Summer-heat-gain control in passive-solar-heated buildings: fixed horizontal overhangs

An aspect of passive cooling relates to cooling load reduction by the use of solar controls. When there is a substantial winter heating requirement, and when the winter heating needs are met in part by a passive solar heating system, then the potential aggravation of summer cooling loads by the heating system is an important design issue. A traditional solution is the use of a fixed, horizontal shading overhang. An approach to quantitative design rules for the sizing of a shading overhang to minimize total annual space conditioning energy needs is outlined.