İSTANBUL TECHNICAL UNIVERSITY INSTITUTE OF SCIENCE AND TECHNOLOGY TUBULAR LIGHT GUIDANCE SYSTEMS AS ADVANCED DAYLIGHTING STRATEGY M.Sc. Thesis by Öngüç ÖZGÜN, B. Arch. (502031734) Date of submission : 25 December 2006 Date of defence examination: 29 January 2007 Supervisor (Chairman): Assoc. Prof. Dr. Alpin KÖKNEL YENER Members of the Examining Committee Prof. Dr. A. Zerrin YILMAZ Prof. Dr. Ursula EICKER (S.A.S) JANUARY 2007 ACKNOWLEDGEMENTS I am indebted to the following people for their precious guidance, support and encouragement throughout my research. My supervisor, Assoc. Prof. Dr. Alpin K. YENER supervised the study on which this thesis is based and her learning, tact and moral support have constantly helped and guided me. Prof Dr. Ursula EICKER encouraged me to join the Erasmus program which lasted ten months in Stuttgart and helped me to improve myself through experience. She suggested me to compare an advanced daylighting system versus a conventional system considering their energy consumption. Dr. Alexander ROSEMANN and Dr. Aziz LAOUADI gave not only encouraging support replying my mails and suggesting solutions but also sending me invaluable documents. Dr. Sırrı AYDINLI advised me first time to study on light pipe systems in my thesis. I am grateful Assoc. Prof. Dr. Dilek ENARUN for her guidance on my decision to use a simulating a system installed in a simple office room rather than using an already present complex light pipe system in my analyses and evaluations. Prof. Dr. A. Zerrin YILMAZ has pointed at areas that need further investigation and made it possible for me to consider those parts as a future project in a more comprehensive study. Three particular thanks must end this list. One is to my family for their endless patience. The second is to my crony, I şıl ÖZCAN for helping me editing my thesis in English. And the last is, to my dearest partner, Fırat KES İM, for his amazing patience and unlimited support. December, 2006 Öngüç ÖZGÜN ii TABLE OF CONTENTS ABBREVIATIONS v LIST OF TABLES vı LIST OF FIGURES vıı LIST OF SYMBOLS ıx SUMMARY x ÖZET xı 1. INTRODUCTION 1 2. LIGHT TRANSPORTING SYSTEMS AS ADVANCED DAYLIGHTING STRATEGY 4 2.1. Introduction and Classification 4 2.2. Daylight Guidance Systems 6 2.2.1. Light guide ceilings 6 2.2.2. Optical fiber systems 7 2.2.3. Light pipes 12 2.2.3.1. Classification of light pipes 12 2.2.3.2. Specification of a light pipe system 17 2.2.3.3. Integration of light with artificial light sources 25 3. ARCHITECTURAL DESIGN PRINCIPLES OF LIGHT PIPES IN OFFICE BUILDINGS 28 3.1. General Principles of Office Lighting 28 3.1.1. Illumination 29 3.1.2. Luminance 30 3.1.3. Uniformity 33 3.1.4. Daylighting in Office Buildings 34 3.2. Integration of Light Pipes with Building Design 35 3.2.1. Geographical location 35 3.2.2. Integration with Space Planning 36 3.2.3. Integration with Environmental Strategy 37 3.2.4. Building Codes 38 3.2.5. Application to Existing Buildings 40 iii 4. PERFORMANCE EVALUATION OF TUBULAR LIGHT GUIDE SYSTEMS 42 4.1. Early Experiments and Methods 42 4.2. Recent Experiments and Methods 45 4.2.1. Evaluation with scaled models 47 4.2.2. Evaluation with simulation models 57 5. VALIDATION OF SKYVISION TOOL ON A TUBULAR LIGHT GUIDE SYSTEM INSTALLED IN OFFICE ROOM 64 5.1. Skyvision as a Simulation Tool 64 5.2. Simulation Process 65 5.2.1. Software inputs 65 5.2.1.1. General inputs 65 5.2.1.2. Specifying sky conditions 65 5.2.1.3. Defining the conventional skylights 68 5.2.1.4. Defining the tubular skylights 69 5.3. Calculation Engine 69 5.3.1. Sky models 69 5.3.2. Optics modules 71 5.3.3. Daylighting modules 71 5.4. Description of the Test Model and Simulation Methodology 71 5.4.1. Base Model (Light Pipe) 72 5.4.2. Reference Model 1 (Flat Skylight) 76 5.4.3. Reference Model 2 (Central Flat Skylight) 77 5.5. Software Outputs 78 5.5.1. Evaluation of the results 79 5.5.2. Optical characteristics of the system 80 5.5.3. Daylighting performance of the system 83 5.5.4. Annual energy performance of the system 85 5.6. Discussion 86 6. CONCLUSION AND FUTURE WORK 90 REFERENCES 94 APPENDICES 102 CURRICULUM VITAE 124 iv ABBREVIATIONS ASHRAE : American Society of Heating, Refrigerating and Air-Conditioning Engineers BBRI : Belgian Building Research Institute BSR : Bomin Solar Research CCD : Charge-Coupled Device CFD : Computer Fluid Dynamics CIBSE : The Chartered Institution of Building Services Engineers CIE : International Commission on Illumination DES : Daylight Energy Saving DF : Daylight Factor GC : Kodak Grey Card HDR : High Dynamic Range HLG : Hollow Light Guide IBUS : Institut für Bau, Umwelt, und Solarforschung IEA : International Energy Agency IESNA : The Illuminating Engineering Society of North America IR : Infra Red ISAR : Illuminated Surface Area Ratio LAT : Latitude LED : Light Emitting Diode LBNL : Lawrence Berkeley National Laboratory OLF : Optical Light Film PC : PolyCarbonate PMMA : PolyMethal MethAcrylate POE : Post Occupancy Evaluation RMSE : Root Mean Square Error SHGC : Solar Heat Gain Coefficient SOE : Secondary Optical Element TTE : Tube transmission efficiency UV : Ultra Violet VDT : Visual Display Terminal WC : Kodak White Card v LIST OF TABLES Page No Table 3.1 Minimum illumination levels determined by CIE……………….. 30 Table 4.1 Predicted performance of light pipes in Belgium………………... 48 Table 4.2 Spectral transmittance of light pipe materials …………………… 49 Table 4.3 Floor, ceiling, walls and furniture reflectances…………………. 52 Table 5.1 Light pipe optical characteristics from beam radiation…………... 81 Table 5.2 Light pipe optical characteristics from beam radiation…………... 81 Table 5.3 Light pipe optical characteristics from diffuse radiation………… 81 Table 5.4 Light pipe optical characteristics from diffuse radiation………… 82 Table 5.5 Light pipe optical characteristics. Variation with incidence angle. 82 Table 5.6 Daylighting performance of the system. Average daylight factors 83 Table 5.7 Daylighting performance of the system. Average daylight factors 84 Table 5.8 Daylighting performance of the system. Total illuminance levels. 84 Table 5.9 Daylighting performance of the system. Total illuminance levels. 85 Table 5.10 Annual energy performance of the system………………………. 85 Table 5.11 Monthly average outdoor and indoor illuminance levels………… 86 Table 5.12 Annual energy performance of 3 systems………………………... 87 Table A.1 Flat Skylight optical characteristics incident from beam radiation. 103 Table A.2 Flat Skylight optical characteristics incident from beam radiation. 104 Table A.3 Flat Skylight optical characteristics (diffuse radiation)………….. 104 Table A.4 Flat Skylight optical characteristics (diffuse radiation)………….. 104 Table A.5 Average Daylight Factors ……………………………………….. 105 Table A.6 Average Daylight Factors………………………………………... 105 Table A.7 Total Illuminance Levels on inner surfaces……………………… 105 Table A.8 Total Illuminance Levels on inner surfaces……………………… 106 Table A.9 Monthly average outdoor and indoor illuminance levels………… 106 Table A.10 Central Flat Skylight optical characteristics (beam radiation)…… 107 Table A.11 Central Flat Skylight optical characteristics (beam radiation)…… 107 Table A.12 Central Flat Skylight optical characteristics (diffuse radiation)…. 107 Table A.13 Central Flat Skylight optical characteristics (diffuse radiation)…. 108 Table A.14 Average Daylight Factors on inner surfaces……………………... 108 Table A.15 Average Daylight Factors on inner surfaces……………………... 108 Table A.16 Total Illuminance Levels on inner surfaces……………………… 109 Table A.17 Daylighting performance of the system. Total Illuminance Levels 109 on inner surfaces…………………………………………………. vi LIST OF FIGURES Page No Figure 2.1 : Prototype of the transport and diffuser unit................................ 7 Figure 2.2 : The sunlight collector ................................................................. 8 Figure 2.3 : The lenses in collector and input-output ends............................. 9 Figure 2.4 : An overview of Hybrid Lighting system ................................... 10 Figure 2.5 : A Solux collector ....................................................................... 11 Figure 2.6 : Vertical Section of end-lighting light pipe.................................. 13 Figure 2.7 : Heliostat and squared light pipe.................................................. 15 Figure 2.8 : Light guide walls section...............................................................15 Figure 2.9 : Light pipe mechanism in Berlin Technical University.................17 Figure 2.10 : Different types of light pipes...................................................... 18 Figure 2.11 : Heliostat ..................................................................................... 19 Figure 2.12 : The section of prismatic light pipe.............................................. 20 Figure 2.13 : The microstructure of optical light film...................................... 21 Figure 2.14 : Light bounces between inner walls of the tube........................... 22 Figure 2.15 : Comparison between external and internal illuminance............. 23 Figure 2.16 : The diffusers............................................................................... 24 Figure 2.17 : Diffuser illumination arcs illumination charts..............................24 Figure 2.18 : The light pipe mechanism in Borusan Headquarters................... 26 Figure 2.19 : Light pipes for both artificial and natural lighting...................... 26 Figure 2.20 : Illumination of Callahan Tunnel………………………………. 27 Figure 3.1