Solar shading performance of window with constant and dynamic shading function in different climate zones

Window is a basic building element that can significantly influence the indoor thermal and lighting environment, in evaluating the shading performance of a window system with shading device, the solar heat gain coefficient (SHGC) is of key factor. This paper analyzed the optimal constant solar heat gain coefficient (SHGC) in several typical climate zones in USA and China, the SHGC values were compared according to their latitudes. Based on a grid shading configuration for window, the optimization of grid pitch for energy saving was conducted. The optimal SHGC decreases gradually with the decrease of latitude, the effect of shading device becomes more obvious. The window with optimal SHGC could reduce total building load up to 37.8% in selected USA cities and 24.8% in selected China cities. For the same city and grid pitch, more than 6 times difference emerges from summer to winter. The minimum geometrical shading coefficient (GSC) of grid shading increases with the decrease of latitude.