Building a comprehensive dataset for the validation of daylight simulation software, using complex “real architecture” Jake Osborne Building a comprehensive dataset for the validation of daylight simulation software, using complex “real architecture” By Jake Osborne A thesis submitted to the School of Architecture, Victoria University of Wellington in fulfilment of the requirements for the degree of Master of Building Science Victoria University of Wellington September 2012 I Preface This thesis was submitted in fulfilment of the requirements of the Master of Building Science degree at Victoria University of Wellington School of Architecture and Design in 2012. Author: Jake Osborne School of Architecture and Design Victoria University of Wellington [email protected] +64-21-153-4266 Research Supervisor: Michael Donn Director Centre for Building Performance Research School of Architecture and Design Victoria University of Wellington [email protected] Victoria University +64-4-463-6221 work PO Box 600 +64-21-611-280 mobile Wellington +64-4-463-6204 work fax New Zealand +64-21-611-594 mobile fax Jake Osborne I II Abstract This research focused on building a comprehensive dataset for use in validation studies of daylight simulation software. The aim of the set is to add to existing validation data to better cover a wide range of complexities and weather conditions. This will allow for not only the validation of simulation software, but the comparison of multiple simulators in their general strengths and weaknesses as well as feasibility for early ‘sketch’ design stages and complete building simulations. The set can also aid in the creation of valid simulation parameter starting points for designers. The research examined the current ‘gold standard’ validation dataset from the BRE-IDMP, and found that while it provides excellent validation opportunities for simulators that can support its detailed patch-based sky model; an equally high quality dataset is needed for simulators that support more simplified skies. This is essential as most of the weather data for annual daylighting simulations available to designers, such as the US-DOE’s collection of TMY data, can only be used in mathematical sky models such as the Perez all-weather model. It is also essential that real world, complex light-path scenarios commonly found in buildings be addressed by validation in addition to the simple single room, single opening tests which are prevalent in the daylight simulation field. A dataset suite is proposed, similar to the BESTEST suite for energy simulation, which covers basic analytical test cases for lighting simulators, simple office scenarios and a complex shaded classroom in a tropical climate. The dataset is valuable for the testing of daylight simulators which make use of the common CIE general or Perez all-weather skies. These datasets were used in a trial validation of Autodesk’s 3ds Max Design and Radiance, which included significant sensitivity testing of the two empirical datasets included in the suite. This demonstrated the usefulness of each dataset, and any issues with their data. It also highlighted the key inputs of any simulation model where designers must take significant care. Jake Osborne III III Acknowledgments First and foremost I’d like to thank my supervisor, Michael Donn, for his constant guidance and patience throughout this process. Thanks also to all those at Autodesk, the research funders, for their technical assistance and understanding. Jena Shore, Brenton Wyett, Pierre-Felix Breton, Azam Khan, Ramtin Attar, Alex Tessier, Ebenezer Hailemariam, Adam Arbree, John Kennedy, Ken Pimentel Shane Griffith, and Debra Pothier. Everyone at the Université de La Réunion for their assistance in collecting data, Aurélie Lenoir, François Garde, and Shaan Cory. Many thanks to the Lawrence Berkeley National Laboratory: Andy McNeil, Eleanor Lee, Kyle Konis and Dennis Dibartolomeo, for the use of their data. Thanks to Greg Ward and the rest of the Radiance-Online community for their assistance with Radiance. And of course many thanks my friends, family and fellow building science and architecture postgrads for your continued support and comradeship. Jake Osborne V IV Contents I Preface ........................................................................................................................... I II Abstract ....................................................................................................................... III III Acknowledgments ........................................................................................................ V IV Contents ..................................................................................................................... VII V List of Definitions & Abbreviations ............................................................................ IX VI List of Tables, Figures & Equations ........................................................................... XI 1 Introduction .................................................................................................................. 1 1.1 What is “complex” and why simulate it? ........................................................................................ 2 1.2 Previous validation work .............................................................................................................. 4 1.3 Why More Validation?.................................................................................................................. 5 1.4 Aim ............................................................................................................................................. 6 1.5 Scope ......................................................................................................................................... 6 1.6 Report Outline ............................................................................................................................. 7 2 Method .......................................................................................................................... 9 2.1 Hypothesis .................................................................................................................................. 9 2.2 Methodology ............................................................................................................................... 9 2.2.1 Orthogonal validation ............................................................................................................. 9 2.3 Available datasets ......................................................................................................................11 2.3.1 BRE-IDMP Validation Dataset ...............................................................................................11 2.3.2 CIE 171:2006 – Test Cases to Assess the Accuracy of Lighting Computer Programs ..............12 2.3.3 Lawrence Berkeley National Laboratory 71T test-bed facility ..................................................12 2.3.4 Université de La Réunion Laboratoire de Physique du Bâtiment et des Systèmes ...................13 2.3.5 The validation suite ...............................................................................................................15 2.4 Digital modelling and simulation method/criteria ..........................................................................15 3 Quality Assurance .......................................................................................................19 3.1 Geometry ...................................................................................................................................20 3.1.1 Physical measurements – room dimensions ...........................................................................20 3.1.2 Physical measurements – window dimensions .......................................................................20 3.1.3 Model geometric detail ..........................................................................................................21 3.2 Materials ....................................................................................................................................23 3.2.1 Measured reflectance data ....................................................................................................23 3.2.2 Simplification of material data ................................................................................................24 3.2.3 Glazing material properties ....................................................................................................24 3.2.4 Glazing transmittance: maintenance issues............................................................................24 3.3 Sky models & associated measured inputs ..................................................................................25 3.3.1 Discontinuous skies represented by continuous sky models ...................................................26 3.3.2 Measured light and dew-point data ........................................................................................28 3.4 Sensor point placement & tilt tolerances ......................................................................................28 3.5 Data discarding ..........................................................................................................................29 3.6 Summary ...................................................................................................................................30