Comparison of Simulation Tools Mostly Used in Daylighting Performance Studies

Abstract

In recent years, sustainable architecture shows great interest into the daylighting design of buildings, regarding energy saving strategies and user comfort. Increasing usable daylight and creating efficient daylighting strategies help to decrease the total energy consumption and enhance user comfort in the buildings. There are many factors and considerations that need to be taken into account in the process of daylighting design; such as, solar heat gain, glare, artificial lighting control­ dimmers and sensors- and predictable or unpredictable variations in sky conditions. Therefore, commencing the daylighting design in the first steps of the designing process is needed. Computer-based daylighting simulation tools help the designers to make time and cost effective pre-tests before the construction stages and understand how their buildings act under different sky conditions throughout the year. This paper presents the basic principles and the discussion of four daylighting simulation programs that have been more commonly used in daylighting design in the recent years. These programs are Desktop Radiance, DesignBuilder, Autodesk Ecotect Analysis and Velux Daylight Visualizer. In this study, the basic working principles of these programs are discussed and a comparison is made regarding the differences in potential quality of the tools in terms of physical correctness of the results, adaptability for new technologies and usability for design decision support. Other criteria that are taken into account in the comparison are compatibility with third party programs, working as a plug-in or as standalone in nature, user interface, ease of use, characteristics of output data, existence and source of climatic data, daylighting analysis and calculation methods, 3D modeling capability. The paper ends with the discussion of the overview literature results.