Double-Glazed with Bronze or Gray Tinted Glass

This figure illustrates the performance of a typical double-glazed unit with bronze or gray tinted glass. The outer layer of glass is bronze or gray and the inner layer is clear. These two layers are separated by an air gap. Double glazing, compared to single glazing, cuts heat loss in half due to the insulating air space between the glass layers. Bronze and gray tinted glass products are similar in energy performance. The primary purpose of the bronze or gray tint is to reduce solar heat gain. But, it also reduces visible light transmission compared to Double-Glazed with Clear Glass or even other standard tinted glass products such as green and blue tints which offer significantly higher visible light transmission. Tinted glass is useful in controlling glare but solar heat gain and visible light transmission may be reduced relative to the performance of alternate glazing options such as High-Performance Tinted Glass or Low-E Glass with Moderate or Low-E Glass with Low Solar Gain. The tint has no effect on the U-factor but reduces solar gain which may be a benefit in the summer and a liability in the winter depending on local climate conditions.

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. These values represent double glazing with a 1/2" air gap. Aluminum units use 3/8" air gap, where the U-factor is 0.52 and the SHGC and VT remain the same.