Heating and cooling can be an issue in many RVs. In most cases, it is all or nothing, heat or cool the whole space or not. Heating is easy to solve. many of us use a small space heater to just heat the room we are in. Not only does that work well, it uses camp electricity, not your own propane.
Cooling is a bigger issue. Again you have to cool the whole rig, not just the room you are in. The compressor is noisy, especially at night, and hogs electricity, especially on a 30 amp service.
This video has an interesting solution, a DIY air conditioner, or more properly an air cooler. It does not dehumidify, but it does cool.
DIY Air Conditioner From a 5 Gallon Bucket for Under $25
So I tried it, and it WORKS.
Things to know. Don't use a Home Depot bucket. Lids are atrocious. ( I will be replacing mine.) The video suggests a bait bucket or similar as the inner insulation. I went to the dollar store and bought a sheet of corrugated plastic cardboard, the kind you use for signs.. I cut it into strips, then taped them together to get onto that round inner wall, cutting out slots for the vents. I cut a bottom piece for the floor. For the vents pipes I wound tape around the inner tip to tighten and seal the round vents to the pail. This will give plenty of insulation for the time it will be used. I may caulk these later.
I cut the hole on top, and placed a small fan to push the air over the iced bottles. Each time I need it, I place 2 or 3 small bottles of frozen water into the pail, then put the lid and fan on.
Note, for the bedroom at night, I place the AC on a footstool near the door, and place a big fan behind it to blow the air right into the room. Very low fan noise, cool air, and small electrical load.