Originally Posted by stanw909
I think the louvers he proposed would provide adequate ventilation.
You might be right, but window units are designed to operate with condenser sitting in free air, just like residential central air conditioners and other condensing units. On cooler days you might not notice the issue, but on hot days if you get any recirculation of air the AC could overheat and/or lose capacity.
Manufacturers that use window units (and I installed one inside my van, so I have nothing at all against them) make an effort to segregate the air flow as much as possible. Look closely at these vans and you'll see baffles or some kind of plenum. Lately I've seen window ACs used more often on small trailers too to keep OAH lower and also reduce cost, and they too segregate the air streams as much as possible.
I'd use one again if I were building another myself, but I would not install it like you have it due to expectation that air could recirculate around the condenser. It might not even happen all the time but only when wind is blowing just right (I'd guess slight direct wind towards back of van might be worse-case scenario. Exhaust air could be pushed back to suction too easily.
Just a second opinion. Good luck with your project, looks cool.