What Temperature Should an Attic Fan Be Set At?

Attic fans draw cooler outside air into the hot attic area through attic vents located either on the roof, or on the wall near the gable, to reduce the space's temperature. Lowering the temperature in the attic can lower the temperature in the rest of the home, reducing the amount of time the home's air conditioner spends running.

Most attic fans operate with a thermostat that automatically turns the fan on and off based on a temperature the homeowner sets. Most manufacturers and contractors recommend a temperature setting between 100 and 110 degrees Fahrenheit. In particularly hot climates, set the temperature higher to keep the fan from running for extended periods of time. In areas with high humidity, homeowners should install a humidistat -- which will start the fan when a certain humidity level is reached -- to reduce the amount of moisture in the attic, limiting mold and rot.