Looks Like a Duct

Summer is terrible. I don't really mind getting hot and sweaty but I'd rather not if that's my option. My need to remedy this falls in nicely with planning the insulation and storage in the camper interior as well as the steps. So the plan has always been this vague notion of putting a cheap window A/C unit in a box and running duct work to the camper.

Somehow.

This is how, really:

Start with a $25 air conditioner I got on craigslist. I already took off the front cowl, thermostat knob and cut the cord.

The bottom portion with the coil is the fan return. It sucks air through the coil and spits cold air out the top. The duct is .08" thick aluminum, which is way too thick for the brake in the lab, so I did this with a lot of clamping and hammering. It came out pretty rough but it's functional. It separates the air return from the outlet and leads to a handy 4" round duct.

The top half came out way better. I used .02" thick galvanized steel sheet and , anyway, it's a much more simple shape. 

Looking from the top, the fan is wrapped in a box of styrofoam insulation . You can make out the lip of the bottom duct resting on the insulation and then the outlet duct. The very top of the box has a 2" lip all around and it's basically open. This is so I can see where I need gasketing and check the fit and access the A/C controls.

The whole thing is then capped by a formed (deep draw) pan. There will be a gasket around the top and the pan will squeeze down on it. The A/C will be mounted on a steel angle shelf integrated onto the steps and then a cargo strap will hold the top on. 

Warm air gets sucked in the bottom, cold air shoots out the top.

Shmancy!

The interior of all the sheet metal will be sprayed down with rubber: that spray seal stuff. The idea is that it'll both seal the corners and seams and will insulate the metal to reduce heat exchange and keep this a convection only system.