I've just had an interesting idea. (Good or bad, only time will tell...) I've been planning to build a DIY swamp cooler for my trailer, but I've been concerned over the bulk, weight, water usage, and humidity.
It occurs to me, that I could build an A/C out of peltiers, fans and heat sinks. Other people have used the same idea to make camping coolers into electrically refrigerated coolers. No pumps or compressors, can be made almost any shape, lightweight, and would use very little power. If you're not familiar with peltiers, it's a flat, square sort of thing that if you run a current through it, one side will get hot, the other side will get cold. Often used for cooling processors. Here's an example of a rather powerful one:
https://www.banggood.com/TEC1-12726-400W-12V-Thermoelectric-Cooler-Peltier-Cooling-Plate-Module-p-1059508.html?rmmds=mywishlist&cur_warehouse=CNSo the cool half would be inside the camper, and the hot half would be on the other side of the wall. Like this:
I've also been making refinements to my CAD drawing. Got some better angles, and arcs, so I've got a nicer overall shape for what I hope the trailer will actually look like. I'm thinking of adding a medium sized portal window on the driver's side, as well as a fresh air intake near where my head will be when sleeping.
Measuring the dimensions, it looks like I can make each wall out of a 4x8 sheet of whatever. I've not decided yet exactly what the shell will be made of. Presently, I'm leaning toward two sheets of very thin plywood with really thin foam board sandwiched in between. Like 1.25". No final decisions yet though. Also, I'm thinking of what the door will look like. I've got that and an exhaust fan on the passenger side. If I find myself closer to the side of a road than I'd like, I'd rather open the door on the side of the trailer facing away from traffic.
Unfortunately, my CAD program doesn't capture or save to pictures well. But it looks great in the program, and you get the general idea. Anyway, I won't have a hatch on the back for a galley. This is a minimalist setup after all, so food, cooking gear etc. will be stored on the bike. I have been thinking of how I'll set up the interior though. With the shape of the trailer, raising the floor up about 6 inches will give me much more length to lie down. 6'2" vs. 5'6". I'm 5'10" so that will be nice. And I'll have a bit of storage underneath for electrical stuff, or whatever. I think a fold-down table will be sufficient to set a few things on while camping. I might put some tiny shelves on the sides for things like books or cell phone and chargers. Not more that a couple inches though.
I've got interior stuff in blue in the above picture. I'm not sure if I should put a flat wall in the front interior for hiding more electronics, or just leave it curved like the outside. I'll have to gather up all the wiring and stuff and see how I want it layed out before I can decide for sure. Maybe I'll do a half-wall and make it a shelf. I did leave enough room for head space both laying down and sitting up. I also checked out several other motorcycle trailer builds, and have found that the 38 or so inches of width I'll have on the inside should be plenty. One guy I know used a utility box on his sidecar frame (also a Ural) and build up basically a sleeping box from that. Now that's cramped! My little sleeping box will be luxury compared to that.
I have 3 more pages of build journals to read through here, and I've been getting ideas and inspiration from the builds and solutions that folks here have come up with. Great stuff! I also just realized that I'll need to have a 24V outlet for my cpap machine. Everything I've got now is based on 12V so I'll have to plan on a Volt booster at some point. I already need a bucker for the 5V stuff, so no big deal as long as I remember. I also want to charge a laptop or tablet in there, so I'll need a booster for whatever that uses. My little net book uses 19V for example, but that's an ancient Windows XP machine and I will be wanting to upgrade at some point. I'll have to collect all the electrical stuff and then design the battery based on what I need to power. That part is particularly exciting for me, as I'm a battery-math nerd!