Lots of helpful comments -- thanks! Although we do live in southern Calif, we live in the semi-humid part -- a few miles from the coast. (Can't afford a house on the beach!) But the a/c does reduce the humidity -- it puts out plenty of condensation that drips off the roof.
It is true that this a/c unit has no ducts -- it just has several small vents that can be opened or closed.
We could put up a baffle, but I am baffled about how to do that without destroying our already-limited headroom -- I am 6'3" and can't stand up under the a/c unit, although I can stand up in other parts of the trailer.
We tried the solution of closing most of the vents a couple of times, running the a/c for about 90 minutes at a stretch, during the hottest part of the afternoon. As far as I can tell, we did not experience any icing. We haven't tried running it during the whole night -- the temps where we live get down to about 70 at night, so we just leave the windows open.
Thanks again for all of your collective wisdom!
