Re: bedroom air
4KW should run the AC and most other loads, although you might have a problem using a high current load like the microwave when the AC wants to start. I've seen trailers with 'window' type air conditioners sticking out, but I don't know how well that would work on a unit which was moved much; I suspect it would be problematical. A roof top unit designed for a motorhome would probably be a better choice. Be aware of how much, if any, height it would add to your unit.