Most air conditioners are designed to operate and cool interior spaces when the exterior temperatures are 60 degrees Fahrenheit or warmer. Use of the air conditioner when the outdoor temperature is below 60 degrees Fahrenheit is not recommended because frost may develop on the evaporator coils, which can hamper or damage the air conditioner. In addition, the energy consumption increases when the temperature is not warm but the air conditioner is in use. Using the air conditioner when the outdoor temperature is below 60 degrees is possible, however, with a few adjustments.
Set the thermostat to “Fan Only” or “Fan.”
Move the “Fresh Air/Exhaust” control to “Fresh Air” if the air conditioner has a fresh air/exhaust control. Set the thermostat to “Cool” if there is no fresh air/exhaust option.
Adjust the temperature to at least 78 degrees Fahrenheit for the best energy consumption.
Turn off the air conditioner when the outdoor temperature drops to freezing or below, which is 32 degrees Fahrenheit. Operating the air conditioner when the ambient temperature is below freezing can damage the unit.
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