Double Hung Performance

The U-Factor rates how a window conducts non-solar heat flow. The lower the U-factor, the more energy-efficient the window is. The National Fenestration Rating Council U-factor ratings represent the entire window performance, including frame and spacer material.

Request the U-Factor information from your contractor or authorized Order Windows Online distributor for the product line or window you are considering. All OWO products feature NFRC data to provide fair, credible, and accurate information on product performance. Ask your OWO expert about U-Factor ratings today!

This product rated, certified, and labeled by National Fenestration Rating Council® (NFRC) - a non-profit organization that provides fair, accurate and credible energy performance ratings for windows and doors.

This product meets stringent energy efficiency guidelines set by the U.S. Environmental Protection Agency and the U.S. Department of Energy. These guidelines are based on the heat gain and loss of each product in various regions of the country.