We ordered this AC to replaces a 6000btu AC in our 21ft Roadtrek motorhome.  It seems to cool down the back sleeping area as long as I have it closed off from the rest of the inside space. I also use a little fan to blow the air back into the bed area. I think it. Is definitely working better but not great. Some of our problem is. Design issue with the Roadtreck itself. I have noticed. That the makers have gone to a top mounted AC. Wise I think.  Still it is the best we could get as we had a space constraint. I would buy it again. Thank you