Reading this made me wonder how a small AC unit like a PetCool might work in a SMB. Several teardrop trailers have these installed and they work well for them.
The question is how long would 380 watts run on the battery? While driving, it should be able to run off a 500 watt inverter and power off the alternator.
What is nice is that a 1000 watt generator should run this no problem too. My starcool needs the 2800 watt Microlite and will stall sometimes.
It is also works as 600 watt heater...
http://www.atrendyhome.com/hedoghoandai.html