Impacts of Shading and Glazing Combinations on Residential Energy Use in a Hot Dry Climate

Abstract

A residential building in Tucson, Arizona, was studied to evaluate opportunities for reducing cooling energy use in a hot dry climate. The reduction of solar heat gain was strongly influenced by spectrally selective windows, architectural shading, and site shading from adjacent buildings. The study emphasized accurately modeling these features to account for effects on the energy load. Building performance was modeled using a detailed hourly energy simulation tool and was measured while unoccupied for a period of 12 days. Model inputs included direct measurements of the net air exchange rate, surface reflectance, and window transmittance. Model results showed good agreement with the direct measurements of cooling loads and air-conditioning energy use. A parametric study of annual energy use is presented showing the impacts of glazing type, architectural shading, site shading, and building orientation. It is important to understand these interactions to optimize energy savings in community-scale housing developments.