No cars, or gas stuff, however a whole bunch of junk.
Initially, the idea was to use it in my basement / downstairs room so that I wouldn't need to heat it during the winter.
However, the noise problem is big, plus, it currently warms the room to around 32 - 35 deg C (which is approx 10 deg higher than ambient). Now, in winter, that room generally drops down to about 17 - 18 without warming it up, so, with the servers, it would still get it warmed to around 27 - 28 in winter, waaaay to high.
As for the exhaust coming back into the house, I would have to insulate the duct for the length of about 5 meters from the garage back into the house. I'm not sure whether that is feasible, or whether the loss would be too great.
I do agree that I am "wasting" a whole bunch of potential heat, and I hate that, but, don't know what I can do, unless I maybe plant some tomatoes and maybe some peppers and cucumbers in the garage over winter, and throw in some lights to see whether they can grow (now that it will be warm).