But new windows do more than just look good. They're also a source of heat, and need to be tinted or shaded to reduce heat, but those options also reduce natural light. And not only do windows increase a room's temperature fluctuation, but incoming light can also cause fading of carpets, fabric, wallpaper, paint and wood.
By using energy efficient replacement windows, you can reduce light and heat transfer, as well as heating and cooling costs.
According to the U.S. Environmental Protection Agency's Energy Star Program U.S. Environmental Protection Agency's Energy Star program, which began in 1992 as a voluntary labeling program designed to identify and promote energy-efficient products, the average household spends more than 40 percent of its annual energy budget on heating and cooling costs. You can save 15 percent of that with Energy Star-qualified windows.
The Efficient Windows Collaborative, a group that manufactures and promotes energy-efficient windows and receives support from the U.S. Department of Energy's Windows and Glazings Program, says the most harmful sunlight rays are ultraviolet (UV), which are the most energetic and most likely to break chemical bonds, leading to fading and degradation of materials with which the light comes in contact.
The EPA says that windows with Energy Star labels are energy efficient all year long and are twice as efficient as the average window produced 10 years ago. They're available in aluminum, fiberglass, vinyl and wood, and include design styles such as single-hung, double-hung, casement, horizontal slider, fixed and picture, as well as patio slider.
All Energy Star windows are labeled by the National Fenestration Rating Council, a non-profit, public/private organization created by the window, door and skylight industry and comprised of manufacturers, suppliers, builders, architects and designers, specifiers, code officials, utilities and government agencies. The NFRC provides unbiased energy performance ratings on window, door and skylight products.
The NFRC suggests looking for the following when choosing replacement windows:
- U-factor, or how well a window keeps heat inside a building. The lower the U-Factor, the greater a window resists heat transfer. A good U-Factor to look for is 0.35 or lower.
- Solar heat gain co-efficient (SHGC), or a window's ability to block warming caused by sunlight. The lower an SHGC number, the less UV rays that cause heat gain are coming through a window. Look for an SHGC number of 0.40 or lower.
- Visible transmittance (VT), or how much light gets through a product. A VT number is a direct percentage of available light coming through a window - the higher, the more light coming through. A good percentage is about 55 percent.
- Air leakage, or heat loss and gain by infiltration through cracks in the window assembly.
- Low-E coatings, a microscopically thin, virtually invisible metal or metallic oxide layer deposited on the glass during manufacturing. Low-E coatings reduce heat transfer through the glass, and can reduce UV rays that cause heat gain by up to 75 percent and reduce fading of interior furnishings.
And of course windows offer style as well as function.
Design options from manufacturers include Pella's integrated crank that features a fold-away handle for casement windows, KML by Andersen architectural windows in radius-top casements and double-hungs, and Andersen Art Glass in 11 original patterns including Frank Lloyd Wright series designs.
Window manufacturer Owens Corning suggests choosing a window style that complements your home's current window system. And keep in mind that the windows you select express your personality and can give your home a great new look.
New windows are a feature of your home you're sure to enjoy. And with products like Energy Star windows, you'll save money now by reducing heating and cooling costs, and in the future by using the windows as a selling point when you're home's on the market.