I have a 18,000 btu dankin with two heads in my bus. It is 220 ac and i run it on 120 vac using a 2:1 transformer. My experience has been good except the transformer. I purchased a China model double the size I needed, but it didn't last. I now have an industrial transformer and have had no problems. If the outside temperature is moderate, I can operate off the bus alternator and inverter. Otherwise I use a Honda 3500 generator.
I just finished installing a 12,000 BTU Mr. Cool in our 102D3. Needed a unit that ran on 120V and most units I looked at were 220v so settled on the Mr. Cool. Installation went very well, no leaks. Very quiet unit.