A/C is a good idea as long as it doesnt change the intended air movement. I think 20 C is perfectly good, just dont overclock it. Putting it outside is a risky way
I have put mine in the cellar. I must say I'm lucky - my cellar has electrical lines and it is cool, about 16C. Besides, no noise in the apartment.
Not really looking forward to overclock it though. You know what they say: "better safe than sorry"!Cheers,
Stephen