Window film cannot be used on Low-E glass.

False! But it depends on what surface of the window the Low-E coating is. If the Low-E coating is on the #2 surface of a single pane unit or #4 surface of a double-pane unit, window film will negate the coating. Otherwise, window film can be installed on Low-E glass.

Low-E glass is most relevant during the winter heating season. Heat likes to travel from places of hot to cold. Imagine a room in your home or office in January. The HVAC system produces heat to warm the interior space. That heat wants to go where it’s cold, which is outside. And it travels outside by the path of least resistance, which is typically right through the window’s pane of glass. As the heat escapes, the temperature in the room declines. So your HVAC system turns back on to heat the space once again. That is why you hear your HVAC system turn on and off intermittently when you set your thermostat to an automatic setting.

Low-E windows help reduce that heat loss by reflecting part of the heat back inside, thereby reducing what is lost outside. Low-E windows are efficient and expensive, and not everyone has them. If your building or home does not have Low-E windows, a 3M insulating window film like Thinsulate Climate Control 75 can turn your non-Low-E windows into Low-E windows and make your home warmer in the winter.

If you do have Low-E windows and would like window film applied for the benefits during the summer, it is important to know on what surface the Low-E coating is. Installing film directly on top of that special Low-E coating will negate the coating, and you will notice an increase in your wintertime heating bills.

Your 3M Authorized Window Film Dealer will know whether or not window film will cancel the Low-E coating on your windows.