Low-Emissivity window coatings or Low-E are generally metallic layers on glass surfaces that help control heat intrusion or retention on a structure. But does your window have this feature on any of the glass surfaces? Sometimes there are multiple and sometimes there are none to be found.
Entry level electronic low-e detectors can be purchased for $250 while others are listed north of $3,000. The white LED light on my cell phone is free.
The reflection of a white LED light will reflect either the same color, indicating no coatings, or a hue of magenta, turquoise, or similar indicating the presence of a metallic coating. Take a look at the following image.
Coating 1, 3, and 4 show white as is the color of the light on the cellphone. Coating 2 indicates a coating by reflecting a magenta hue. When applying a light to triple pane windows, it is helpful to increase the angle of your viewing by stepping to the side of the location where your phone is held close to the glass.
The following image shows no coatings.
Very often, low-e coatings are applied to surface 2 and 3 in a double glazed unit. Low-e coatings will often be found on surfaces 2, 3, 4, and 5 in a triple glazed unit. Window films such as tint will be found exclusively on the exterior or interior surfaces such as 1 and 4 in a double glazed unit and 1 and 6 in a triple glazed unit.
Quick and Dirty Low-E Coating Detection
