sould work if you can tap off your heat and ac but that might be a problem because of the temps up and down stairs if your thermostat is in the living room and its hot as hell up in the attic it could be 72 downstairs whitch would make your air cut off if thats what its set two but the upstairs will probly hotter than the down stairs you might have to put it on 60 to get it cold enough in the attic get what im sayin

if that is the case you can always put an window unit in during the winter and a heater in the winter

ur probley better to try to tap off your ac system but your always gonna need constant air flow no matter what you do make it close to 75 thats perfect if you ask me!!!