| Lund University Lund University, with eight faculties and a number of research centers and specialized institutes, is the largest establishment for research and higher education in Scandinavia. The main part of the University is situated in the small city of Lund which has about 112 000 inhabitants. A number of departments for research and education are, however, located in Malmö and Helsingborg. Lund University was founded in 1666 and has today a total staff of 6 000 employees and 47 000 students attending 280 degree programs and 2 300 subject courses offered by 63 departments. Master Program in Energy-efficient and Environmental Building Design This international program provides knowledge, skills and competencies within the area of energy-efficient and environmental building design in cold climates. The goal is to train highly skilled professionals, who will significantly contribute to and influence the design, building or renovation of energy-efficient buildings, taking into consideration the architecture and environment, the inhabitants’ behavior and needs, their health and comfort as well as the overall economy. The degree project is the final part of the master program leading to a Master of Science (120 credits) in Energy-efficient and Environmental Buildings. Examiner: Maria Wall Supervisor: Marie-Claude Dubois Secondary Supervisor: Jouri Kanters Keywords: Solar lighting, Simulation, Daylight, Fiber optics, LEED, Illuminance, Glare. Thesis: EEBD–14/01 Program Scripting & Evaluating Fiber Optic Daylighting Systems Abstract Keeping in mind the positive health- and emotional effects on hum an beings, using daylighting over electric lighting, this thesis demonstrates the use of an innovative daylighting technology, fiber optics. The objective of using the fiber optic daylighting system is to transfer daylight from exterior to interior into rooms with small or no w indows. In this project, a simulation script was created for the SP4 fiber optic daylighting system from the company Parans Solar Lighting AB. The script was programmed in Grasshopper, using Rhinoceros as an interface and a detailed study guide completed. The environmental certification system Leadership in Energy and Environmental Design (LEED) was chosen as a guideline to meet certain credit points for the horizontal illuminance desired in a specific area. The fiber optic daylighting system was installed in the laboratory of Lund University, Energy and Building Design. Real measurements were taken on a sunny day, for the reason that the system solely works with direct illuminance. A case study was then carried out to evaluate the accuracy and functionality of the script. In a second phase, a parametric study was performed where the climate was varied. Four countries were selected using a solar map, with ratios of diffuse to direct irradiation. The choice of cities was influenced by where the company Parans has most of their clients. Additionally, one Daylight Autonomy simulation was completed. Finally, a d etailed glare risk assessment was performed to evaluate the possible visual discomfort of the daylighting system. The script created is useful to save time when planning the systems’ use and can be adjusted to different locations and room types. Furthermore, it could be used to help to optimize the installation and to estimate the optimum amount of cables used. 2 Program Scripting & Evaluating Fiber Optic Daylighting Systems Acknowledgements This thesis was formed as a p art of the Master Program in Energy-efficient and Environmental Building Design. We are especially grateful to our supervisor and daylighting expert Marie-Claude Dubois who showed interest, helped and supported us exceptionally throughout this work. She helped us keep a positive attitude during the development of the thesis project and encouraged us in every way she saw possible. We are profoundly thankful for our secondary supervisor Jouri Kanters, whose kind presence and excellence in Grasshopper computer programming technology came in good use when assisting us developing the fiber optic simulation script. We are grateful to Maria Wall for supporting us and providing important information during the study. We thank Karl Richard Nilsson from Parans Solar Lighting AB for his countless support and provision of the project, and Maria Nordberg from White Architects for providing this project. Additionally, we are thankful for the financial support from Parans who made it possible for us to go on an unforgettable study visit to the United States to meet with two board members of the U.S. Green Building Council. We would like to thank Rob Hink, principal and senior vice president of the LEED faculty and Brian Lomel, principal and sustainability consultant for LEED, for taking time to interview with us. Furthermore, we would like to thank Campus Vänner for their funding. We wish to acknowledge the help and support from Henrik Davidsson, Niko Gentile and Ricardo Bernardo. We thank our good friend and classmate Alejandro Pacheco Diéguez for his help and encouragement. We express great gratitude to everyone else at the department, who brightened our days with great support and interesting conversations. Special thanks to our partners, family and close friends for all their moral support, true interest and believing in us. Finally, we are truly grateful to the Eliasson foundation for sponsoring the program of Energy-efficient and Environmental Building Design. 3 Program Scripting & Evaluating Fiber Optic Daylighting Systems Table of Content Abstract ............................................................................................................. 2 Acknowledgements ........................................................................................... 3 Terminology ...................................................................................................... 7 Acronyms / Abbreviations 7 Terms and Definitions ....................................................................................... 8 Photometric Units 8 Luminous Flux 9 Illuminance 9 Luminance 9 Luminous Efficacy 10 Daylight Autonomy 10 RGB Values vs. Wavelengths 10 Transmittance vs. Transmissivity 10 Glare 11 Disability Glare 11 Discomfort Glare 11 Daylight Glare Probability 11 Daylight Glare Index 11 Window to Floor Ratio (WFR) 12 Daylight Factor 12 High Dynamic Range (HDR) Image 12 Structure and Short Summary of the Thesis .................................................... 13 1 Introduction ............................................................................................. 15 1.1 Background and Problem Motivation 16 1.1.1 Parans Lighting System 16 1.1.2 Environmental Certification Systems 18 1.1.3 Environmental Certification System LEED – Daylight Part 19 1.1.4 Simulation Programs Rhinoceros and Grasshopper 20 1.1.5 Problem Motivation 21 1.2 Overall aim and concrete and verifiable goals 21 1.3 Scope 22 2 Literature Review .................................................................................... 23 2.1 Studies about Daylighting Technologies 23 2.2 Studies about Benefits of Daylight (Health and Performance) 24 2.3 Earlier Studies about Energy Savings, using Fiber Optic Lighting Systems 24 2.4 Earlier Studies about Risk of Glare 25 3 Methodology / Model .............................................................................. 26 3.1 Fiber Optic Lighting System 26 4 Program Scripting & Evaluating Fiber Optic Daylighting Systems 3.2 Creating a new Simulation Script 30 3.2.1 Geometry in Grasshopper 30 3.2.2 Material Properties 31 3.2.3 Simulations in Grasshopper 32 3.2.4 Output in Rhinoceros 34 3.3 Case Study for Verification 34 3.3.1 Calculation of Surface Reflectances 36 3.3.2 Simulation Script 37 3.4 Parametric Study 38 3.4.1 Daylight Autonomy 40 3.5 Glare Assessment 40 3.5.1 Assessment of the Real Scene 41 3.5.2 Assessment of the Modelled Scene 43 4 Results ..................................................................................................... 44 4.1 Simulation Script 44 4.2 Measurements and validation 45 4.2.1 Weather Data 45 4.2.2 Real Measurements vs. Simulations 46 4.3 Parametric Study 47 4.3.1 Average Illuminance vs. Percentage of Illuminance between 300 and 3000 lux. 47 4.3.2 Optimum placement for San Francisco 48 4.3.3 Optimum placement for Copenhagen 49 4.3.4 Comparison of locations 50 4.4 Daylight Autonomy 51 4.5 Glare Assessment 51 4.5.1 Assessment of the Real Scene 51 4.5.2 Assessment of the Modelled Scene 54 4.6 Summary of Results 57 4.6.1 Simulation Script 57 4.6.2 Measurements and validation 57 4.6.3 Parametric Study 57 4.6.4 Daylight Autonomy 57 4.6.5 Glare Assessment 57 5 Discussion ............................................................................................... 58 5.1 Simulation Script 58 5.2 Measurements and validation 58 5.3 Parametric Study 59 5.3.1 Daylight Autonomy 59 5.4 Daylight 60 5.5 Glare Assessment 60 6 Conclusion ............................................................................................... 61 5 Program Scripting & Evaluating Fiber Optic Daylighting Systems 6.1 Limitations 62 6.1.1 Limitations of the Simulation Script 62 6.1.2 Limitations Related to Measurements and Validation 62 6.1.3 Limitations of glare study 63 6.2 Further Development and future work 63 References ....................................................................................................... 65 Appendix A: Calculation of Transmissivity .................................................... 69 Appendix B: User Guide ................................................................................