Paper Conference

Proceedings of SimBuild Conference 2010: 4th conference of IBPSA-USA


Integrating advanced daylight analysis into building energy analysis

John An, Sam Mason

Abstract: With electric light accounting for about a quarter of the total energy used in U.S. office buildings (CBECS 2003), there is the potential for substantial energy savings through effective daylight design. However, the generic solar radiation and daylight control calculations in commonly used energy analysis software may be too crude to accurately account for the performance benefits of daylight design in buildings. Additionally, energy analysis tools do not address visual comfort and glare concerns which are critical to the success of a daylight design. Using currently available analysis tools, there is the potential to merge daylight and energy analysis to assess the effectiveness of daylight design strategies while accurately gauging the potential lighting energy savings. This integrated approach described in this paper entails a three step process using the analysis programs DAYSIM (Reinhart 2001,, DOE-2.2 ( and evalglare (Wienold 2004) to estimate energy performance and glare potential in buildings. This paper presents initial application of and results from an office building project that utilized an integrated daylight and energy analyses process. Results from the integrated process are compared against the conventional daylighting control calculation method in DOE-2.2, and the results show a meaningful difference in estimated energy savings between the two calculation methods. This paper also presents the results of a glare probability analysis of one office space.
Pages: 310 - 320