What is a Low-E window and why are window film applications restricted on them?
The “E” refers to the emissivity of the window unit – It’s ability to absorb heat and reflect it back into the room. The lower the emissivity, the less room heat is absorbed – thus more heat is reflected back into the room. This effectively creates a “heat trap”. The primary job of a Low-E window is to reduce heat loss and not heat gain. Depending upon the type and location of any Low-E coating, restrictions or even prohibitions against installation of certain window films may exist. The wrong film applied to a Low-E glazing system could lead to premature failure of the I.G. unit or possibly even glass breakage. We have testing equipment to determine the presence of Low-E coatings and the various film manufacturers have application guidelines to which we strictly adhere, to prevent problems arising from a window film installation.
