Another Mini-Split discussion

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Another Mini-Split discussion

March 21, 2023, 01:56:01 pm

I've seen several threads on mini-splits in GVs as well as videos in a 270(?). I am considering a mini-split system in my 320. Occasional research on the subject has come up with a few different options.

1. Single unit mini-split up front. Possibly mounted above the dash in the cabinet area where the old VCR is. Possibly mounted in one of the cabinets in the center of the living area. I don't like the idea of a unit sticking out of the cabinet or removal of the cabinet door. Also, running the wiring and refrigerant lines to these areas doesn't sound great.

2. Dual unit mini-split where existing roof airs are. These units are between 20-24 inches wide. The existing ones are around 15 inches wide. These are also non-ducted and spew air only from the bottom. Cutting steel may be involved to fit these correctly and running lines would be rather cumbersome and potentially go over the roof.

3. Concealed duct-able mini-split. This is an interesting option. The inside unit can be placed on the ceiling, under the couch, in the closet, etc and new ducting can be placed through the coach. In my WTFE, it could possibly be placed below the closet in the bathroom and have ducts going to the bedroom, bathroom, kitchen, and living space without hanging a unit. it could also go into a bay with ducts run up into the interior.

Concealed Ducted Mini Split Air Conditioner Heat Pumps - MiniSplits4Less

I figure an 18k unit should likely be enough to cool down the whole space and use a lot less electric than the roof airs. The other issue is how loud these roof airs are. the mini-split is less than 40 db.

Have any of ya'll considered the different options in mini-splits? This unit is also 230v single phase, so I'll also need to figure that out... maybe a separate inverter just for that.

Re: Another Mini-Split discussion

Reply #1 – March 21, 2023, 02:28:02 pm

I've been going through the same decision process for my GV. I thought about the roof-mounted units but ultimately decided I don't want to expand the hole sizes in the roof. Right now I'm leaning towards a dual zone mini split with 9k BTU wall-mounted units in the living room and bedroom. I am not sure if I can get a pre-charged unit with enough capacity for a line all the way to the bedroom from the nose of the coach so that's still an unknown. I don't know enough about mini splits yet to know if that's a big deal.

I don't think I want to take the chance of only having one unit in the living room. I hate being hot while sleeping and for those 90+ degree days, I think it'll be worth the extra hassle of running the second unit there. A bonus of having units in each half of the coach is that I'll have much quieter heating than the furnaces when I have shore power

I don't recall what I have for a main power panel in the GV (it's still in phoenix) but I'm hoping I can run 220v from there to power the unit.

Re: Another Mini-Split discussion

Reply #2 – March 21, 2023, 03:28:30 pm

Have you looked into the concealed units? With one of these units, you can shoot ducts to the water tanks, battery bay (if you need it), and each area of the coach. It's pretty much just a giant hole in the side of the indoor unit that attaches to a metal box with 4 or so holes that'll attach to ducts. In my case, the ducts can go to new holes i punch out under the kitchen sink cabinets, under the bathroom closet, under the bedroom drawers, and somewhere up front by the captain's chair. The indoor unit can go in a bay on the ceiling if I want.

For electric on dual units or something like a concealed unit.. It's 230v single phase. I believe this can be achieved with a double pole breaker on a normal fuse panel. Us RVers don't have normal fuse panels and each leg is separated. In this case, you need something like a Quattro 5000 120v with an auto transformer to achieve 230v single phase. This will allow the unit to be powered from the grid as well. ORR you can get a separate 230v single phase inverter like a Phoenix smart inverter 24/3000 230v. in this case, the inverter will power the minisplit from battery power. your 120v inverter will need to feed the batteries and in turn, the 230v will be powered when connected to the grid.

It's a bit of a complex project, but I think its can be done cleanly and be worth it in the long run.

Re: Another Mini-Split discussion

Reply #3 – March 21, 2023, 03:39:05 pm

Random thoughts... is it possible that an RV park would have 50 amps from a single side, where 220 volts would not be available? Is it likely?

Re: Another Mini-Split discussion

Reply #4 – March 21, 2023, 04:03:35 pm

Quote from: oldmattb – March 21, 2023, 03:39:05 pm

Random thoughts... is it possible that an RV park would have 50 amps from a single side, where 220 volts would not be available? Is it likely?

Any think is possible, but not likely.

Re: Another Mini-Split discussion

Reply #5 – March 21, 2023, 04:15:28 pm

Quote from: oldmattb – March 21, 2023, 03:39:05 pm

Random thoughts... is it possible that an RV park would have 50 amps from a single side, where 220 volts would not be available? Is it likely?

You mean a 50amp single pole? Not likely as that is not standard anywhere. 50amp double pole can be split if you want single pole going to a camper or whatever else. 30 amp can be split in order to feed two sides of a breaker panel. They also make an adapter that will take one 30 amp input that goes to one pole and a 20/15 amp input that goes to the other. Most places have 30 amp with a 20 amp circuit built in, so this would work for 50 amp rigs that could use a little more power. Only concern is if that box has wire that is over-gauged to allow use of both 20 and 30 amp plugs. I would hope that they have a breaker on the other end of their circuit.

Re: Another Mini-Split discussion

Reply #6 – March 21, 2023, 04:24:54 pm

Zach another option I have considered is two 110v units. I probably have room for that in the nose of my GV, not sure you will in your coach though. For obvious reasons I'd rather only have one unit but it would simplify the electrical side of things

Re: Another Mini-Split discussion

Reply #7 – March 21, 2023, 04:43:01 pm

Could you find an older CG with both hots on the same leg? I guess, particularly if the CG was originally wired for 30 amp (one hot) and "Bubba" installed 50 amp outlets.

It would definitely be WRONG! And, even in a coach with no 240 VAC appliances, care would be needs to not overload the neutral since the neutral would now be carrying the sum of amps on L1 and L2 instead of the difference.

Re: Another Mini-Split discussion

Reply #8 – March 21, 2023, 04:44:06 pm

Here was one vendor at Quartzsite's solution on where to put the unit!

Re: Another Mini-Split discussion

Reply #9 – March 21, 2023, 05:49:02 pm

Quote from: Zach – March 21, 2023, 04:15:28 pm

. . They also make an adapter that will take one 30 amp input that goes to one pole and a 20/15 amp input that goes to the other. Most places have 30 amp with a 20 amp circuit built in, so this would work for 50 amp rigs that could use a little more power. Only concern is if that box has wire that is over-gauged to allow use of both 20 and 30 amp plugs. I would hope that they have a breaker on the other end of their circuit.

If the 20 amp plug is GFI protected, which all should be. That will not work, the Gfi breaker or plug will keep tripping.

Re: Another Mini-Split discussion

Reply #10 – March 21, 2023, 06:00:10 pm

Quote from: turbojack – March 21, 2023, 05:49:02 pm

If the 20 amp plug is GFI protected, which all should be. That will not work, the Gfi breaker or plug will keep tripping.

I'm not sure what you are saying.

This is what I'm talking about. Amazon.com: Camco - 21050 Heavy Duty PowerGrip Maximizer 45 AMP Adapter -... It allows two strings (30a and 15a) to combine into a 50a plug. Together, it creates 45 amps I suppose rather than 30a on one and 15a on the other.

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Another Mini-Split discussion

Reply #11 – March 21, 2023, 06:28:51 pm

The 12k inverter mini split I installed in my 36ft U270 does a good job of keeping the front half cool/warm and the dehumidifier also helps in the summer We usually leave an 8" fan on the table to blow air towards the back. have left it running 24/7 since it was installed last summer, helps keep the electronics warm and dry, my electric bill did not seem to go up to much. would defiantly do it again.

Re: Another Mini-Split discussion

Reply #12 – March 21, 2023, 06:35:14 pm

Quote from: Elliott – March 21, 2023, 02:28:02 pm

I've been going through the same decision process for my GV. I thought about the roof-mounted units but ultimately decided I don't want to expand the hole sizes in the roof.

An adapter and cover could be made to place a ceiling cassette on the roof without enlarging the ceiling/roof hole.

Re: Another Mini-Split discussion

Reply #13 – March 21, 2023, 06:39:09 pm

Quote from: Tommy D – March 21, 2023, 04:44:06 pm

Here was one vendor at Quartzsite's solution on where to put the unit!

Ugh... I'm not a fan. They took a great looking rig and turned it into an absolute eyesore.

Re: Another Mini-Split discussion

Reply #14 – March 21, 2023, 07:14:40 pm

Ah thank I'll jus hang mine on the rear view mirrah!!! Right nex to my ded deer!!! Um Huh.

Re: Another Mini-Split discussion

Reply #15 – March 21, 2023, 08:28:54 pm

Of course a campground could have a 50-amp pedestal female plug with both hots wired from same underground leg. Not supposed to, but it works, so they may do it, maybe during expansion, etc. Only downside if you don't need 240 volts is overloading neutral and maybe some voltage drop.

Easy to check. We had a permanently wired small neon light that was wired to both hot legs. When it lit up, which was most of the time, we have 240v.

Re: Another Mini-Split discussion

Reply #16 – March 22, 2023, 07:19:46 am

A point to consider regarding mini split installations in a motorhome is noise level from condenser unit. I wouldn't want one that exhausted into the patio area under awning, and doubt neighbors would appreciate one aimed at them in a typical urban rv park. These things make some serious fan noise when running full tilt and throw out tons of heat. Nose mount seems best.

Re: Another Mini-Split discussion

Reply #17 – March 22, 2023, 10:17:48 am

Quote from: Chuck Pearson – March 22, 2023, 07:19:46 am

A point to consider regarding mini split installations in a motorhome is noise level from condenser unit. I wouldn't want one that exhausted into the patio area under awning, and doubt neighbors would appreciate one aimed at them in a typical urban rv park. These things make some serious fan noise when running full tilt and throw out tons of heat. Nose mount seems best.

It's so quiet that I hang a streamer near it to tell that it's working .. they are very quiet.
My 12000 unit is more than enough to cool our tiny 36 ft GV
I also use a small fan to blow the air into the bedroom when needed .

Re: Another Mini-Split discussion

Reply #18 – March 22, 2023, 10:35:51 am

This post over at Newell Gurus (of the Tom McCloud HWH kit fame) is very interesting. The inside units the OP used are new (at least to me) and might work for you especially the one he mounted on the cabinet.
Also pay particular attention to the Growatt inverters he used. They split the incoming 120Vac into 2 separate phases, thus allowing you to use a 240Vac mini split on 120Vac. So you could use a typical 30amp 120Vac campground pedestal to power a 240Vac mini split.
You might need to register but that's relatively painless and quick
New LG mini split heat pump on the way

Re: Another Mini-Split discussion

Reply #19 – March 22, 2023, 10:53:32 am

I ordered a 220V model for our house but many one ton (12,000 btu) found on ebay are 110V. mini split air conditioner for sale | eBay

I was thinking that the area below the window opposite the sofa and behind the co-pilot's chair would be a good location on our coach. Taking the AC compressor off and replacing it with a second alternator like Mike did would allow an inverter to run it while driving. Also, it could power electric fans to get rid of the hydraulic system as Mike has done.

Tommy/Elliot, good photo, it reminds me of my favorite book, Grapes of Wrath.

Pierce

Re: Another Mini-Split discussion

Reply #20 – March 22, 2023, 12:09:04 pm

I have used mini-splits in our computer room to keep it cool. In the last 20 years I have gone through about 3 units. I have given up on mini spits and gone with a regular AC unit in there now.

When purchasing one you need to check and make sure the unit will turn back on when power is lost. The first unit we got was any little power glitch the unit would shut down and you would have to manually turn it back on.

Re: Another Mini-Split discussion

Reply #21 – March 23, 2023, 12:47:40 pm

Diving further into this rabbit hole of mini-splits and power usage. Now trying to figure out how to use something like a Nest/Ecobee thermostat to run them in conjunction with Alexa/Google AND with the Aquahot. I'm not entirely sure how the AquaHot talks to the Comfort Control, so I'll have to figure that out, but being able to use Alexa/Google to turn on the mini-split/AquaHot and control the temperature would be awesome.

As far as power is concerned, I was considering a change in my power wall to go with two inverters or one split-phase inverter, and am now thinking that'll be the best path along with a couple more batteries. One potential roadblock is figuring out how to get split phase from the 10kw generator. I don't use the generator much but it would be nice to not have a power issue if I turn it on and have the mini-split running.

Re: Another Mini-Split discussion

Reply #22 – March 23, 2023, 01:12:16 pm

The Aqua Hot communicates with the Dometic thermostat via the air conditioner circuit board. Two individual wires (often blue and blue with white stripe). A relay on the air conditioner circuit board closes to turn on the Aqua Hot. Temperature control is by the thermostat.
Jim

Re: Another Mini-Split discussion

Reply #23 – March 23, 2023, 01:15:30 pm

Zach, The AH interior thermostat ground signal for your 99 coach comes from roof A/C circuit board. No A/C, no circuit board, no AH.

The solution is a thermostat for each zone up in coach independent of new A/C. One side of thermostat is connected to ground and the other side to the zone connections on top of the AH.

Re: Another Mini-Split discussion

Reply #24 – March 23, 2023, 02:44:32 pm

Pioneer makes a 120v , 12000 unit that would save a lot of wasted electron changes.
Non of these will run very long off if the batteries.

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