How to tell if your windows have Low-E glass

Quick Guide:
- Place lighter, or laser, close against the glass and look at the 4 reflections of the light.

- If 1 of the 4 reflections are a slightly different color, this indicates the presence of Low E glass. (see flame 3 on image above)

- If all the reflections are the same color, you do not have Low E glass.

First, let us understand what Low-E means. Low-E means “low emissivity” is an extremely thin layer or layers of a metallic particles coating applied to the glass usually on the interior side of the outer pane for double-pane windows. The coating reflects radiant infrared energy or heat from the outside while still letting in visible light. This also reflect the heat back inside your house if you have your heater running, thus keeping your home warm.

Now, to test if your window has Low-E coating, simply use either a match/lighter or a pen light. We recommend using a lighter as that is the easiest way to tell the difference between the flame’s color. Place it close to the window where you can see 4 reflections of the flame (two for each panel). If one of the four reflections has a different color, then you have Low-E coating on your window.

Greenfilm window tints are not suitable if you have the Low-E coating on your windows.