Can Window Film be Used on Low E Windows?

Low E glass has a special coating that reduces ultraviolet and infrared light from passing through its glass. Find out how adding window film can give it even more benefits.


Can window film be used on Low E windows?

You’re probably aware that Low-Emissivity, or Low E glass, is glass with a special coating that reduces the amount of ultraviolet and infrared light that passes through the glass – without compromising the visible light that’s transmitted. So, if a window is labeled Low E glass, does window film give it added benefits?

The Madico U answer is – yes … in most cases.

Whether window film should be used on Low E windows and how much you benefit depends on three factors: the type of Low E surface; the location of the Low E surface on the window; and the amount of heat gain reduction, heat loss reduction, or other window film benefits that your customer is looking for.
Basically, there are two types of Low E surfaces on glass: one is a conductive coating that’s put on the glass as it’s being made. This kind offers some heat loss reduction but doesn’t do much to reduce heat gain into a building.

The second type is a more complex system of multiple layers of metals and conductive coatings deposited on the glass after it has been made. This type of Low E glass gives heat reductions of 30% to 50% in addition to reducing heat loss.

Obviously, there will be more heat gain reduction using film on the first type of Low E glass. If there is any question about the type you may have, ask your glass company or the window manufacturer to send you the specific information about your glass.

Where the Low E surface is located on the window system will also play a role on whether to use window film or not.

If the Low E coating is on the innermost room-side of the window pane, installing window film may cut down or eliminate heat loss reduction on the glass.

However, most Low E window systems are made of double pane windows and the Low E surface is located in the space between the panes. With this type, film can be installed without eliminating the benefit of heat loss reduction of Low E glass.

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