mini split AC?

Larryjb · 06-28-2021, 05:56 PM

Everyone knows the side AC on older TM's is horribly inefficient and just doesn't cool well. Retrofitting with rooftop AC has many issues. Then I got the idea that a minisplit might work. It could be installed above the stove, and just lift into place if AC is desired.

Sure, it's not as convenient as turning a switch, but this could be a viable alternative. If I do anything it certainly won't be this year, but in case it sparks an idea for some one else with a older TM, here it is.

Larryjb · 06-28-2021, 06:12 PM

I just noticed that you need refrigerant lines to connect to the interior unit. A minisplit AC is probably a no go.

Shane826 · 06-29-2021, 10:38 AM

This idea comes up on the TrailManor Fans Facebook page as well. They quickly realize why it won’t really work. One guy even had a cargo carrier mocked up for the outside unit on the rear bumper.

**wbmiller3** · 06-29-2021, 11:24 AM

I'm looking for an answer too because my attempts to obtain or fab a drip pan for the side AC have all failed.

This weekend we camped in 100+ degree heat in southern Oklahoma. I used a 10K BTU portable room AC and ran the exhaust duct out the grille where the side AC used to sit. The unit is small enough that it can sit in front of the stove and we can still get by it.

If I could get the camper in the shade or the days were cloudy, it was manageable. The unit ran continuously and kept the interior temp in the low 80s. At night it worked great and could get down to the low 70s and high 60s. Since we are never at the campsite in the day, this was OK.

The first campsite did not have shade and there was no cloud cover, so it got up to the 90s in the camper during the day.

This is not my final answer, but it got us through the trip.

Shane826 · 06-29-2021, 11:29 AM

Do you still have the old drip tray? Can you post some pics, what’s it made of?

Larryjb · 06-29-2021, 12:21 PM

I used to think converting to rooftop AC was impractical. I'm beginning to reverse my thoughts on that, although a conversion would be quite involved. At the very least you would need to:
1) Enlarge the existing hole (assuming you are replacing the existing vent with an AC unit).
2) Inserting new wood bracing around the perimeter of the new opening.
3) Find a way to get 120V AC. This could be done by running a wire along the inside of the TM and plugging it in manually, or running Lumex wiring inside the shell. Running it inside the shell would be possible, but tricky.
4) It is possible you might have to change one or more of the torsion bars to support the weight. As an experiment, you could place a 100 lb weight along the center of the shell and see if you can adjust the existing torsion bars to compensate. I know I have lots of adjustment room left on my torsion bars so I believe it would be.

If the wood backing behind the bag seal of the front shell is in good condition, and considering TM now installs rooftop AC, it should support the weight of an AC unit. This was one of my original concerns, but I see you can get "lightweight" AC units that are now in the neighbourhood of 80 lbs.

Shane826 · 06-29-2021, 04:05 PM

Keep in mind there is no framing around the hole for the A/C on a TM anyway. Literally the only cross brace is the wood on the back edge where the bag seal attaches.

You’d need the larger hole and then a riser and skirt. Oh and the inner trim piece to go around the ceiling unit. As it just so happens, I have a brand new riser and skirt, and a perfectly good used interior trim piece. Let me know if you want to pull the trigger.

As for running the 120VAC cable, I’m thinking maybe it could be tucked into the bag seal, or run it up the interior wall alongside the bag seal with a piece of trim over it? Then use a hot poker to burrow a channel in the foam core to fish the cable through the roof?

I’m guessing you’re probably right in that it would require at least a pair of torsion bars swapped if not all four front bars. But if your TM currently has no A/C on the roof that’s pretty simple (can still be easy with A/C on the roof just heavier)…

Larryjb · 06-29-2021, 04:26 PM

That's interesting. When I removed my vent, there was a wooden frame inset into the shell. Somewhere I have a picture of it. I'd assume that such a wood frame would be absolutely necessary or the weight of the AC unit compress the aluminum skin into the foam. I'll post a picture later of what I mean by the wooden frame in case I was misinterpreted.

**wbmiller3** · 06-29-2021, 04:33 PM

Quote:

Originally Posted by Shane826

Do you still have the old drip tray? Can you post some pics, what’s it made of?

I have it, it's made of some semi-flexible plastic. The corners cracked from the AC jouncing around in it for 10+ years.

The problem I have is that the AC unit I have, that I replaced the factory one with, is literally the largest possible one that can fit in the existing space. I built a nice drip pan out of sheet metal, but I can't get it and the AC unit back into the space as one piece without breaking the hose connector off the bottom of the drip pan. I can't put the drip pan in, then place the AC unit, without bending down the walls of the drip pan.

Long term plan is to get a physically smaller AC unit, then I can use the sheet metal pan I made.

The portable AC unit I used on this last trip has a feature where it doesn't need a drain! I guess it internally evaporates the water and blows the vapor out the exhaust duct. I'd love to find that in a wall unit.

Anyway, after fighting with it last year, I just got sick of it. When I go back to it, I need to find a 1) physically small 2) high BTU 3)non drain wall unit. Easy, huh?

Shane826 · 06-29-2021, 04:36 PM

Larry- I follow what you’re saying. But remember the A/C isn’t mounted directly to the roof. It’s on a riser which really distributes the weight across the roof. And trust me, after the whole rigamarole I went through with saggy roof sections, I’ve confirmed multiple times there isn’t additional framing in the roof. Do I think there should be? Absolutely. Is there? Nope.