Whe we were out west last summer outside a Cabella's in one of their
pavement campgrounds it was 105' F. I went into a local Walmart bought a
5,000btu (might have been a little but bigger) window unit. I used the
cardboard from the box,foam strips,some duct tape,and a ratchet strap with
hooks on the end.
I heard from several of the "huge" rv's it looked Hillbilly**.  It worked
very well and I ended up using it on the rest of the trip. The strap hooked
to the raingutter and a bungee cord down to the rim was all that was needed
to hold it into place. I"d pop it off and put it into my inlaws airstream
trailer so I didn't even have to deal with hauling it around. I"ll start
carrying it again when I get my trailer built. I will replace the cardboard
with sunbrella though!!! Maybe...

Bill

**No offense is meant to the hillbilly's on this list. I only use the
word to quote what was said about me and my a/c installation.  I would never
use the term "hillbilly" to describe a person that is very creative with
their repairs,mods,and way of life**