Thought I'd do a quick write up on changing the AC unit in the front of a Casita
16' (2000), my latest project. The grammer isn't the greatest but I think it provides a fairly comprehensive idea of what is involved in replacing the AC. After rereading it I think I even made up a couple new words!
Remove floor of closet by lifting and removing, I just worked my hand behind one of the sides lifted and worked it out. Next I removed the “cover” from the airbox between the AC and trailer. First thing to do is remove the screws from the cover top. The inside (underneath the top) of the airbox cover is siliconed to create a seal, I used a wood chisel to jam under the cover to break through the caulk and then moved the chisel over a little and did it again until the caulk was totally broken around the cover. I then used a box cutter to cut the caulk that runs along the outside top of the cover against the front wall of the trailer. At this point the cover should come off without too much effort. I then removed the 2x2 that is caulked on top of the back of the AC. I then removed the four screws for the brackets (which extend from the front wall of the trailer) on the top of the AC. Next you’ll need to cut the caulk around the backside of the AC (The two sides and bottom of the back). Next remove the bar holding the AC in the front with a screw driver and remove the decorative trim around the front of the unit. At this point the AC with a little effort should slide out through the front. You might try lifting the back of the AC to “break” any existing caulk. Clean up all the old caulk you had to cut or break so you’ll have a clean surface for the new caulk during the install.
There are some mods that probably should be done on the new AC before installing. The first was to remove a few “brackets” that are used to fit in a window groove on the bottom front of the AC. Second mod to the AC was to silicone the sides and a little around the back where the cover of the AC meets the bottom, in this area there is a pan that collects water, that is what you’ll be siliconing so all the water will want to flow out the back of the AC. Third mod was to provide a channel or spout so the water would tend to run out the same area of the AC rather then haphazardly out the rear (see old unit).
Installing new AC:
On the install you might have to do some fabrication if the unit is not almost the exact same size. Though there are some mechanical attachments, the AC unit is really held tight in place by the caulking that seals the airbox. The AC I was installing was 1 ½ inches narrower so I used a couple pieces of 1x2 to fill in the gap on both sides of the fiberglass airbox. I used wood because I felt that it needed to be a rigid and solid so the caulk and the tight squeeze would hold the AC from shifting. Next slide the AC in and position it so the front sticks out correctly and the back fits into the topless airbox. Make sure the back of the AC is lower than the front for drainage. You might need to do some fabrication on the front top support depending on your AC choice. I then attached the two brackets and four screws on the AC top. Next I attached the front top support bracket. After I had the brackets in place I siliconed the back sides and bottom of the AC to the airbox. When I siliconed the back I created a little channel using silicone (like the original) to help guide the water out to the front vent . Next I siliconed a 2x2 on top of the AC, so the top of the 2x2 was now level with the top edges of the airbox. Instead of totally siliconing the top back on I used a foam gasket material along the top edge of the airbox and AC (top of the 2x2) and added a few extra screws and used some metal duct tape on the outside of the joint. I next installed the top and screws and then siliconed along the back of the front where it meets the front wall of the trailer. Next I put the floor of the closet back in and trimmed out around the front of the AC (molding). Next plug it in turn it on and chill out!
The whole process took about 5 hours and I did it by myself. If you can lift 60lbs relatively easy you shouldn’t have a problem. Now that I’ve done it once I could probably do it in under three………. I hope that will be unnecessary. I did have all the tools on hand that I needed, I used five different screwdriver heads (Phillips, straight, the square “trim” head, and two that were the same type but different size that I can’t really figure a good way to describe), Box cutter, wood chisel, caulking gun, a couple misc. items and what I needed to cut the trim.
One thing I’m thinking about doing is when I get a Turbo Maxx fan (a Fantastic with a special Maxx vent cover would also work) is installing a couple small vents that close on both sides of the electrical
outlet for the AC. That would allow me to open those vents and draw air through the side and bottom vents intended for the AC. This would provide a fresh air source for the Turbo Maxx when it is raining too hard to have a window open.