SOLAR GAIN AND COOLING LOAD COMPARISON USING ENERGY MODELING SOFTWARE

Single zone models are sometimes used by architects, engineers and energy consultants as a decision making tool for facade and system selection. Most often, the intent of these models is to analyze thermal performance and facade measures. Tools such as eQuest, IES, TRACE, and EnergyPlus are frequently used to perform such analysis. Each of these software tools rely on a certain calculation methodology and embedded are unique algorithms to convert the instantaneous space gain to cooling load. Following this, the cooling load calculation to system calculation transition is not always clear. Understanding these transitions is particularly important in order to use the results appropriately. The intent of this paper is to evaluate the solar gain calculation methodology within each software’s load calculation and its effect on resultant cooling loads on systems. The paper will compare the results of each software’s solar gain and cooling load calculations and describe the solar gain to cooling load transition. The goal of the study is to present watch-its and lessons-learned in comparing facade options for a single zone model using different software. This is achieved by building single-zone models with two different glazing/shading configurations in eQuest, IES, TRACE700 and EnergyPlus.