Energy Efficient Window Tips
Windows can be one of your home’s most attractive features. Windows provide views, daylighting, ventilation, and heat from the sun in the winter.
Unfortunately, heat moving in and out of your home through windows can increase your heating and air conditioning bills. Energy efficient windows and measures to reduce heat gain and loss can help save energy and reduce energy bills.
Buying Energy Efficient Windows
Look for the ENERGY STAR label when buying new windows. Also review ratings from the National Fenestration Rating Council (NFRC). NFRC ratings are included on all ENERGY STAR certified windows and provide a reliable way to determine a window’s energy properties and compare products.
Replacing single-pane windows with double-pane windows that have high-performance glass may be cost effective, but you could also consider installing exterior storm windows.
You can obtain energy efficiency ratings for storm windows and other window attachments from the Attachments Energy Rating Council (AERC, aercnet.org). In colder climates, 21 consider selecting gas- filled windows with low-e coatings to reduce heat loss. In warmer climates, select windows with coatings to reduce heat gain.
Choose a low U-factor for better thermal resistance in colder climates; the U-factor is the rate at which a window conducts non-solar heat flow.
Look for a low solar heat gain coefficient (SHGC). SHGC is a measure of solar radiation admitted through a window. Low SHGCs reduce heat gain in warm climates.
Select windows with both low U- factors and low SHGCs to maximize energy savings in temperate climates with both cold and hot seasons.
Look for whole-unit U-factors and SHGCs, rather than center-of-glass U-factors and SHGCs. Whole-unit numbers more accurately reflect the energy performance of the entire product.
Have your windows installed by trained professionals according to manufacturer’s instructions; other- wise, your warranty may be void.
