Calculating the Effect of External Shading on the Solar Heat Gain Coefficient of Windows

TitleCalculating the Effect of External Shading on the Solar Heat Gain Coefficient of Windows
Publication TypeConference Paper
Year of Publication2017
AuthorsChristian Kohler, Yash Shukla, Rajan Rawal
Conference NameBuilding Simulation 2017
Date Published08/2017
Conference LocationSan Francisco, CA
Abstract

Current prescriptive building codes have limited ways to account for the effect of solar shading, such as overhangs and awnings, on window solar heat gains. We propose two new indicators, the adjusted Solar Heat Gain Coefficient (aSHGC) which accounts for external shading while calculating the SHGC of a window, and a weighted SHGC (SHGCw) which provides a seasonal SHGC weighted by solar intensity. We demonstrate a method to calculate these indices using existing tools combined with additional calculations. The method is demonstrated by calculating the effect of an awning on a clear double glazing in New Delhi. 

LBNL Report Number

LBNL-2001057