Another way to cut your AC expense is to install an attic gable fan. Below is an example of an install a reader sent us from the Philadelphia area. This install was done with a fan that the home owner already had and a new WIN100 outlet controlled thermostat from Lux Products as seen in this photo.
The home owner set the WIN100 to kick on the attic fan at 90 degree. Once the gable fan starts running, it pushes super hot air out of the attic space. The home owner has reported his 2nd floor is now much cooler and the central air does not have to run as much; also this has helped better “BALANCE” the building temperature; for prior to installing the gable fan, the 1st floor was cool and the 2nd floor was always much warmer.