Spectrally Selective Glazings for Residential Retrofits

A large fraction of Californias energy consumption and peak demand results from the need to cool residential buildings with high levels of solar heat gain transmitted through windows. For example, single family residences with central air conditioning built before 1978 consume from approximately 800 kWh per household in the Sacramento Municipal Utility District (SMUD) territory to 2,000 kwh per household within the northern Pacific Gas and Electric (PG&E) and Southern California Edison (SCE) central valley and inland territories. For a new demonstration home being built in the Sacramento area, SMUD reported that 52% of the peak summer cooling load was due to solar heat gain from windows. In cooling-dominated portions of California, where this energy problem is most severe, clear single-pane glass having the highest solar heat gain of any glazing type, is the most prevalent glazing found in existing residences.