Unfortunately the bunk portion of my camper, particularly the lower bunk doesn't get much air flow. I purchased a clip on 120V fan for my son to use. We clip it to the rail of the top bunk and it blows cool air in there. My next project will be insulating under his bunk as it is a storage area and allows heat to seep in. My suggestion would be to try and locate fans that maybe you could mount, or see if one of those portable air conditioners would work. My air has failed 4 times(Dometic) and once it was just before a trip. I rigged a portable unit's output to the stove vent and tested with that. Worked OK but my dealer was able to get a replacement right before I left. I've thought about fixing a exhaust outlet for the portable unit through the rear storage compartment just in case. Portable unit cost me about $420 and its on wheels.
2015 Cherokee Limited 274DBH
2000 F250 CC SD V10 4X4 8' bed, 4:30 gears, SCT X3
2007 Mustang Convertible V6 - Lots of GT mods
1965 Mustang Coupe I6, 3 spd. manual
1963 Thunderbird Landau 390