According to the EPA, Energy Star-qualified windows can save the typical household $125-$450 per year in energy costs when replacing single-pane windows and $25-$110 per year when replacing double-pane clear-glass windows.
What makes a window energy-efficient?
-- Improved frame materials such as wood composites, vinyl, and fiberglass reduce heat transfer and improve insulation.
-- Low-E glass with special coatings reflects infrared light, keeping out summer heat.
-- Gases between the panes, such as argon or krypton, insulate better than regular air.
-- Multiple panes of glass with air or gas in between insulate better than a single pane.
-- Warm-edge spacers keep a window's panes the correct distance apart to reduce heat flow and prevent condensation.
To save energy and keep your kitchen cool at dinnertime, use your grill and microwave instead of the cooktop and oven as much as possible. Plan your schedule so you can run the dryer, dishwasher, and oven in the early morning or evening rather than in the heat of the day. Air-conditioning lowers humidity as it cools the air, so you shouldn't need to run a separate dehumidifier if you have air-conditioning.
Let your heating and cooling system do the thinking for you. When set and used properly, a programmable thermostat can save about $100 in energy costs each year. You should also protect your investment. Schedule annual preseason maintenance checkups with a licensed contractor to ensure your system is operating efficiently. Check the air filter monthly and replace it as needed. Finally, use a caulk gun to seal leaks around windows, doors, and ducts that cause drafts and make your heating and cooling system work overtime.
The recommended temperature setting for comfort and energy savings in an air-conditioned room is 78 degrees Fahrenheit. Resist the urge to drop the temperature for a quick cool, which taxes your cooling unit.
Close your house tightly during the heat of the day. Don't just close windows; lock them to create an airtight seal that eliminates cool-air leaks. If outdoor temperatures are cool at night, cross-ventilate rooms by opening windows. Close them again in the morning to seal in the cool air. Also, close curtains or lower shades during the day.
Reduce the load on your air-conditioner by shading east-, south-, and west-facing windows. Outside, extend roof eaves or add a trellis or awning to shade windows. Add tinted window film to lessen the effects of radiant heat and UV light while maintaining views.
If an attic inspection reveals insulation scattered halfheartedly among the floor trusses, head to your local home improvement center to get more. If you use your attic for storage, don't remove all those boxes; simply insulate between the joints. In terms of reduced energy costs, the payback time for a few hundred dollar's worth of insulation can typically be measured in months, not years.
It's basic, but it's true: If you keep the air in your house moving with a ceiling, box, or window fans, you'll feel cooler. Place window fans in your north-facing windows to draw in the cooler air. Place others in your south-facing windows to push out the hot interior air. Box fans keep the air moving horizontally; ceiling fans should be set so they blow air down during the summer months.
Planting trees on the south and west sides of your house will pay off when they're full-grown. A mature oak or maple can block the sun's most intense rays from heating your home. And during the winter, leafless branches let sunshine through to brighten the interior -- and your spirits.
Your cooling apparatus will work less -- and use less energy -- if you cut back on interior elements generating heat. Ninety-five percent of the energy an incandescent light bulb uses goes to heating the bulb; install compact fluorescent bulbs instead. Shutting down unused electronics also reduces heat (and your electricity costs). Use your dryer in the early morning or late evening, or use a clothesline instead.
Are you working on a large-scale addition or a project that requires removal or relocation of exterior walls? A high-quality house wrap, applied to the outside of exterior walls prior to siding installation, will keep your home cool and reduce your energy bills.
It uses a fraction of the electricity of a full-blown air-conditioning system. It's best suited for areas with hot summer days coupled with cool nights, such as the Pacific Northwest. All night, the fan pulls in outside air to cool the house. Many whole-house fans can be programmed to shut off during the warmest hours of the day.
Room air-conditioners are notorious energy hogs. To minimize the cost, choose an Energy Star-rated window unit properly sized for the room you wish to cool. Energy Star-qualified room air-conditioners use at least 10 percent less energy than conventional models.
Swamp coolers are popular in the Southwest because they add a comfortable level of humidity to dry air, are relatively inexpensive, use a quarter as much electricity as a standard unit, and they are easy to maintain. On the inside, water-soaked pads frame the unit. A fan blows hot outside air through the wet pads, cooling the air by about 20 degrees Fahrenheit as the water molecules evaporate. The cooled air is then blown into the house through a vent.
Planning to stay in your house for 10 or more years? Install a geothermal system. It harnesses the earth's natural thermal energy via buried pipes filled with a liquid similar to antifreeze. During the summer, it pulls out warm air and dissipates it through the pipes. During the winter, it works in reverse, bringing the earth's warmth to your house. According to the U.S. Environmental Protection Agency, geothermal systems save homeowners 20-50 percent in cooling costs and 30-70 percent in heating costs compared with conventional systems.