This is an old thread, but the following info is still valid:

My guess is that he'll burn-out the cooling unit (compressor motor) in no time. It was designed for operation for short periods to maintain cooler temps, not for full-time cooling on hotter days, let alone being outside... Speaking of hotter days, it's at the warmest part of the day that the unit would likely fail.
No ventilation, warm-n-moist air sitting there...not even close to optimal.

MJ...are you still around and did you give it a try?