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California Energy Study
C A L I F O R N I A E N E R G Y C O M M I S S I O N
Shading the outside of your home can reduce the temperature
We've got your windows covered!
In good weather and bad, windows let you enjoy the beauty of the great outdoors without leaving the comfort of your easy chair. Through the windows of your home, you can watch your children at play, observe a hummingbird fluttering next to a feeder, and even admire the power of lightning and the colors of a rainbow on a stormy day.
There's much more to windows, though, than what meets the eye. Today's windows may have high-tech coatings or contain inert (harmless) gases between multiple panes of glass, both of which increase the insulation value of your windows. In the wintertime, they let in sunshine to brighten and warm your home. When summer arrives, they keep a significant amount of heat from coming inside. In fact, all year long your new, energy efficient windows keep you more comfortable and help to keep your heating and cooling costs down. It's important to keep in mind that even though today's windows are more energy efficient, they're still one of the largest sources of heat loss and heat gain in your house. You can, however, add to the efficiency of your windows and keep your home cool, simply by making the right shading and window-covering choices.
Block the sun before it enters your home!
Shading the outside of your home should be your first line of defense against summertime heat. In fact, shading your home with well-placed trees, shrubs and vine-covered trellises, or wide overhangs, such as patio covers, can reduce the temperature indoors by as much as 20° Fahrenheit on a hot day! Here are a few outdoor shading strategies to consider.
Solar screens resemble standard window screens; however, they can block up to 85% of the sun's rays from entering your home. Not only that, but they cut glare and allow air to flow into your home. But the benefits of solar screens don't stop there. They also help reduce fading of your furniture, drapes and carpeting commonly caused by the sun's rays; they increase your privacy; and they can be made to fit any window opening, including arches and circles.
Awnings are back in fashion, especially retractable awnings. They block direct sunlight and can reduce heat gain in your home up to 77%. They cut glare and help eliminate faded upholstery, drapes and carpet. They can increase the value of your home, reduce your air conditioning and heating costs, and they operate with just the push of a button, making it easy for you to retract them to let the sun inside on cold winter days.
Patio covers are a terrific addition to your home and yard. They provide shade to keep you cooler when you sit outside in the summertime, and at the same time they prevent unwanted sunlight and heat from entering your house. Like retractable awnings, they help eliminate faded upholstery, carpets and drapes, and have the added benefit of increasing the value of your home. It's good to keep in mind that patio covers are permanent — they may block the sun during every season of the year, including winter when the sun's warmth helps to heat your home. If you build a patio cover, check out a variety of plans and consider constructing one that will allow you to take advantage of the wintertime sun.
To keep your home as cool as possible during the summer, close your blinds to keep the sun's heat outside. During the winter, open the blinds and let the sun shine in; on cloudy days and at night, close blinds to keep the warmth inside.
For ways to shade your windows with landscaping, see the fact sheet Landscape now ... and save energy the natural way.
Cover the inside of your windows for an additional line of defense!
Drapes, curtains and blinds are not as effective as exterior shading, but they do provide a small measure of heat resistance when the sun beats directly on your windows. However, when you combine interior with exterior shading, you'll have an extra layer of protection and even more comfort.
Drapes and curtains made from tightly woven, light colored, opaque fabrics reflect much of the sun's rays. Keep in mind when you hang drapes or curtains that the closer they fit against the wall around the window, the better they will prevent heat gain or loss. Another strategy is to hang two layers of drapes, which will offer you better insulation in either hot weather or cold.
Venetian or mini blinds are not as effective as drapes, but they can be adjusted to let in some light and air while reflecting the sun's heat. Like drapes and curtains, light colored blinds are the most effective. Following some of these energy saving suggestions can help to keep your home comfortable in all seasons, as well as giving you lower utility bills year round.
C A L I F O R N I A E N E R G Y C O M M I S S I O N
For more information contact the Energy Commission toll free at 1-800-772-3300
Energy Efficiency Division
Mary D. Nichols,
William J. Keese,
One in a series of Home Energy Guide fact sheets available from the Energy Commission.