Factors For Finding the Right Window Glazing


Window installation and replacement is eventually an issue most homeowners need to address. Of course, when replacing windows, the idea is that the new ones outperform the old. Selecting features like foam-filled window frames and sashes considerably improve insulation. But what’s the best choice in window glazing?

Performance evaluations for window glazing examine three qualities: how well the glazing insulates, how much light passes through it (visible transmittance, or VT), and how efficient it is at deflecting solar heat (solar heat gain coefficient, or SHGC). Triple-paned windows generally outperform double-paned ones on insulation and SHGC. Tint, on the other hand, affects all three measures. Most windows are gray – or bronze-tinted to allow in less light and heat. By comparison, blue and green window tints permit more light penetration.

The best choices for new window installation also factor in the home’s geographical location, the local climate, as well as the position, function, and directional orientation of the windows themselves. Southern exposure favors indoor plants, for example, but they strain to thrive behind windows with less than 70% VT. Different glazings may be better suited for the functions and locations of all the windows in a given home.