Check to see if your air-conditioner, washing machine, dryer, freezer, or refrigerator has an Energy Star label located on its back or side. If it does, go to www.energystar.gov, click on “Special Offers,” plug in your ZIP code, and see what specials and rebates may be available in your area. For instance, if you live in San Diego, you could qualify for a rebate of up to $175 for a clothes washer. If you live in Montpelier, Vermont, the rebate might be up to $50.

Heat or cool air lost through your windows can account for 10 to 25 percent of your energy bill. If you don’t have them already, install storm windows to reduce air loss. If you want to know how much they would cost and how much energy they would save, go to www.efficientwindows.org, a site sponsored by the U.S. Department of Energy. You can then set up a free installation estimate with Sears (www.sears.com) or Home Depot (www.homedepot.com).

Heating
Lower your hot-water-heater temperature 10 degrees, but make sure it’s not lower than 120 degrees. (Lower temperatures won’t effectively clean clothes or dishes or eliminate bacteria from the skin.) Also, wrap your heater in insulation. Doing both these tasks can reduce a yearly bill by 5 percent or more.

Identify any seams, cracks, or openings in ceilings, walls, or floors that are letting cold outside air into your home, forcing your system to work harder and use more energy. Sealing up air leaks can shave 15 to 50 percent off energy costs.

Clear baseboard registers and radiators of dust and clutter. Make sure they’re not blocked by furniture, carpeting, or drapes.

Have a green thumb? You can deflect winter winds by planting evergreen trees or shrubs on the north side of your home. While you’re at it, plant shrubs to shade your air-conditioning unit. A unit in the shade uses 10 percent less electricity than one operating in the sun.

Cooling
To keep your costs in check this summer, first find a professional contractor and make an appointment to have your window or central air-conditioning unit cleaned and inspected. (Try the North American Technician Excellence website at www.natex.org, which is endorsed by the U.S. Energy Department.) Feeling do-it-yourself empowered? Check your air-conditioner’s filters and coils and look for dust buildup that can restrict airflow and place stress on the system. This added stress creates wear and tear on the unit and increases energy use and operating costs.

Set the thermostat on your air-conditioner as high as you can stand. If you have a thermostat, try 78 degrees. Why? Each degree below 78 adds 6 percent to your cooling costs. Use fans to move the air inside your home. This gives the sensation that it is 5 degrees cooler than the actual temperature.

If you're in the market for a new air-conditioning unit this summer, consider this: “The biggest mistake people make is thinking that they are saving by buying an oversize unit,” says Michael Lowndes, spokesperson for the Long Island Power Authority, in Uniondale, New York. “A large unit can be just as inefficient as a small unit.” To avoid this misstep, take your room measurements and the location where the unit will be placed with you to the store where you will make the purchase. According to Lowndes, a properly positioned and maintained window unit can shave $50 to $70 a month in electricity costs.