Windows are responsible for 25%-30% of a home’s energy loss. You can reduce this loss with energy-efficient windows rated for your climate.
Look for whole-unit U-factors, SHGC, Visible Light Transmittance (VT), air leakage and condensation resistance ratings on the NFRC label. These ratings are based on independent research. The higher the rating, the more energy efficient the window.
ENERGY STAR®
In addition to reducing energy bills, ENERGY STAR® certified windows provide the best protection against damaging UV and infrared rays. This helps keep carpets, furniture, and floors from fading.
During your window selection process, look for whole-unit U-factor and Solar Heat Gain Coefficient ratings. These measurements from the National Fenestration Rating Council indicate a window’s performance and help you make comparisons.
Energy-efficient windows are more expensive than traditional single-pane windows, but they save homeowners money each year with their exceptional thermal performance. Additionally, they reduce drafts and air leakage, and qualify for tax credits. Choose from a wide variety of window styles and options including:
LOW U-Factor
The U factor, or U value, reflects the rate of non-solar heat loss through an entire window assembly. This number combines with solar heat gain, visible transmittance, air leakage, and condensation resistance to help you choose energy efficient windows for your home and climate zone.
The temperature difference between a building’s interior and exterior generates this non-solar flow, which causes windows to lose heat to the outside during cold weather and allow the sun’s warmth into the house in summer. A lower U-factor rating can improve your energy efficiency and comfort level. For the best results, consider triple-pane windows that separate the panes with energy efficient argon or krypton gas to significantly reduce thermal transfer.