Stephen Lee, professor in Carnegie Mellon’s School of Architecture, explains how windows can affect our home energy use.

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Energy Efficient Windows from the U.S. Department of Energy

Repair and Upgrade Windows and Doors from the National Park Service

Frequently Asked Questions from Home Energy Saver

Transcript

HOST: Have you wondered whether you should get new windows to improve the energy efficiency of your home? On this week’s Energy Bite, Stephen Lee, a professor at Carnegie Mellon University, has some answers.

LEE: There are two sources of energy consumption related to windows. The first is the loss or gain of heat through the window’s glass. If you have old wood-framed single-pane windows, you should consider replacing them. The second source is air leakage around the frames. Older Pittsburgh homes with poorly-sealed windows can leak 10 times the air you paid to heat or cool every hour of ever day compared with properly installed new windows.

HOST: How do you know if replacing the windows make economic sense?

LEE: The cost of the new windows in a pre-WWII war home in Pittsburgh will be paid back in approximately 10 years. But don’t replace your windows until you have first insulated your roof and walls, which has a payback time of only 3 years.

To find out whether or not you need new windows due to air leakage, you will need an energy auditor to do a “blower door” test of your home.

HOST: Would you invest in new windows for your home? Take our poll, see the results, and ask your energy questions at Energy Bite dot org.

ANNOUNCER: Energy Bite is a co-production between 90.5 WESA and Carnegie Mellon’s’ Scott Institute for Energy Innovation.