying equipment sensitive to phasevoltage imbalance. A separate circuit should be used to supply such equipment.

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GUIDELINE 9: Perform mandatory energy audit for existing commercial buildings with connected load of cases of 500 kW or 600 KVA and apply energy conservation measures to reduce energy consumption in existing commercial/institutional buildings

9.1 Guideline:

Energy audit should be carried out in all commercial/institutional buildings that have connected load more than 500kW or 600 kVa.

Energy performance indices should be derived for audited buildings and evaluated vis a vis Bureau of Energy Efficiency star rating (note: presently the BEE does not have EPI for rating of office buildings in temperate zone ;however it is under development; BEE star rating band is available for BPO buildings only)

Target should be set to achieve a minimum of 3 star rating by applying energy conservation measures (as and when developed).

9.1.1 Mandatory requirement The state utilities should be empowered to enforce the above. This cannot be included in the building byelaw.

9.2 Guidance Notes

Energy audits can be considered as the first step towards understanding how energy is being used in a given facility. Energy Audit indicates the ways in which different forms of energy are being used and quantify energy use according to discrete functions. Energy audits do not provide the final answer to the problem. It identifies where the potential for improvement lies, and therefore, where energy management efforts must be directed. Also, energy audit seeks to prioritize the energy uses according to the greatest to least cost effective opportunities for energy savings.

The following are the key steps for carrying out energy audit of a building

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9.3 Energy demand and Consumption

Energy consumption: The different sources of energy used in the building have to be identified with the help of facility people.

Step 1 -Data Collection Energy Bill: The Format in which energy bill needs to be collected and compiled is given below in the table 1.

Table 9.1: Building energy consumption

Building Energy Consumption

Sanctioned demand KVA Monthly Energy Consumption Pattern Cost kW KV P k Demand Total Month h A F W Energy Charges Charges Cost January February March April May June July August September October November December

Fuel Bill: In case DG is also installed then monthly energy generated by DG and the cost of fuel has to be collected for an year.

Total Area: The total built up area of the building needs to be collected.

Step 2 -Analysis:

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Energy performance Index (EPI): Energy performance index is a measuring tool to evaluate the performance of the building in terms of the total energy consumption and the total built up area. It is calculated by dividing the total energy consumption for a year and total built up area. The unit’s are kWH/annum/m2. Total Energy Consumption: Energy bill + fuel bill Total built up area: m2 Energy Performance index: kWh/ annum/m2 The table given below should be used to demonstrate the comparison of actual EPI with BEE recommended EPI for various buildings:

Table 9.2: EPI Comparison

EPI Comparison Parameter Actual EPI BEE recommended (kWh/annum/ EPI (kWH/annum/m 2) m2) Energy Performan ce Index

The above table gives the star rating index for BPO buildings in Bangalore . for other buildings, the index is under development.

Specific energy generation ratio: It indicates the no. of units (kWh) produced in one litre of fuel. The units are kWh/litre.

Step 3- Observation and Recommendation • Comment on the Energy Performance of the building. • Comment on DG performance • Comment on Tariff Rate

Step 4- Energy Conservation Measures

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Usage of efficient lighting system, HVAC system and other energy efficient products in order to reduce the building energy consumption and reducing the EPI within the recommended limit.

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9.4 Audit of individual systems

9.4.1 Electrical system

Step 1 -Data Collection

Information on the main source of electricity for the building and its single line diagram has to be collected. The transformer design details needs to be collected and compiled in the format given below in the table.

Table 9.3: Transformer rated parameters Transformer rated details Parameters Transformer Make Rated KVA High side Voltage Low Side Voltage Type of Cooling Frequency Year of Manufacturing

The motor design details needs to be collected and compiled in the format given below in the table.

Table 9.4: Motor rated parameters Motor Rated details Motor Description Voltage Current Power Actual factor KW Chilled water pump 1 Chilled water pump 2 Condenser water pump 1 Condenser water pump 3 CT Fan 1 CT Fan 2 AHU Motors and others

Step2-Measurement Building load profile: Building load profile has to be analysed for a single day at the main incomer of the building with the help of power analyser. The parameters that are needed to be analysed are voltage, power factor, frequency and current.

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Motor performance: Motor load test has to be carried out to find out their loading percentage. Electrical parameters like voltage (V), current (I), power factor (PF), and input electrical energy (kW) has to be measured with the help of tong tester

Table 9.5: Motor measured parameters Motor Percentage Loading Actual Percentage loading Motor Description KW Rated KW (%) Chilled water pump 1 Chilled water pump 2 Condenser water pump 1 Condenser water pump 3 CT Fan –1 CT Fan –2 AHU Motors

Transformer no load test: Transformer no load test has to be carried out on to find out their loading percentage. Electrical parameters like voltage (V), current (I), power factor (PF), and input electrical energy (kW) has to be measured with the help of tong tester

Step 3 -Analysis:

Motor loading: Based on the data collected during motor performance test which is given in table 5 the motor loading percentage has to be estimated in the format which is given the table 6.

Table 9.6: Motor loading (%) for the motors

Motor Percentage Loading Actual Rated Percentage loading Motor Description KW KW (%) Chilled water pump 1 Chilled water pump 2 Condenser water pump 1 Condenser water pump 3 CT Fan –1 CT Fan –2 AHU Motors

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Step 4- Observation and Recommendation • Comment on the power factor. • Comment on the motor loading percentage. • Comment on the transformer losses. • Voltage imbalance among the three phases.

Step 5- Energy Conservation Measures: • The power factor can be maintained above 0.95 by installing automatic power factor correction relay. • Motor loading above than 70% can be avoided by properly sizing the motor and by optimising the load on the motor. • Identified motors with less than 50 % loading, 50 – 75 % loading, 75 – 100 % loading, over 100 % loading. • Balancing of load among three phases.

9.4.2 Lighting System

Lighting accounts for a significant portion of the energy use in commercial buildings. In office buildings, for instance, 30% to 50% of the electricity consumption is used to provide lighting. In addition, heat generated by lighting contributes to the thermal load to be removed by the cooling equipment. Energy retrofits of lighting equipment are typically very costeffective, with payback periods of less than 2 years in most applications.

Step 1 -Data Collection Lighting Source: The details of the lighting source which include the wattage type pf lamp and inventory of lamp needs to be collected. The floor wise inventory of Lighting fixture, wattage and its type needs to be collected.

Table 9.7: Details of lighting source Lighting Source Details Total number of Item Wattage lamps Compact Fluorescent lamp (CFL) Compact Fluorescent lamp (CFL) Compact Fluorescent lamp (CFL) Fluorescent tube lamp (FTL T8) Decorative Down lighter Down lighter Others

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Table 9.8: Lighting fixtures and lamps Details of lighting fixtures and lamps Sl. Type of Type of No. of Total Load Area No. Floor Location lamp luminaries lamp (W) (m2) 1 2 3 4 5 6

Step 2- Measurement Illumination level: During the Energy audit, the illumination level has to be measured with the help of digital lux meter. The format in which the illumination level needs to collected and complied is given below in table.

Table 9.9: Illumination levels details area wise Area wise illumination level details S No. Area Average lighting level (lux) 1 Office area_enclosed 2 Ofice area_open plan 3 Corridor 4 Restroom 5 Conference 6 Reception 7 Library 8 Others

Lighting Power Density (LPD): It is the maximum lighting power per unit area of a building. It is calculated by dividing lighting load (W) for a specified region of the building by the area of that specified region. During the Energy audit, the lighting load needs to be calculated across different areas of the buildings which is listed in table 8. On the basis of that collected data LPD is calculated and is given in the table 10:

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Table 9.10: Lighting power density area wise Area wise lighting power density S No. Area Average LPD (W/m2) 1 Office area_enclosed 2 Ofice area_open plan 3 Corridor 4 Restroom 5 Conference 6 Reception 7 Library 8 Other areas

Step 3 -Analysis: Estimated lighting consumption: The lighting consumption for a year needs to be compiled in the following format. The consumption can be taken from the log books which are generally maintained by the facility in charge. The consumption gives an estimation of the contribution of lighting to the building consumption

Table 9.11: Monthly Lighting Consumption

Monthly lighting consumption Months Load (kW) Total Consumption

January

February

March

April May June July Augst September October November December Total

Illumination level: The table 12 given below shows the comparison of illumination level inside the building with NBC (National building code 2005) recommended illumination level

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Table 9.12: Illumination level comparison

Illumination level comparison Area Average lighting level (lux) NBC Recommended

Office area enclosed 300500 Ofice area open plan 300500 Corridor 50100150 Restroom 100150200 Conference 300500 Reception 200300500 Library 200300500

For other areas kindly refer national building code 2005

Lighting power Density (LPD): It is defined as the ratio of total operating load in a particular area to the built up area of that particular area. The units are W/m2. The table given below shows the comparison of ECBC recommended value with the actual LPD.

Table 9.13: LPD comparison

LPD Comparison Area Average LPD ECBC

(W/m2) Recommended Office area_enclosed 11.8 Ofice area_open plan 11.8 Corridor 5.4 Restroom 9.7 Conference 14 Reception 12.9

Library 11.8

For LPD at other areas kindly refer ECBC 2007

Over all Lighting power Density (LPD): It is defined as the ratio of total operating load in a building to the built up area. The units are W/m2. The table given below shows the comparison of ECBC recommended value with the actual LPD.

Table 14: Overall LPD Comparisons Overall LPD Comparison Area Average LPD ECBC (W/m2) Recommended Over all 11.8

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Building

Step 4- Observation and Recommendation:

• Comment on Visual Comfort in comparison with NBC recommended. • Comment on LPD in comparison with ECBC recommendation.

Step 5- Energy Conservation Measures: • The visual comfort can achieve by selecting proper fixture, integrating day lighting with artificial lighting. • The recommended LPD can be achieved by selecting proper luminaries and lamps. According to the Energy Conservation Building Code following lighting controls are mandatory

Automatic Lighting shutoff • Interior lighting systems in buildings larger than 500m2 shall be equiped with an automatic control device. In these buildings, all office areas less than 30m2 enclosed by wall and roof partitions, meeting rooms, conference rooms, storage spaces shall be equipped with occupancy sensors. • a) other spaces, the automatic control device shall function on either: • A scheduled basis at specific programmed times. An independent program schedule shall be provided for areas no more than 2,500m2 and not more than one floor ; or, • Occupancy sensors that shall switch OFF the lights within 30 minutes of an occupant leaving the space.. There should be a manual switch capable to switch ON the lights when the space is occupied. According to the Energy Conservation Building Code following lighting controls are mandatory b) Space Control

Each space enclosed by ceiling and wall partitions, shall have at least one control device to control the general ligting within the space. The control devices should be activated either manually or automatically by sensing an occupant. Each control device shall:

• Control a maximum of 250m2 inside a space less than or equal to 1,000m2 and a maximum of 1,000m2 for a space greater than 1,000 m2. • It should be able to override the shutoff control. • The control device should be readily accessible and located so that the occupants can see the control.

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9.4.3 HVAC system

HVAC accounts for a significant portion of the energy use in commercial buildings. In office buildings, for instance, 60% to 80% of the electricity consumption is used to provide HVAC

Step 1 -Data Collection

The detail layout of HVAC plant should be collected along with the design parameters of all the HVAC equipments. The table given below shows the format for data collection of the design parameters of HVAC equipments:

Table 9.15: HVAC rated parameters

HVAC Rated Parameters

Equipment type Chiller Make

Model

Type

Condenser type Rated capacity

Refrigerant used

Supply chilled water temperature

Entering condenser water temperature Rated KW

Fuel Used

No. of chillers installed

Equipment chilled water pumps Type

Capacity

Head

Rated motor kW

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No. of pumps installed

Equipment Condenser water pump Type

Capacity

Head

Rated motor kW No. of pumps installed

Equipment Cooling Tower

Capacity

Fan motor rating No. of CTs installed

Make

Chiller performance testing: The operating parameters of Chiller plant has to be monitored for one day. The supply chilled water temperature (SCHWT) and return chilled water temperature (RCHWT) have to be taken. Similarly the entering condenser water temperatures and leaving condenser water temperatures has to be taken. The chilled water flow and condenser water flow has to be established with the help flow measurement taken near chilled water pumps and condenser water pumps

Fig 1 Overview of Chiller Performance Test

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Pump performance testing: The operating parameters of all the pumps in all the pumping systems has to be measured. Heads has to be measured with the help of digital pressure meter, flows with the help of nonintrusive type flow meters. Electrical parameters has to be measured along with flow and head measurements

Fig 2 Overview of pump p erformance Test

AHU performance testing: Total filter area has to be measured and coil face area has to be calculated. The air velocity in individual AHUs has to be calculated with the help of digital air flow meter at AHU performance testing: Total filter area has to be measured and coil face area has to be calculated. The air velocity in individual AHUs has to be calculated with the help of digital air flow meter at different places and average air velocity near filter or coil was worked out. The supply and return air drybulb and wet bulb temperatures have to be measured to estimate the load on individual AHUs. Motor loading has to be measured with the help of digital power multimeter.

AHU performance testing: Total filter area has to be measured and coil face area has to be calculated. The air velocity in individual AHUs has to be calculated with the help of digital air flow meter at AHU performance testing: Total filter area has to be measured and coil face area has to be calculated. The air velocity in individual AHU has to be calculated with the help of digital air flow meter at different places and average air velocity near filter or coil was worked out. The supply and return air drybulb and wet bulb temperatures have to be

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measured to estimate the load on individual AHUs. Motor loading has to be measured with the help of digital power multimeter

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Fig 3 Overview of AHUI perfo rmanc e Test

Cooling tower performance testing: Temperature, RH has to be taken near the sump of cooling tower. Fan power has to be taken with the help of multimeter. Flow has to be taken at the condenser water line with the help of non intrusive type flow meter.

Fig 4 Overview of cooling tower test

Step 3 -Analysis:

Estimated HVAC consumption: Based on installed energy meters, recorded log book data, measured operating efficiencies of different equipment measured during field survey, and

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discussion made with the engineering and maintenance staff the energy consumed in AC system has to be estimated. The estimated energy consumption is given in the Table 16 below.

Table 9.16: Monthly estimated consumption Monthly Estimated HVAC Consumption CHW Cooling water pump and Months Chiller AHUs pump CT fan April May June July Augst September October November December January February

The estimated AC system consumption helps in analysing which equipment wise consumption of HVAC.

Performance evaluation of chiller: Based on the operating data collected, the specific power and the coefficient of performance of different plants at operating load have to be calculated. The complete analysis of chiller performance evaluation is summarized in Tables below.

Table 9.17: Performance evaluation for chiller

Performance Evaluation of Chiller Description Units Parameters Water side Chiller Leaving Chilled water temperature Deg. C Entering Chilled water temperature Deg. C Temp. Difference Deg. C Chilled water flow M3/hr Leaving Condenser water temperature Deg. C Entering Condenser water temperature Deg. C Temperature Difference Deg. C Input power KW Capacity TR KW/TR COP

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Performance Evaluation of Pumps: The table given below shows the format in which measured and actual operating data for pumps has to be compiled.

Table 9.18: Performance evaluation for pumps

Performance Evaluation for pumps

Actual Rated Actual Rated Rated Actual Flow Flow Head head Efficiency KW KW GPM GPM M M % CHW Primary Pump No1

CHW Primary

Pump No2

CDW No1

CDW No3

Performance evaluation of Performance Evaluation for Cooling Towers AHUs: The table given Parameters below shows the format in Air discharge area (ft 2) which measured and actual Air velocity (ft/min) operating data for AHUs has Air flow (CFM) to be compiled. Entering water temp (0 C) Table 9.19: Performance evaluation Leaving water temp (0 C) for Air Handling Units Ambient wet bulb temp (0 C) Range (0 C)

Wet bulb approach (0 F)

Effectiveness (%)

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Performance evaluation of cooling towers: Different measurements that have to be taken on the cooling towers are given in Table 20. The average cooling towers wet bulb approach that is defined as the difference of leaving water temperature and the ambient wet bulb temperature. The average thermal efficiency of cooling towers which is defined as the ratio of range to the sum of range and approach has to be calculated

Table 9.20 : Performance evaluation for Cooling Towers

Performance Evaluation for Air handling units AHU Actual Rated Actual Rated Location Capacity Capacity Capacity Capacity

Units CFM CFM TR TR Basement 1 First Floor 2 3 4 5 Second 6 Floor 7 8 9

Third 10 Floor 11 12 13

Cooling demand: It is defined as the ratio of total built up area of the total to the total cooling demand of the building. The units are ft2/TR. The table 21 given below shows the comparison of ASHRAE recommended value with the actual cooling demand.

Table 9.21: Cooling demand comparison

Cooling Demand Comparison Description Design Peak cooling demand ASHRAE recommended cooling demand (ft2/TR) (ft2/TR) Over all 250300 Building

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Thermal comfort: The table 22 given below shows the thermal comfort performance of the building, which is defined in terms of Temperature and Relative humidity, maintained inside the building. The table also shows the comparison with NBC recommended thermal comfort.

Table 9.22: Thermal comfort

Thermal Comfort Building Location Average Average NBC Recommended NBC recommended Relative humidity Temp. RH temperature deg C (%) 2426 5060 2426 5060

Step 4- Observation and Recommendation:

• Comment on Chilled water and condenser water pump efficiency • Comment on Cooling tower efficiency • Comment on Thermal comfort maintained in the building in comparison with NBC recommended. Comment on whether VFD is being installed on the secondary chilled water loop circuit and AHUs motors

Step 5- Energy Conservation Measures:

• Chilled water pumps and condenser water pumps shall be replaced by energy efficient pumps having efficiency of 60% and above • Cooling tower shall be replaced by energy efficient cooling tower. • Insulate all cold lines / vessels using economic insulation thickness to minimize heat gains; and choose appropriate (correct) insulation. • Ensure adequate quantity of chilled water and cooling water flows, avoid bypass flows by closing valves of idle equipment. • Minimize part load operations by matching loads and plant capacity on line; adopt VFD for varying process load. 9.5 Controls in the HVAC system recommended by Energy Conservation Building Code (ECBC)

1. All mechanical cooling and heating systems shall be controlled by a time clock that:

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• Can start and stop the system under different schedules for three different daytypes per week. • Is capable of retaining programming and time setting during loss of power for a period of at least 10 hours, and • Includes an accessible manual override that allows temporary operation of the system for up to 2 hours.

• All heating and cooling equipment shall be temperature controlled. The controls shall be capable of providing a temperature dead band of 3deg.C within which the supply of heating and cooling energy to the zone is shut off or reduced to a minimum. • All cooling towers and closed circuit fluid coolers shall have either two speed motors, pony motors, or variable speed drives controlling the fans. 9.6 Benefits

Energy Audit provides act as a tool that can be used to analyze building load profile, equipment efficiencies and the energy optimization scope for a building. It attempts to balance the total energy inputs with its use, and serves to identify all the energy streams in a facility. It quantifies energy usage according to its discrete functions.

The direct and indirect advantages of Energy audit are summarized as follows

• Tells you where you are, what you should focus on first and what environmental and cost benefits can be achieved. • Assessing the performance efficiency of utility systems & equipment. • Evaluating the present status in comparison with the standard specific consumption norms and set up a baseline which helps in comparing the current energy scenario ( includes HVAC, lighting and electrical system) with ECBC recommended • Targeting recurring savings of approximately 5% to 10% on Energy cost and with favorable payback period of usually less than a year. • Identifying, short term & long term measures for implementation. • Improving awareness of employees about energy conservation through proper training at all levels. • Increased comfort of building occupants • Reduced environmental impacts • By saving energy, industries can reduce the emission of green house gases (GHG) into the atmosphere

9.7 Glossary

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1. Lighting Power density (LPD): It is calculated by dividing the total lighting load in wattage with total area (m2). The units are W/m2. 2. Energy Performance Index: It is calculated as the ratio of total building energy consumption in a year to the total built up area. 3. Chiller Performance: It is calculated based on the formula given below:

• The refrigeration TR is assessed as TR = Q x Cp x (Ti – To) / 3024 • Where Q is mass flow rate of coolant in kg/hr • Cp is coolant specific heat in kCal /kg deg C • Ti is inlet, temperature of coolant to evaporator (chiller) in °C • To is outlet temperature of coolant from evaporator (chiller) in °C.

The above TR is also called as chiller tonnage. The specific power consumption kW/TR is a useful indicator of the performance of refrigeration system. By measuring refrigeration duty performed in TR and the kiloWatt inputs, kW/TR is used as a reference energy performance indicator.

1. Pump Performance: Pump efficiency can be calculated based on the formula given below:

Efficiency: hydraulic power/electrical input power Hydraulic power: Q (m3/s) x Total head, (hd – hs) (m) x ρ (kg/m3) x g (m/s2) / 1000 Where hd – discharge head, hs – suction head, ρ – density of the fluid, g – acceleration due to gravity

2. Cooling tower performance: cooling tower performance is calculated based on the formula given Efficiency: range/ (range + approach) Range: Difference between the cooling tower water inlet and outlet temperature. Approach: Difference between the cooling tower outlet cold water temperature and ambient wet bulb temperature.