Two thoughts: in a refrigerated truck trailer the reefer unit is on the front wall, outside. Inside the trailer the reefer is connected to a cloth duct that runs the entire length of the trailer, and has cloth vents that are held shut with velcro and can be opened or closed, to direct the air where you want.
Any A/C tech will tell you that ideally the condenser should be located in a shady spot, yet on trailers they are located in the hottest and most shadeless spot possible, the roof. Mitsubishi makes a 110 volt split system for cooling a small room. The main part of it is outside; there are two approximately 2" diameter lines that carry the cooled freon thru the wall and to the inside cooling unit. The inside unit is very small (about the size of the controls and vents on a window A/C) and can be mounted directly to the wall. If someone could come up with a way to mount the outdoor half on the tongue of the trailer I think you'd have a great system.