You finally drift off to sleep after hours of commute home in a storm. Just as you count your last sheep, “WHOOOOO” howls through the gaps in old windows and you’re wide awake again. The chill in the air has you wrapped up like a mummy in your blankets. Visions of the water damage you’ll wake up to dance in your head. The decision to replace your windows may come suddenly, but how do you chose the right replacement windows for your home?
1. NFRC Label
The National Fenestration Rating Council (NFRC) is a nonprofit organization who provides consistent and accurate information regarding the energy performance of windows, doors, and skylights. NFRC also publishes consensus standards (for consistent ratings), and administers a third-party certification and labeling program to provide verified product information to the window buyer.
The NFRC Label is generally black and white with the name of the window’s manufacturer at the top. Important information printed on the sticker includes:
U-Factor – The lower the U-factor, the less heat escapes in the winter, which is particularly important in cold northern climates. In the summer it means less heat that gets in. Pay close attention to determine if the manufacturer’s U-factor number applies to the entire unit, not just the glazing.
Solar Heat Gain Coefficient – SHGC refers to the solar radiation a window allows inside your home. In warm climates, find the lowest possible SHGC rating to minimize your use of air conditioning. In cooler climates, a slightly higher number allows the sun to warm your home in winter. Be sure, however, to balance SHGC with the appropriate U-factor for your area.
Visible Transmittance – The amount of visible light allowed to pass through the glazing is rated as visible transmittance. The rating applies to windows or doors with windows. With older window glass, a bright sun-lit room also meant a lot of heat too. New technologies allow a lot of light in, while the room stays cool.
Air Leakage – This measure is expressed in cubic feet per minute per square foot of window/door area. The number indicates the amount of air the window’s frame allows through. Compare similar products with this measurement to eliminate drafts and howling.
Find the NFRC label on windows for a fair way to compare products for sale.
2. ENERGY STAR Label
The ENERGYSTAR designation was developed by the U.S. Department of Energy and the U.S. Environmental Protection Agency for products which meet certain energy performance criteria. The sticker is blue with the graphic of a star.
Because efficiency of windows, door, and skylights will vary by climate, recommendations are different for each of four climate zones: a mostly cooling zone (Southern), two heating and cooling zones (South/Central and North/Central), and a mostly heating zone (Northern).
Visit www.energystar.gov for more information about ENERGY STAR windows.
Don’t spend one more drafty night in your home full of old windows. Use these two labels to quickly and easily find the right replacement windows for your home. You and your house deserve it!