Attic fans with programmable thermostats and timers are easy to use, according to the EPA, because they often offer pre-programmed settings to regulate temperature. For the fans to function effectively, users must open at least some of the home's windows while the fans run.
Users can set attic fans to run once attic temperatures reach a certain point, or they can program the fans to run during specified hours. The fans also operate on manual switches, which can be helpful for users whose schedules prevent them from being home to open windows at specific times. The Green Building Advisor recommends using attic fans when outside temperatures dip below 80 degrees Fahrenheit.