Getting Quality Window Replacement: A Comprehensive Guide – Part III: The Plus Factor – Energy Efficiency

According to Environmental Protection Agency’s energy conversation program ENERGY STAR®, an average American household can spend at least $2,200 on energy expenses annually, with about half going to heating and cooling costs. Choosing energy-efficient windows can help you control these costs, taking advantage of advancements that contribute to cutting utility bills and making your home more comfortable. Energy-efficient window replacements are evaluated and rated accordingly, so you shouldn’t have any problem choosing the right one for your needs. How to know you’re looking at the right options? Check labels.

Understanding Energy Efficiency Labels

There are two you can look at to determine if a window replacement is an energy-efficient option: one from ENERGY STAR® and the other from the National Fenestration Rating Council (NFRC). By default, all windows under the ENERGY STAR program will have labels from the two so even without going into specific ratings, just seeing ENERGY STAR and NFRC labels mean you’re on the right track.

Window energy efficiency performance vary depending climate. ENERGY STAR is meant to evaluate if a product was made and equipped with features that meet the energy efficiency requirements for a certain area. For instance, in the northern zone, windows must suit heating needs while the southern zone mostly requires cooling features. More specific energy efficiency ratings are provided in the NFRC label.

Before a window can get an ENERGY STAR® sticker, it must first be independently tested, certified, and verified by the NFRC. While not all will appear in an NFRC label, the following criteria are used to rate windows:

• U-Factor. This measures the rate of heat transfer that a window allows and how well it insulates. The values range between 0.25 and 1.25. The lower the U-factor, the better the window prevents indoor heat from getting out and outdoor heat from getting in.

• Solar Heat Gain Coefficient. This measures the fraction of solar energy transmitted through a window, telling how well can the window block unnecessary heat gain. The values range from 0 to 1, and the lower the number, the less solar heat is allowed.

• Air Leakage. This measures the rate of air passage through the joints of a window. It is measured in cubic feet of air passing through a square foot of window area per minute. A rating not beyond 0.30 is best for ensuring minimal air leakage.

• Visible Transmittance. This measures the amount of light that the window lets in. The values range between 0.20 and 0.80. The higher the value, the more natural light a window lets in.

• Condensation Resistance. This measures how well the window can resist water, moisture, and condensation buildup. The values range from 0 to 100. The higher the value, the better the window can resist condensation.

If you are set to replace your windows, there is no doubt that energy-efficient windows will make good investments. Don’t hesitate to talk to a reputable window contractor today so they can walk you through the ins and outs of energy-efficient windows and quality installation.