Air Conditioners

Buying a bigger room air-conditioning unit won't necessarily make you feel more comfortable during the hot summer months. In fact, a room air conditioner that's too big for the area it is supposed to cool will perform less efficiently and less effectively than a smaller, properly sized unit.

Sizing is equally important for central air-conditioning systems, which need to be sized by professionals. If you have a central air system in your home, set the fan to shut off at the same time as the cooling unit (compressor). In other words, don't use the system's central fan to provide circulation, but instead use circulating fans in individual rooms.

Cooling Tips

• Whole-house fans help cool your home by pulling cool air through the house and exhausting warm air through the attic.
• Set your thermostat as high as comfortably possible in the summer. The smaller the difference between the indoor and outdoor temperatures, the lower your overall cooling bill will be.
• Avoid setting your thermostat at a colder setting than normal when you turn on your air conditioner. It will not cool your home any faster and could result in excessive cooling and, therefore, unnecessary expense.
• Consider using an interior fan in conjunction with your window air conditioner to spread the cooled air more effectively through your home without greatly increasing your power use.
• Avoid placing lamps or TV sets near your air-conditioning thermostat. The thermostat senses heat from these appliances, which can cause the air conditioner to run longer than necessary.
• Plant trees or shrubs to shade air conditioning units but not to block the airflow. Place your room air conditioner on the north side of the house. A unit operating in the shade uses as much as 10% less electricity than the same one operating in the sun.

Long-Term Savings Tips

• If your air conditioner is old, consider purchasing a new, energy-efficient model. You could save up to 50% on your utility bill for cooling. Look for the ENERGY STAR and EnergyGuide labels. The shopping guide in the back of this booklet will help you find the right size unit for your needs.
• Consider installing a whole-house fan or evaporative cooler if appropriate for your climate. Check out http://www.energysavers.gov/ for more information on efficient cooling.

About Energy Savers

The Energy Savers web site shows you how easy it is to reduce your energy use at home and on the road. The easy, practical solutions for saving energy include tips you can use today, throughout your home—from the roof, walls, and insulation that enclose it to the appliances and lights inside. To learn more about U.S. Department of Energy programs in energy efficiency and renewable energy, visit the Office of Energy Efficiency and Renewable Energy's web site.