What Is Low-E Glass and Why Does Every Spec Call for It?

Low-E stands for low emissivity. The coating is a metallic layer thinner than a wavelength of light, applied to a glass surface inside the sealed unit, that reflects radiant heat while letting visible light pass.

Winter and summer, one coating

In an Ontario winter, a Low-E coating reflects interior heat back into the room instead of letting it radiate out through the glass. In summer, it reflects solar heat away before it loads the cooling system. The same physics works both directions.

Why it is on every modern spec

Energy codes and efficiency programs have made Low-E the de facto standard because it improves a window's overall performance for a small share of the unit cost. Paired with argon gas fill and a warm-edge spacer, it turns an ordinary IGU into a high-performance one.

Specifying Low-E with NAGC

We manufacture IGUs with Low-E options in double, triple, and quad configurations at our Guelph facility, with 5 to 7 day average lead times. Tell us your performance target and we will recommend the configuration.