Paper Conference

Proceedings of SimBuild Conference 2004: 1st conference of IBPSA-USA


Development of Trade-Off Equations for Energystar Windows

Joe Huang, Robin Mitchell, Steve Selkowitz, Dariush Arasteh, Bob Clear
Lawrence Berkeley National Laboratory, Berkeley CA

Abstract: The authors explore the feasibility of adding a performance option to DOE's EnergyStar © Windows program whereby windows of differing U-factors and SHGCs can qualify so long as they have equivalent annual energy performance. An iterative simulation procedure is used to calculate trade-off equations giving the change in SHGC needed to compensate for a change in U-factor. Of the four EnergyStar © Window climate zones, trade-off equations are possible only in the Northern and Southern zones. In the North/Central and South/Central zones, equations are not possible either because of large intrazone climate variations or the current SHGC requirements are already near optimum.