I am a huge fan of the mini split units, and you can get a smaller one to fit in the trailer, no problem. The remote thermal transfer unit is the only thing you'd have to consider, but I've seen a few genius methods to mount one.
No doubt about the insulation. That said, at this stage it is not feasible to do anything about that. When/if I need to rip out the interior, I'll look into replacing it.
If I go that route, what I have in mind is one of the units like they install on camper vans or truck sleeper cabs. 12v system instead of 110v, and the outside unit is designed to mount under body. Would tuck right up into the frame rails underneath the camper. Be out of the way and protected, also might be more efficient being in the shade under the camper.
If I built up the available battery capacity it could potentially be run overnight off batteries alone. Not much need for that at a site with electrical hookups, but if "boondocking" it would allow for running generator during the day to charge batteries and shut off at night for quiet.
When I mentioned a lithium battery bank earlier,that is kind of what I had in mind. At that point the only thing 110v would be the microwave.
Just as a reference point, I have a 5000btu in a room that's 8'x10' 7ft tall on the 2nd floor. Saturday you could feel the temperature difference between your waist in a chair and your head. It was 86* outside and high 70s at the ceiling but low 60s about halfway down...
That may be a part of the problem, and something that I had considered as well. Heat rises, cold sinks. The window unit is down at floor level, the coldest part of the room.
Might work better if the unit were set up higher on the wall. Might work better if there was a vent in the ceiling to draw the hot air out. Unfortunately it's not exactly very practical to rebuild everything just to do those things. That is what it would turn into, a full gut and rebuild.
If I do the mini split deal, the inside part will be up high near the ceiling which might help. In the interim, some of those newer window units have a remote thermostat in the remote. The idea is that it judges room temperature on location of remote instead of location of the unit. If I use one of those and store the remote high on the opposite corner for the camper...
Were the attached awnings / tent room set up?
No. They could definitely help, but I want to get things as good as I can in the worst conditions possible. Well, worst conditions I'm likely to go in, if it's too bad I'm staying home. It was intentionally parked in direct sunlight all day with no covering, I wanted to see how it would perform before taking it out somewhere.
Once I get things situated it's going to be parked under a carport at home, but I'm not really going to be using it there. When camping I'm going to try to select shady spots to setup in, but you don't always get the choice.
On the list of wants is a roof rack. That's largely to throw a kayak or canoe up there. I also want it for a structure to string up a tarp covering and create an air gap between that and the roof. The solar panels mentioned previously also was related to this. Those on the roof rack would create a barrier between the sun and roof like a tarp, and have the bonus of charging the batteries. Solar isn't a pressing concern or desire, just an idea, and may not be worth the added weight.
