LOW-E COATINGS

Low emittance (Low-E) coatings are microscopically thin, virtually invisible, metal or metallic oxide layers deposited on a window glazing surface primarily to reduce the U-factor bt suppressing radiative heat flow. The principal mechanism of heat transfer in multilayer glazing is thermal radiation from a warm pane of glass to a cooler pane. Coating a glass surface with a low-emittance material and facing that coating into the gap between the glass layers blocks a significant amount of this radiant heat transfer, thus lowering the total heat flow through the window. Low-E coatings are transparent to visible light.

There are many grades and names for Low-E coatings and can be very confusing. Low-e was the original generation of low emmitance coatings. It was great for its time, but had flaws. The coating was applied to the outside of the pane and thus exposed to Mother Nature and to us. When cleaned it was scratched and over time degraded. Low-E2 was the second generation and as the name impies it was two coats instead of one. Eventually the coatings were put on the inside between the two panes of glass which eliminated the exposure and scratching problem. There are now many names and levels of Low-E coatings available. To name just a few of them in addition to above two listed, there is 272, 366, Solarban 60, Solarban70.

Watch the Low-E 366 Test Video

Glass Options