Attic Fan Thermostat Is It Worth The Savings In Energy Cost To Install A Gable Fan For My Attic?

Is it worth the savings in energy cost to install a gable fan for my attic? - attic fan thermostat

I went there, and install a bathroom fan and it was ridiculously hot. There are torn pieces at each end of attic vents, and on every 10-15 meters below the integrated channel. There are approximately 1 m in isolation to blow. I thought about installing a fan connected to a pinion thermostat. If I do so, at what temperature should I set the thermostat? And if the fan air in or out? I live in Louisville, KY.