Would it be bad if I let my air conditionning unit (window mount unit) running during the winter? I live in Canada,Quebec and -20C is pretty common even -30C
Just turn on the fan, no reason to run the AC unless you wanna remove moisture from the air. Oh and you are insane, I like cold air for my comp as much as anyone but I couldn't stand my room being that cold, heh. But yes, it would improve your temps of course, the cooler the ambient are the cooler all your temps will be.