Daylighting performance of offices with controlled shades

摘要

Energy conservation in buildings is critical in order to reduce energy consumption and greenhouse gas emissions. This paper presents a dynamic daylighting simulation model to evaluate the combined impact of facade design parameters on the overall daylighting performance of perimeter office spaces. Annual advanced daylighting metrics and lighting energy consumption are computed as a function of the following facade design parameters: window-to-wall ratio, glass transmittance, controlled shading transmittance and orientation, for three different locations in the United States. Initially the analysis is performed without shading, followed by automated operation of roller shades preventing direct sunlight to enter the space for each orientation in order to avoid glare. For all locations, daylight "saturation" is observed for window-to-wall ratios higher than 40%. The results show that for private offices, north and east facing facades allow higher daylight provision due to shading operation during working hours. Energy savings due to reduction in lighting energy using lighting controls demand are analytically presented for all studied cases.