Triple-coated windows keep the heat out
"My front windows face southwest. I have no shade trees in the front yard, so I'm expecting my front rooms to get hot this summer. I plan to replace the windows but am getting conflicting advice. Should I get low-e glass, or get clear glass and have an infrared-reflective film applied?" — Angie's List member Roger Linville
"With LoE3, the triple stack coating goes on the exterior plate of the inside surface of the glass, so it's protected from the elements, which prevents it from tarnishing," Gilkey says.
While sunlight easily penetrates clear glass windows, the protective coating of slightly tinted LoE3 glass reflects heat well, thereby avoiding a sort of "greenhouse effect" of heat buildup, Gilkey says.
Tinted film, on the other hand, works best to reflect heat from single-paned glass windows, Gilkey says, since the film is placed on the interior of the window. However, building codes enforce the use of more than one window pane for residential homes, so that sort of glass is usually only found in restaurants.
Low-emissivity glass, on average, he says, can cost 20 percent less than buying and installing tinted film to clear glass windows.
"In addition, applying the film to a window may void the glass manufacturing company's warranty," Gilkey says, "because sometimes the film can cause seal failure in the glass."
Do you have a service-related question? E-mail us at firstname.lastname@example.org.