replacement air conditioner

[Chewydog]

I want to replace my rooftop air with a mini split cassette like the one in the attached video.
https://www.youtube.com/watch?v=aDXKuZaMXoY

My plan is to run it on solar and batteries.
Problem is, all the ceiling cassettes that i can find are 220v
I think I could make that work but it would be way easier to find a 110 unit. All the 110 units are wall mound and I have a very small travel trailer with nowhere to mount a wall mount type.
Would it be recommended to run a 220 inverter for ac only? Are there inverter chargers that run split phase 220 and I could pull 110 from that as well?
Any suggestions?

[Gdetrailer]

Dirtyrhoades77 wrote:
I'd also rather have a ceiling cassette rather than a wall unit. Too bad it seems to be a niche product.

Nothing like digging up "bones" on a old thread back from Sept 2020..

[Dirtyrhoades77]

I'd also rather have a ceiling cassette rather than a wall unit. Too bad it seems to be a niche product.

[n0arp]

pianotuna wrote:
Chewydog,


There are 48 volt dc air conditioners. Some are mini splits.

There are two importers (as of a year or so ago) of these units in the US - I really, really wanted to go this route as I have a 48V system. For the OP, unfortunately neither import cassette units but one could probably be imported via Alibaba/Ebay or a similar source. But that brings me to my second point - because I wanted these units but couldn't find reviews on them, I went on Instagram to do hashtag searches and PM'd users who had installed them. The overwhelming majority of responses I received were to "stay away" because they seemingly all had issues. Just relaying the word of warning.

I went with a LG 240V multi-split, so that I can get parts if needed and because they had the most efficient condenser unit in the class. With the same 30K of advertised capacity as my rig came with, these cool and heat much better, and use a third of the energy in day over day comparisons. It's still possible to see them pull a combined 2.5kW at times (heating), but they do so for much shorter periods and typical draw is closer to 700W per 15K indoor unit, when running on high cool or less than half that once the room is close to the desired temp.

[TurnThePage]

It's nice to see these options out there. Definitely expands my future RV choices.

[pianotuna]

Chewydog,


There are 48 volt dc air conditioners. Some are mini splits.

[n0arp]

pianotuna wrote:
Hi,

I vote for the 240 volt inverter. Mini-Splits are the bomb!

Here is a 115 volt Mini Split.

https://www.homedepot.com/p/Pioneer-Low-Ambient-12-000-BTU-1-Ton-20-SEER-Ductless-Mini-Split-Wall-Mo...

time2roll wrote:
120v:

https://www.amazon.com/WYS012-17-Air-Conditioner-Inverter-Ductless/dp/B01DVW6G06

Both of those are wall units - the OP is specifically requesting a cassette unit, which only comes in 240V as far as I've seen.

[time2roll]

120v:

https://www.amazon.com/WYS012-17-Air-Conditioner-Inverter-Ductless/dp/B01DVW6G06

[n0arp]

Chewydog wrote:
The biggest problem I see using a 12v to 220 inverter would be when I'm using a generator or plugged into 120v. The converter would have to charge the batteries at a rate the inverter is pulling from the battery. Doesn’t sound like a good idea.
Is the best thing to get an inverter charger with auto transfer with an attached autotransformer.

Is there an all in one unit that can give me split phase 240 and 120, auto transfer and charge? I know I’m asking a lot for a single unit to do, but would make my life simpler.

The best solution, at least in Victron world, would be a single MultiPlus or Quattro and an Autotransformer - assuming you have a 30A rig. If you have a 50A rig, you have the option of a 240V MultiPlus or Quattro with an Autotransformer to handle your 120V loads, or a pair of 120V MultiPlus/Quattros and an Autotransformer would only be necessary if you want to be able to run your air conditioner on any input source without inverting and charge using the full capacity of the inverter/chargers.

Magnum makes a MSH3012RV that you'll probably run across, but I'm pretty sure both legs are in phase with one another, so it won't actually produce the 240V you are looking for. And there would be a host of other issues you'd have to work through with it.

[Chewydog]

The biggest problem I see using a 12v to 220 inverter would be when I'm using a generator or plugged into 120v. The converter would have to charge the batteries at a rate the inverter is pulling from the battery. Doesn’t sound like a good idea.
Is the best thing to get an inverter charger with auto transfer with an attached autotransformer.

Is there an all in one unit that can give me split phase 240 and 120, auto transfer and charge? I know I’m asking a lot for a single unit to do, but would make my life simpler.

[n0arp]

time2roll wrote:
I would go with a 240 volt sine wave inverter dedicated to the mini.
I like separate components but get a combo unit for the 120v if you must.

Yes Victron makes inverters that can be connected to make 240/120 split phase service. I think in the end this would make it more complex.

Yes, Victron makes inverters that can be stacked to make 240V split phase. They still recommend an Autotransformer on the output side to load balance 120V loads across both inverters (though most RV installs seem to skip this - I don't recommend doing so) and if they are stacked, then if you plug into single phase service the second inverter will reject the input because it isn't out of phase and thus, only one inverter will be used for charging. If you run ESS, then both inverters will reject the input. To work around this they make - guess what - an Autotransformer.

In the end, the best solution for the user here (assuming the rig is 30A) is probably a single Victron inverter and an autotransformer in the role I initially explained. Everything else is over-complicating things for no benefit.

The Autotransformer consists of a couple windings and a breaker. Not much to go wrong with one and the MTBF is >100 years.

[pianotuna]

Hi,

I vote for the 240 volt inverter. Mini-Splits are the bomb!

Here is a 115 volt Mini Split.

https://www.homedepot.com/p/Pioneer-Low-Ambient-12-000-BTU-1-Ton-20-SEER-Ductless-Mini-Split-Wall-Mo...

[time2roll]

I would go with a 240 volt sine wave inverter dedicated to the mini.
I like separate components but get a combo unit for the 120v if you must.

Yes Victron makes inverters that can be connected to make 240/120 split phase service. I think in the end this would make it more complex.

[mr_andyj]

as jformer said, 240 will make life more difficult when u can plug in.

You can get a 240 inverter of course too.

Mini-splits are really nice. I sure would love to have one. Running this off solar is huge, you know? Do you have enough roof space for the amount of panels that you will need? You also will need a big battery bank depending how long you want to run it, just in the middle of a sunny day, or overnight?

A small gas generator would run this easily, and gas will run it all night. Compared to solar, the small generator (inverter generator) would be more cost effective. Im sure you have looked into this though.

My 2200 inverter gen will run my inefficient 9200BTU roof AC for about 11 hours overnight on I think about 1 gallon (external tanks available). The AC compressor only runs maybe 10-15 mins total each hour.


from a site:
The Ryobi RYi2200 inverter generator is a gasoline (can use E10) powered generator which has a fuel tank capacity of 1 gallon. It provides only run time about 4 or up to 5 hours on one tank of gas at 50% load capacity and around 2.5 hours at full load.

[n0arp]

Chewydog wrote:
I’m a little confused on what a victron auto transformer does. Does it only turn 120 into split phase 240 or does it also turn 12v into 240. Would I need a inverter to feed the auto transformer? If so it sounds like a lot of efficiency loss.

Thank you

First, the Autotransformer only deals with AC current. So yes, you will need an inverter - ideally for your whole rig.

Second, autotransformers are incredibly efficient - in the high 90s, up to 99%. You will find the overall system, with a quality inverter, far more efficient than the rooftop unit you are looking to replace.

Finally, it's by far the cleanest solution as it will allow you to run a 240V AC unit both disconnected, and when plugged in to single phase 120V electrical sources, directly from the source rather than always using your inverter.