Even though the mercury says 90* even as the sun begins to set, I was wondering about what to do for a northeast winter? I have a Trane attic system (AC only). Do I just turn the thermostat off? (seperate from heat thermostat). I was told by the installer that I shouldnt shut the compressor's outside disconnect box off or the circuit breaker because my compressor has some type of warmer (Trane XL14i). Any info would be helpful.