I just recently replaced my attic fan and need a recommendation as to what temperature setting to use. The range on the fan is from +50 to +130 degrees F.

 

Wherever you set it, it will run constantly during the peak of the day. So what you are setting is, when it will start in the morning and when it will stop in the evening. Since it would not be good to have it running 24/7, somewhere around the 100º mark should be fine. At 90º it could run a lot and that would be wasted energy as the benefits would not be noticed over say 100º or 110º.

What you are preventing is the build up of heat, say 160º, and the long time it takes for natural ventilation to bring that down in the evening. Take some time and seal as many leaks as you can from the house into the attic, as that fan will also be pulling conditioned air from the house. Here is a link on air sealing to help you find all of those hidden spots. The link opens slow, but it is good.
http://www.efficiencyvermont.com/ste...ide_062507.pdf

Bud

 

In addition to stopping the leaks from inside the house, make sure that you have the correct amount of inlet area to allow proper airflow.