Most Efficient Air-Conditioner Temperature

Thermostat Setting

• For the most efficient use of your air conditioner, the thermostat should be set no lower than 78 degrees F when you're at home. When you're away, the thermostat should be set several degrees higher, since you don't need to cool an empty house. Also, there's a general misconception that lowering the temperature cools the home quickly; however, BuyEnergyEfficient.com states that it will take the same amount of time to reach 78 degrees F as it would to reach 70 degrees F.

Location

• For maximum efficiency, your central air-conditioning unit should be located on the north side of your home -- away from the sun. If not, plant trees and shrubs to shade the unit and allow it to operate at peak performance. Don't place thermostats in direct sunlight and doorways, near windows, under skylights or in draft areas, as these locations will affect efficiency. Also, avoid setting TVs or lamps near the thermostat, as the thermostat will sense heat from these items and prolong the time that the air conditioner needs to operate.

Temperature Control

• Another way to keep your temperature at an efficient level is to use ceiling fans to help circulate air and cool rooms. The Department of Energy states that using a ceiling fan will allow you to raise the thermostat by 4 degrees F, while experiencing the same level of comfort. However, "fans cool people, not rooms," so turn the ceiling fan off when no one is in the room. Use the bathroom fan to remove the heat and humid air produced while showering or bathing.

Other Considerations

• Keeping curtains closed during the day helps the house maintain cool air, and opening them at night allows the heat to escape. Also, change your air filter on a regular basis, as a dirty filter can decrease your air conditioner's energy efficiency from 5 percent to 15 percent. In addition, ensure your air conditioner's registers are free from dust accumulation, which can also affect efficiency.