Do any of the RV's manage to keep you cool when the temperatures are at or above 100? Have an older 31' 5er with one roof top A/C, and an additional "portable A/C" in the front bedroom. I'd say at bes...
If you have a the "Quick Cool" feature where you can switch from the air going thru duct work to having it "dump" say into main living area, might want to just have it dump into living area during the day., Sure it may not reach temp you have it set at, but probly more efficient than running thru duct work. Just a thought.