Sizing Your Air-Conditioning Unit

It might surprise you, but a bigger air-conditioning unit won’t necessarily make you feel more comfortable during the hot summer months. An oversized room air conditioner will perform less efficiently and less effectively than a properly sized unit. This is because smaller units that run for longer periods maintain a more constant room temperature and remove excess humidity more effectively.

Central Air-Conditioning Systems

Proper sizing is equally crucial for central air-conditioning systems, which should be sized by professionals. For optimal efficiency, set the fan to shut off simultaneously with the cooling unit (compressor). Avoid using the system’s central fan for circulation; instead, use circulating fans in individual rooms.

Cooling Tips

• Whole-House Fans: These fans help cool your home by pulling in cool air and exhausting warm air through the attic. They work best when operated at night and when outside air is cooler than inside.

• Thermostat Settings: Set your thermostat as high as comfortably possible in the summer. The smaller the difference between indoor and outdoor temperatures, the lower your cooling bill will be. Don’t set the thermostat colder than normal when you turn on your air conditioner—it won’t cool your home faster and may lead to unnecessary expense.

• Interior Fans: Use an interior fan along with your window air conditioner to spread cooled air more effectively without significantly increasing power use.

• Thermostat Placement: Avoid placing lamps or TV sets near your thermostat. The heat from these appliances can cause the air conditioner to run longer than necessary.

• Shade Your Unit: Place your room air conditioner on the north side of the house and shade it with trees or shrubs without blocking airflow. Units operating in the shade can use up to 10% less electricity.

• Insulation and Sealing: Insulation and sealing air leaks improve energy performance in the summer by keeping cool air inside.

Long-Term Savings Tip

If your air conditioner is old, consider purchasing a new, energy-efficient model. New units can save up to 50% on your utility bill for cooling. Look for the ENERGY STAR and EnergyGuide labels to find the right size unit for your needs.

Stay cool and save energy with these practical tips!