This will allow the ac to only stick out about 2"
on the exterior.
Here the roof vent can be seen
Here is the almost enclosed ac
Great idea & post on the window ac unit using a refrigerator roof vent, with a small unit like that one could even install 2 smaller 5,000 But ac's into a larger trailer.
I would guess that the fan in the ac has enough suction on the rear end ?
Maybe the roof vent is like this model approx. ?
I have another idea for a side vent that may also work.
I would also assume there is some kind of pan to drain the water to the exterior or ??
Find the roof vent at this link