How much glass will it take to utilize passive solar?
It depends on how much the client wants to do. A house with south-facing glass equal to 12 percent (glazing percentage) of its heated space is called sun tempered. It can get about 10-30 percent of its annual space heat from the sun without adding extra mass to store daytime heat for nighttime use. By increasing the south glass to 20 percent of the home’s heated floor area, a home can achieve up to 50 percent solar savings with the addition of some heat storing materials (thermal mass). To achieve a 60 percent reduction in a home’s conventional heating requirements normally requires multiple systems including an attached greenhouse and around 30 percent glazing percentage with added mass storage.
