Thanks for the feedback Smitty.
In regards to the 50 gal WVO drums in the back, they will be in and out of the bus depending on my need. For long trips they will be used for collecting raw WVO from restaurants. They need to be upright for reasons I won't elaborate on here, so I can't mount them underneath the bus. So the only option is in the garage, or build a back porch. I don't want the bus to be any longer than it is. Plus, I want to be a bit incognito about my WVO burnin'.
Some states are a bit uptight about that. The arrangement of the barrels in the garage is uncertain at this point. I need to see them in the bus to really get a sense of the space. I'll try to put them somewhere where I can use the space above them for storage.
So if I have the window A/C unit sitting in a cabinet that is completely insulated from the inside of the bus, and vented through a window, wouldn't that solve the problem of venting my cooled air? I wish I could find the example I found before - I think it was somewhere in the gallery, but I can't remember which bus. I can't really mount the A/C in the rear of the bus, because I'd just be cooling my garage, which I want to be insulated from the rest of the bus due to the stink of the WVO.