Mini split refrigerant recommendation

[bluedog225]

I’m going to install my first mini split. This will be in my shipping container to keep my solar equipment and batteries cool. I’ll be installing three more units in my workshop/cabin in the spring of 2026.

I’ll be buying the tools in the vacuum pump and probably a nitrogen set up to do this all correctly. I may cheap out on the first unit for the shipping container and get something small and cheap off Amazon so if I mess it up, I won’t be out too much. The later units will probably be higher quality.

I’ve been reading up a little bit on the whole refrigerant deal. Given that I’m starting from scratch today, should I go ahead and buy R-32 units?

what’s the smart move here?

thanks

 

[PCustoms]

Will these be running off the solar?

Any reason you're not looking at pre-charged units/lines?

 

[mepstein]

They all come pre charged. Mr Cool just don't need the lines evacuated.

 

[theoldwizard1]

A good vacuum pump and a good gauge set is all a DIYer really needs. If you want to splurge, get a micron gauge. If it holds a good vacuum for several hours your good.

 

[bluedog225]

The precharged line units are substantially more expensive.

 

[Firebrick43]

The precharged line units are substantially more expensive.

Yes but the unit itself is precharged. You just have to pull a vacuum to purge air and check for leaks. When you open the valve to the unit it is fully charged as long as your lineset length is reasonable. Usually 25’ and under doesn’t need any additional refrigerant

Also why cool your solar setup?

A spaced roof over the container with some ventilation between us more than sufficient and you don’t have to buy a lot more batteries and panels just to run the mini split

 

[bluedog225]

Yes. These will run off solar and batteries.

and yes, you and I agree on how the charge works in the units and sometime in the pre charged line sets.

The batteries and electronics do better in human comfortable environment (temp and humidity). It gets 110 eff in central Texas. Shortening the useful life of the batteries.

I’ve got plenty of land, panels, and batteries for power.

Also, as mentioned in the first post, I’ll be installing several more splits (4 total).

My real question is which refrigerant is the smart choice at this point in time.

 

[American Locomotive]

It doesn't matter. Just buy whatever unit fits your needs. R410a will still be available for a very long time. The choice will be made for you soon enough though, as most manufacturers are transitioning over to R32 or r454b and R410a stock will become depleted.

 

[462867aa]

I bought 2 units last year. Only a few were 410a units. The vast majority were r32. That's what I got. No extra refrigerant was needed, but r32 is not a problem to find. I would pick r32 again if needed.

 

[MushCreek]

I've noticed that more and more of the new minis are moving away from 410A. I'm going to be installing one in my shop soon, but I'm going to get 410A because i already have three of them, and just bought a jug of it. Otherwise, I'd try to figure out where the newer units are going to go.

 

[fitter30]

R 32 is a replacing for 410a but isn't a replacement. There not compatible. Buy equipment that use R32.

 

[pcmeiners]

This will be in my shipping container to keep my solar equipment and batteries cool

So if it is only for cooling why not get an easily replaceable air conditioner ?, cut a hole in the container and mount it. If it ever fails, run down to HD and get a replacement in a couple hours ... that will not happen with a mini split. Not against min splits, I have (5), just for the container an air conditioner would be more practical, so would foam 4x8 insulation panels

 

[Dagny]

Pretty smart

 

[bluedog225]

I agree, a window air con would be easier. But it introduces greater opportunity for theft.

Mylar on the outside of the foam. With air gap.

 

[PCustoms]

Yes. These will run off solar and batteries.

Have you done the math on this?

I've seen a few projects go into a tailspin when the required HVAC creates more heat/power consumption so then the power gets up sized then more HVAC is needed etc.

 

[bluedog225]

Have you done the math on this?

I've seen a few projects go into a tailspin when the required HVAC creates more heat/power consumption so then the power gets up sized then more HVAC is needed etc.

See below for today’s data. This is pretty representative of what the summer will look like. The consumption will be higher if it gets up to 110.

The current Midea dual hose portable air conditioner and other equipment draw about 350 W on average though I can get up to 750 on occasion. It’s an inverter style so it ramps up and down as needed without much concern about locked rotor amps. It’s vented through a hole in the floor.

As you can see, the batteries fill up pretty quickly. And production is throttled back by the charge controllers to cover the air conditioner, the Starlink, and the inverter self consumption.

It’s working fine, but I would like some redundancy. And these portable units are not known for their reliability. Once I install a mini split (or window unit), I’ll use the Midea as a hot back up.