Powering a Mint Split unit in an RV by solar and lithium batteries

[Archetype-IS]

It doesn't seem that unit can throttle the compressor load like the one in the other video .... but seems he has enough solar that it doesn't matter.
Not sure I like the way he routed the air from the condensor unit.

The ForestAir unit is not a high SEER rated unit. It only has 8.8 SEER. No better than the windows air conditioner. The mini-split is just more efficient on running. Plus his Everlander has no windows like he first said in the video. Less heat from the sun. Good insulation.

 

[Bob B]

The ForestAir unit is not a high SEER rated unit. It only has 8.8 SEER. No better than the windows air conditioner. The mini-split is just more efficient on running. Plus his Everlander has no windows like he first said in the video. Less heat from the sun. Good insulation.

I'd rather have the windows .... with a high seer unit.

 

[Archetype-IS]

I'd rather have the windows .... with a high seer unit.

Similar questions and answers from another post about mini-splits in an RV. Always a trade off with designs and engineering.

Powering a Mint Split unit in an RV by solar and lithium batteries

They runed That's cool. Long ago, a YouTuber Technomadia (I can't find that video now, it was like 4 to 5 years ago) did their bus with Victron inverter, Lithium batteries, generator,DC to DC charger because their bus has a huge alternator to help charging it. Forgot how much was their solar...

diysolarforum.com

 

[grizzzman]

Technomadia has a blog about there first LFP and there upgrade.

 

[grizzzman]

Technomadia Blog about there first LFP bank and there upgrade.

 

[Freep]

I really. liked that Gone Boondocking video. With my Lance truck camper, if I removed the roof A/C and installed a mini split it would free up roof space for more solar and only use about 1/2 the power of my existing A/C unit. That might make it possible to boondock almost anywhere. The current roof A/C is not only taking up roof real estate, but also shading a significant area.

Very interesting that he is improving the efficiency even more by controlling the load by leaving it run all the time.

I was thinking the exact same thing for my Lance. Usually we just move to a cooler place, but we've been stuck in hot areas a couple of times this trip and I wish I had some AC so I could work.

Lance 2014 992
2014 Ram 3500 DRW turbo diesel.

 

[Ledsun]

I wish that someone who has done this put out all the specs because it is so confusing. It's too much money to gamble on.
I saw some panels that were 195 watts and I believe I could get four on my roof and they are affordable. But the lithium batteries
might be the expensive part. But the site owner found some used medical batteries on the cheap.
The owner of this site did a small window ac but I wish he would do a split unit for a mobile install.
There is a real market for this if it can be done.
I need a cookbook method.
I can only imagine how nice it would be to be on the SC coast looking out the
windows with cold ac and no mosquitos with stealth style sound

 

[Dzl]

Mini splits are getting pretty popular with skoolie builders and dwellers. If you search around on Skoolie.net (see here) there are a handful of posts on it, and more than a handful of people who have installed mini-splits in their buses, a few of which power them completely off of solar/batteries. The discussion over there is a bit less tech savvy, but there are some smart people, and a good amount of people with real world experience.

 

[Michael B Caro]

I have been running a mini-split in my bus for 3 years and instling a second one tomorrow.

 

[Dzl]

I have been running a mini-split in my bus for 3 years and instling a second one tomorrow.

Nice what size and SEER rating? Is your solar system able to keep up, or do you use a generator or other source to compensate?

 

[Michael B Caro]

Nice what size and SEER rating? Is your solar system able to keep up, or do you use a generator or other source to compensate?

12K btu, inverter technology, heat pump, Air Con mini-split. I think this one is a 16 seer. The one I am putting in now is a the same but is a 20 seer made by Daizuki. I was running with 4 6v trojan L16's but I am now just in the process of switching over to a LifePo4 battery 24v battery bank. The L16's would do ok and but I am not sure if my 6 solar panels would have/will keep up or not because I never tried keeping the batteries topped up with just solar. I can also charge when hooked to shore power, have a 4K generator that can charge the house batteries, and have the bus cabled to charge the batteries off the alternator via the start batteries when running down the road.

 

[eXodus]

Alternative there are Inverter Window A/C Units starting to get into the Market.

8,000 BTU U-shaped Air Conditioner White MAW08V1QWT | Midea - Make yourself at home

Introducing the first ever U-shaped Inverter Window Air Conditioner that allows you to open or close your window while the unit is installed.

www.midea.com

Which depending on the Setup (Van) might be easier to install.
I'm cooling a heavy insulated Chevy Express Hightop Van with a regular 6000 BTU Window Unit.

Looking into how much Solar I would need to run it.
Have you guys ever plugged your Units into a power-meter- kill a watt and measured how much it needs over a day?

 

[Bob B]

HMMM ...That's an interesting unit .... but it looks like it may still not be as efficient as the high seer split units.

The energy sticker on that shows a 15.0 "combined energy effeciency ratio." Does anybody know if that is the same as a seer rating?

It would sure be nice if they would stick to some standard terminology when rating these things.

 

[eXodus]

It's only one of many window units with inverter. LG makes one, as well as others.

I agree they are probably not as efficient as a split unit. But people in vans don't have the space most of the time for a external condenser unit.

So the choice is between a 9-11 seer regular window unit or a 15 seer inverter drive unit. You just can not add a 23 seer unit to a van. I got one for my garage. The outside unit is huge. Not heavy but high volume

 

[Michael B Caro]

That unit is interesting, but the mini-split is a lot quieter than 42 decibels, and has the advantage of being available in heat pump version.

 

[RCinFLA]

Mini-Splits are usually inverter-compressor based. Inverter (3 phase compressor motor run by electronic inverter) units have low startup current only slightly more then their run current.

Inverter air conds are actually less efficient when running at full capacity. If you buy an undersized unit that runs full power most of time you will actually use more energy then an equivalent BTU sized regular split unit running nearly all the time. The difference is the lost in inverter conversion efficiency. A window unit just sucks in transfer losses from shoving evaporator, condenser, and compressor in same box at close quarters.

 

[eXodus]

That unit is interesting, but the mini-split is a lot quieter than 42 decibels, and has the advantage of being available in heat pump version.

the manufacturer really just started this year to build Inverter A/C - it's probably only a matter of time until they come out with a "Inverter Heaterpump Window Unit" I'm not big fan of Window Shakers either. But currently it's the ONLY option for a small Van build.
But I thought a share the most modern version of the old idea.

On a bigger RV I would absolutely go for the Mini Split.

 

[cwstnsko]

I’m not sure how you’d go about fitting that u-shaped unit into a vehicle. The inside and outside parts cannot be separated. It’s designed to be placed in a large open window and then have the window closed into the channel in the center. I think the smallest capacity LG inverter unit would be much easier to fit

 

[eXodus]

LG 9,500 BTU DUAL Inverter Smart Wi-Fi Enabled Window Air Conditioner (LW1019IVSM) | LG USA

Shop LG LW1019IVSM on the official LG.com website for the most up to date information. Buy online for delivery or in-store pick-up.

www.lg.com

The LG is a great choice.

The Midea u-shaped works perfectly fine when you got a big opening cut into your wall anyhow. Just slide a flat wide board/pice of wood/metal in the U (and insulation) - let it stick out on both sides to attach to the original wall. - much more secure then a regular window unit which only holds with a tiny metal bracket on the top.

 

[DW SD]

Any reason not to do roof mounted units? They can be ducted.

I have some real world data that might help predict loads and system needs. I have a dometic duo therm roof AC and heat pump. likely 15k BTU, 90% certain. If not that, 12.5k.
900W (3) of 60 cell panels mounted flat. Magnum PT100 MPPT charge controller. Magnum 2800W pure sine inverter / charger.
280Ah x 13.2V home grown battery.
Bus is fairly well insulated for a mobile vehicle. Good 3" of spray foam from Bluebird Wanderlodge RV factory.
85F ambient. Thermostat set to 73F. AC unit would get get down to temp quickly and then cycle maybe every five or ten minutes for a few minutes. Duty cycle approximately 30% to 50% for AC unit.
I was drawing NET between -120 and -160 DC amps. So with duty cycle, -50Ah to 80Ah per hour of AC use for -13F vs. ambient.
Each 300W panel puts out about 20 amps @ 13.2V DC in full mid-day sun.
Total DC load would then be 180A to 220A from the AC unit.
My Magnum inverter had no issue with compressor startup. My AC unit is stock, but I have on hand a heavy duty startup capacity to install.

So with twice as many panels, you'd probably still draw -60 and -100 amps @ 12V, but only when the unit is cycling, assuming similar capacity unit in terms of BTUs. You could pro-rate against 15k BTUs to determine the approximate draw.
If you are in HIGH ambients, your duty cycle on the AC unit would likely approach 100%. I was in 100F with hookup and AC runs pretty much non stop.

Hope this helps. #s might get you in the ballpark.

Doug