Block the Sun and Lower Your Energy Costs With Window Coverings

Awnings, curtains, blinds, and shades can keep you cool—and keep your utility bills in check

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Sunlight coming through open window blinds. Photo: iStock

Air conditioning feels blissful during the height of the summer, but running it nonstop will have you boiling when you get your utility bills.

The clever use of blinds, curtains, and other window treatments can help keep your house cool and your bills in check. The Department of Energy says the smart management of window coverings can reduce heat gain by up to 77 percent. (And, as a bonus, these same practices can reduce heat loss in the winter.) Here are some energy-saving suggestions from the DOE that will pay off immediately.


Window awnings can reduce solar heat gain by up to 65 percent on south-facing windows and 77 percent on west-facing windows, according to the DOE. For best results, choose awnings in light colors that reflect more sunlight. In the winter, you can roll up retractable awnings to let the sun warm your house.

Curtains and Drapes

On summer days, keep your curtains closed. "Particularly on the side of the house or apartment where the sun is coming in," says Allan Drury, a spokesman for Con Edison, the New York energy company.

More on Keeping Cool

The ability of curtains and drapes to reduce heat gain depends on the fabric type (closed or open weave) and color. Studies have found that medium-colored draperies with white plastic backings can reduce heat gain by 33 percent, the DOE says.

Hang the curtains as close to windows as possible. For maximum effect, install a cornice at the top of the draperies, seal the draperies at the sides, and overlap them in the middle using Velcro or tape.


When properly installed, window shades are one of the simplest and most effective ways to save energy, but they need to be drawn all day to work. Mount them as close to the glass as possible within the window frame, creating a sealed space. Reversible shades that are white on one side and dark on the other can be switched with the seasons, with the white side reflecting the sun in the summer and the dark side absorbing its heat in the winter.

Quilted roller shades and Roman shades with several layers of fiber batting serve as both insulation and an air barrier and are more effective than other soft window treatments.


Because of the horizontal slats, it's difficult to control heat loss through interior window blinds, although they do offer some flexibility. Unlike shades, you can adjust the slats to control light and ventilation. When completely closed, highly reflective blinds can reduce heat gain by around 45 percent, says the DOE. They can also be adjusted to block and reflect direct sunlight onto a light-colored ceiling, which diffuses the light without much heat or glare.

Reflective Film

Window film is best for homes in regions with long cooling seasons. Silver mirrorlike film is typically more effective than colored, more transparent film, and east- and west-facing windows benefit most because of their greater potential for heat gain. Keep in mind that reflective film is tricky to clean and, obviously, may affect your view.

If You Really Need AC

You should also take the heat of the sun into consideration when installing a window air conditioner. If you place the unit in a window that gets direct sunlight during the hottest part of the day, it will have to work harder to keep you cool. And that'll cost you.

Here are the best small, medium, and large window ACs from CR's air conditioner tests, plus the top portable model. For even more options, see our complete air conditioner ratings and check our air conditioner buying guide as you shop.

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