Fiberglass and plastic glazings are lighter but less scratch-resistant than glass. Various manufacturers offer windows with single, double, triple, or quadruple glazing. Some window manufacturers use advanced glazing technologies to provide maximum window thermal and optical performance. Low-E coatings reduce heat flow by making the window less transparent to parts of the solar spectrum. A low-E coating can reject unwanted infrared heat from the sun in the summer and keep infrared heat from radiating out of a home in the winter.
Infrared radiation represents just under half of the sun's energy that reaches the earth's surface.
Last updated December 31, 1995.