If you’re in the market for new windows, you should take claims such as “guaranteed energy savings” and “guaranteed reductions to heating and cooling bills” with a dose of skepticism.
Federal Trade Commission in February 2012 announced that it settled with five window companies over deceptive and misleading energy-efficiency claims. As part of the settlement, the companies no longer are allowed to claim that their windows will achieve a specified amount of energy savings or a reduction to heating or cooling bills unless the company has scientific evidence to back up such claims. The companies also are prohibited from claiming that a specific number of consumers who replace their windows with those of the company will achieve energy savings.
Consumers Digest reported about how to measure a window’s energy efficiency in its September/October 2010 issue (“Performance Reviews”), and consumers are encouraged to consider a window’s U-factor and solar heat-gain coefficient based on the climate in which they live.