Reflect the heat with low-E windows, expert says

"Our front windows face southwest. We have no shade trees in the front yard, so we are expecting the front rooms to get hot this summer. We plan to replace the glass, but I am getting conflicting advice. Should I get low-E glass and rely on it to block the infrared heat waves, or get clear glass and have an IR-reflective film applied? Which will give me the best results?" — Angie's List member Roger Linville

He should stick with low-E glass, says Jon Koloms, vice president of highly rated Scientific Home Services, which serves Cook, DuPage and Lake counties from its Skokie, Ill., location.

"Low-E glass works to reflect the heat from the sun back outside," Koloms says. "Film is good if you want to cut the brightness of the sunlight itself, but low-E glass is best for heat."

Koloms says low-E glass is measured in two ways: Solar heat gain coefficient (how well the window blocks heat) and U-factor (the window's resistance to heat loss.) In both cases, you should look for a rating of 0.3 or lower in order to qualify for the energy efficiency tax credit.

"The U-factor is particularly important in the Midwest, because it tells you how well the window keeps heat inside and reduces heating costs."

He also recommends looking for glass that blocks ultraviolet rays, which cause furniture, drapes and carpets to fade.

"Most low-E glass blocks about 85 percent of UV rays, but some glass, like the SolarBand product, can block up to 99.97 percent," Koloms says.

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