Double-glazed, Low-solar-gain Low-E Glass, Argon/Krypton Gas

This figure illustrates the characteristics of a typical double-glazed window with a low-solar-gain low-E glass with argon gas fill. As with moderate-solar-gain low-E glass, these windows are often referred to as spectrally selective low-E glass due to their ability to reduce solar heat gain while retaining high visible transmittance. Compared to most tinted and reflective glazings, this low-E glass provides a higher level of visible light transmission for a given amount of solar heat reduction. Variants on low-solar-gain low-E coatings have also been developed which may appear slightly tinted. This type of low-E product reduces heat loss in winter and substantially reduces solar heat gain both in winter and in summer. Thus, low-solar-gain low-E glazings are ideal for buildings located in cooling-dominated climates.

Low-solar-gain low-E glass is typically made with sputtered low-E coatings consisting of either two or three layers of silver (also called double-silver or triple-silver low-E).

Note: These values are for the center of glass only. They should only be used to compare the effect of different glazing types, not to compare total window products. Frame choice can drastically affect performance.