Don't put your compressor outside, depending on the relative-humidity and time of day, all you'll be doing is pumping water through your lines.
The best thing you can do is what I did, I actually put the compressor inside my HOUSE... in it's own little room with some foam on the walls and rubber under the feet, but the doorway has cutouts for two 20"x20" furnace-filters.
Sure, it's louder for those in the house, but it's quiet outside, and it's quiet in the garage. Plus, the compressor gets a constant supply of cool and dry air.
Note: you'll need a forgiving wife.
Oh, almost forgot... I ran a 1hp roll-around comressor once a few years ago on an Olds Cutlass I was redoing the trunk on...
I had the compressor about 5-feet from where I was shooting (wasn't shooting much, so I didn't worry about the comressor). BAD MOVE having it in the garage with you while you paint... the thinner in the paint ended up dissolving the insulation on the motor's windings...
Fortunately for me, it threw the 30-amp breaker before blasting everything in the garage. Hope it helps!