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diy solar

DC powered Mini Split Air Conditioning system

Maybe missing something here but you say that you have a grid connection and you have a ton of spare PV panels ... would it not just be easier to grid-tie your panels and run the A/C from the grid? Your array will claw back any excess grid draw over time. Grid tie inverters are not that expensive, you'll probably find one on eBay for $100.
 
Going to hijack this thread here. I'm looking into 24v DC split ACs for my van, also since I don't even have one in the cab. I have a 280ah 24v lifepo4 pack and 1360w of solar. Don't wanna run it through the inverter if possible.

There are loads of those DC Air conditioners on Alibaba, mostly for construction and farming use.

I just reached out to this one to get some proper data sheets


I like having ducted outlets so I can distribute it around the van. The outdoor unit can be mounted under the van.

Any thoughts on those?
 
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We have allot of those little Toshiba 6000 BTU A/C's that you can get from Home Depot ... and we have allot of Trojan-31 AGM Batteries on communication gear that we are switching out for LiFePO4 ... so to try to help out the mechanics and tool guys working out of cconex offices -- we get these cheap SCC's -- hook up (4) 100aH 6V batteries - run it to a 1000W inverter ... and this literally powers the A/C all day long for the guys ... We also have a BMS that cuts off the drain when it gets too low and in the morning fires up the A/C automatically when the V/A is high enough ... The A/C draws a max of about 520 watts on startup and settles down nicely once it gets going .... https://www.homedepot.com/p/Toshiba...nditioner-with-Remote-RAC-WK0611CRU/303408315
 
We have allot of those little Toshiba 6000 BTU A/C's that you can get from Home Depot // working out of cconex offices

I've seen that exact combo at burning man. except they use gens not solar.

I wish I could cool and de-hu with 6000btu. I have two 13,500 units.
 
I've seen that exact combo at burning man. except they use gens not solar.

I wish I could cool and de-hu with 6000btu. I have two 13,500 units.

so it sounds like you have an RV ... for some of the RV's that have two doors .. we take the AC .. put it in the door ... we open the door -- cut R-5(?) foamboard insulation to fit the door tightly ... then cut the bottom of it off so the A/C will fit ... then run the A/C via the sun all day ... at night when they pack up - they just slide the A/C and the foamboard in the door - close it - lock it .. and its done ... I honestly believe that little 6000 puts out more cold then the 13500 they have
 
I have a 12,000 btu mini split mounted nicely on the back of my bus conversion (40' MCI 102a3). It is 120ac and I run it off from a 400ah 12v battery bank. It is, of course, inverter technology and soft start. Works great.
 
so it sounds like you have an RV ... for some of the RV's that have two doors .. we take the AC .. put it in the door
Very interesting point.

I currently use one of the all-in-one A/C units in my caravan but it is sooooooooo crap. Because it pulls in air from outside, you only ever get a couple of degrees of cooling in operation. Might have to consider cutting a new hole in my caravan...
 
Very interesting point.

I currently use one of the all-in-one A/C units in my caravan but it is sooooooooo crap. Because it pulls in air from outside, you only ever get a couple of degrees of cooling in operation. Might have to consider cutting a new hole in my caravan...

I have to drive about 140 km out to the site tomorrow and if the trailer is still there i will send pics ... not the prettiest design BUT we did not have to cut a hole in anything (which is disappointing because we are getting pretty good at not measuring correctly and then cutting anyway)...
 
so it sounds like you have an RV / foamboard // that little 6000 puts out more cold then the 13500 they have

yeah, dual rooftops on a shared duct system. a window unit would be a lot more efficient with less BTU's. i have windows that slide open big enough to fit a small window a/c if I built framing to help support it.

in sticks and bricks I always put foam board around window units. the little accordion things they come with are jokes.

I'm hoping my rooftop units last until someone starts selling a rooftop inverter heatpump in the US. I just cleaned the coils. the shrouds are brittle so I'm covering them in aluminum tape (ugly but whatever)
 
I got a bit more information about the DC air conditioning. Any thoughts on this? They claim to have 2 styles for the outside unit, both with the same price and the same specs. I'd go for the more square-ish one (but I do believe that it's thicker than the 6.1inch in the picture).

Screenshot from 2020-06-04 12-19-55.png

Any thoughts on this? The price including shipping seems about the same as a cheap domestic AC bought locally but it would be 24V DC powered with no need to run my inverter. Sounds like a much better deal to me

There seem to be a few more, similar-looking ones, on Alibaba and Aliexpress.
 

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  • The Quotation about Parking air conditioner WAC1003.pdf
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only in AU, I had found that while looking.

in any case I like to see something out for a while before I adopt.

I'm sure dometic is charging a premium for a white label unit we could probably already order like lifepo4 cells.
 
Hello,

I picked up a used (barely used) generic brand Mini Split air conditioning system for cheap (1 ton cooling), that takes DC input.

The label on Compressor portion of the Air Conditioning Unit says:
Rated Volatge: DC 48V
Cooling Capacity 12000 (2000-13500) BTU
Rated Input Power (Cooling) 850 (100-13000) W

I have some Kyocera KC158G PV Modules. The specs on these are:

Max Power: 158W
Max Power Voltage: 23.2 Volts
Max Power Current: 6.82 Amps
Open Circuit Voltage: 28.9 Volts
Short-Circuit Current: 7.58 Amps

I’m interesting in powering this unit with the PV modules directly.

It seems like I would have a 2S3P arrangement: 2 in series (23.2VX2=46.4V), and 3 in parallel (850W input power required / (158 W X 2 ) = 2.7)

I realize I'm falling short of the input voltage by 1.6 (48-46.4 ), but I'm guessing that might be negligible as it is 97% (46.4/48) of the input voltage.

Would love to hear your thoughts about this project. I have never hooked up anything solar before, but have a background in EE /physics in college classes with lab work, so understand enough to possibly know if I am going to kill myself, and of coarse the home repair projects wiring things up.

Would love to have your opinions here on this project.

Thanks in advance.
Hey, this looks super interesting. Did you ever set it up? I'd love to try something like that.
 
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