Low-E glass blocks heat, UV rays in summer and winter
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
"The accepted norm is the low-E coating," says George Fitzenberger, co-owner of highly rated Exterior Enhancements Inc. in Minneapolis.
"I've had customers tell me that on hot days, sometimes they don't even have to turn on their air conditioning. The energy efficiency is very high. The high-end glass blocks a tremendous amount of heat, and they also block UV rays, which puts less wear and tear on your furniture."
The downside, he says, is that during cold winters, such glass also blocks any heat coming into the house from outside. But most of his customers consider that an acceptable tradeoff.
He also adds that not all low-E glass necessarily qualifies for the federal energy efficiency tax credit. To qualify, glass must have both a U-factor and solar heat gain coefficient of 0.30 or less, so check the documentation carefully.
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