I'm back after an extended absence.. In the midst of that moving trip three weeks ago the bus engine died. Fortunately it had just enough speed to coast off the interstate at a conveniently-located off-ramp -- it happened in a construction zone where the shoulder was adequate only for pulling off a very skinny motorcycle. Full-size bus? Forget it!
Anyway.. based on the somewhat-favorable results on the test with the tarp curtain, I made a wall from OSB and stuck that A/C through it. I acquired some large cardboard from appliance boxes and used it to make a template of the roof and wall shape, then transferred it to the OSB. Sorry, it seems that I don't have any pictures of the OSB now. I'll add those later. For the first step I mounted the cardboard on a piece of 1x2 and got some help holding it in place. Then I held a pencil at a fixed position on the straight edge as shown and slid the pair toward the left, following the curvature of the roof and transferring it to the cardboard. I cut along that line, then moved the cardboard up and did a similar process to copy the shape of the wall.
Weather was cooler for the trip than it had been in that stretch of scorcher days when I did the tarp test. The A/C did fairly well. I did discover that the bus has more air infiltration than I would have guessed/hoped! That continual air change definitely affects the ability to cool the space. In any case, it did make things more comfortable. I'm glad I had it along.
For power, I built a little hitch mount for the EU2000. It's a piece of 2" receiver tube with a pair of 1" angle steel perpendicular to it, aligned so that the steel angle runs under the feet of the generator. I removed the rubber feet from the generator and built a spring mount: an ordinary compression spring, a washer with a little notch cut from its outside edge, a bolt welded to the washer. OK, four of the springs and 8 of the bolt thing. Rather than sit on its feet, the generator sat on these four compression springs. It stayed attached and it kept running the whole trip.
One thing I did discover: there are some ways of shutting down an A/C which can make it exceptionally hard to re-start on a barely-big-enough generator. Pushing the "power" button on this unit is one such method: I shut it down while we loaded stuff into the bus for 30-45 minutes, and then the generator couldn't re-start it. Finally it occurred to me to turn the A/C on and quickly switch it to fan-only mode. After running that way for a while.. 10 minutes, maybe (?) .. it re-started normally. My theory is that the extra air flow especially on the condenser helped cool things and reduce pressures so that the compressor could start more easily. This seems to be the same behavior as happens when the A/C automatically cycles the compressor when (if!
) the temperature set point is achieved.