Powering a mini split

[HookEm]

Gearing up to try and run a 9k btu, mini-split from pioneer. Tried and failed without doing my research off a 200AH amperetime and 150w solar panel. New setup comes early-September in SoCal high desert (to cool 80sq ft bedroom):

• Solar array: 750-1000w of panel depending on what can be fit.
• Storage: 618AH SOK lithium running in parallel.
• Power: 2200w pure sine wave giandel inverter
• Mppt charge controller (any recommendations for better and priced under $500?): 40a rich solar mppt charge controller

I’m hoping the small size of room, ample sun and cool nights allow this setup to run 24/7. If anyone has a good recommendation on charge controller, please send (using 10 gauge wire into the charge controller, so needs to accommodate). Will let all know if this works.

Ummh... I don't expect that you'll run it 24/7.

If you start with average consumption from the Mini-Splt, you can then get an idea of how much you'll need:
1) At night, running solely from batteries: Add Mini-Split to other nightime consumption
2) During the day, pulling from Solar: Add Mini-Split to other daytime consumption, and add power to recharge batteries.

My guess is that 618AH may be enough, or close to enough... but 750-1000w from Solar will not be!... You'll need to double it!
The 2200w Inverter may or may nor work depending on your overall AC consumption, but my guess is that it may fall short!
(E.g., You may need to take the factory inverter and add at least another 1000w to run the Mini-Split).

Anyway, you should be able to get a decent idea of what you need (Solar, Batteries, Inverter) based on your consumption (Nightime & Daytime).
(It should not be trial-and-error or lucky crap-shoot).

So instead of "wishing you luck", I'd urge to "do the numbers" (comsumption numbers, that is).

 

[Jcashin]

Ummh... I don't expect that you'll run it 24/7.

If you start with average consumption from the Mini-Splt, you can then get an idea of how much you'll need:
1) At night, running solely from batteries: Add Mini-Split to other nightime consumption
2) During the day, pulling from Solar: Add Mini-Split to other daytime consumption, and add power to recharge batteries.

My guess is that 618AH may be enough, or close to enough... but 750-1000w from Solar will not be!... You'll need to double it!
The 2200w Inverter may or may nor work depending on your overall AC consumption, but my guess is that it may fall short!
(E.g., You may need to take the factory inverter and add at least another 1000w to run the Mini-Split).

Anyway, you should be able to get a decent idea of what you need (Solar, Batteries, Inverter) based on your consumption (Nightime & Daytime).
(It should not be trial-and-error or lucky crap-shoot).

So instead of "wishing you luck", I'd urge to "do the numbers" (comsumption numbers, that is).

Thank you for the rundown, Hookem. I need to clarify, when I say 24/7, I mean powering on and off to maintain ~78 in the bedroom. Thankfully the only load in addition to the AC will be a set of LED lights and occasionally a phone charge. This room is designed to sleep and look out at the views, nothing else. I’ll factor in the consideration for additional panels.

On the inverter front, it runs the AC no problem as of now, but does shut down when the 200ah battery gives out on us. Is it possible that the inverter is partially to blame as well? Or, assume inverter fine given its running the AC (has run it for 6 hours over night on a cooler night recently).

 

[niktak11]

I presume that it would be more like 7500W / 19 = 468W per hour... A bit more, but perhaps still not enough.
I say 19 with the assumption that during the 5 hours of ~full~ Solar the batteries are just charging, 24 - 5 = 19.

Does that seem reasonable?

I think you mean Wh/h (or just W). W/h would mean a rate of change of power.

 

[Daddy Tanuki]

Check out my graphs for Sunday through Today: https://vrm.victronenergy.com/installation/76892/share/d5bbdd04 ... 90F temps, full sun (today is supposed to get cloudy and stormy in the afternoon). My usual load is about 5kWh/day without the AC so the AC is adding another 10 or so.. and I'm able to produce enough to both run it and recover the batteries by 1pm (3.3kW solar, 27kWh battery).

Ok thats pretty friggin sweet. pisses me off I don't have any internet at the cabin other than when I am there with my phone. I think magnum offers a portal that you can track all of the inverter, and any attached items, BMS etc. and my solar controllers offer their own thing as well. If I had internet there I could track mine but not nearly as sweet as this. Victron tying it all together is sweet. That's how you corner a niche market like solar tinkerer's when you can offer it all in one package

 

[rcrracer]

Flexible line sets With a max length of 6,' this brings up a question. Mini split kits are sold with 25' or 15' line sets, implying that the refrigerant optimum quantity is for 20' line sets. What happens when only a 6' line set is used? Overcharged system?

Edit: At least one manufacturer has a minimum of 10' line sets.

 

[Daddy Tanuki]

I would be more worried about the fact that folks do not vacuum down the lines to remove moisture on these units. those copper tubes have 15-25' of moist air in them, and if you have not used a vacuum pump to remove the air and moisture from the line you will eventually have bigger issues than an extra 15-20 grams of refrigerant. your desiccant dryer will already be behind the power curve, and your expansion valves will be more apt to corrode shut... they are made out of aluminum after all.

 

[740GLE]

Most DIY Kits come with coils of tubing precharged so no evacuating is needed, making the connections open up the ports letting refrigerant flow.

you’d just need to coil up the extra tubing if you only need 6’ but have 20’.

If you want to cut and reterminate for a clean look that when you should higher a company to properly purge the system and recharge.

 

[Short_Shot]

Flexible line sets With a max length of 6,' this brings up a question. Mini split kits are sold with 25' or 15' line sets, implying that the refrigerant optimum quantity is for 20' line sets. What happens when only a 6' line set is used? Overcharged system?

If you're installing one of these you need the right equipment to charge it, which means you should have the specs and knowledge needed to ensure its properly charged.

Or you just have a coiled up line set in a cabinet somewhere for the "diy" kits you can't cut back.

 

[Short_Shot]

Most DIY Kits come with coils of tubing precharged so no evacuating is needed, making the connections open up the ports letting refrigerant flow.

you’d just need to coil up the extra tubing if you only need 6’ but have 20’.

If you want to cut and reterminate for a clean look that when you should higher a company to properly purge the system and recharge.

Beat me by seconds.

 

[Hedges]

If you want to cut and reterminate for a clean look that when you should higher [sic] a company to properly purge the system and recharge.

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Harbor Freight has expanded my DIY capabilities on the cheap.
But just coiling the excess is a better way to go.

If installing a new A/C system I would want it to do A/C, heat pump, divert to hot and cold storage tanks so compressor could run either when the sun shines or when utility rates are low. Then when the energy is needed, either air/water heat exchanger, or run the compressor but more efficient with better temperature at the other end.

 

[iamrich]

Most DIY Kits come with coils of tubing precharged so no evacuating is needed, making the connections open up the ports letting refrigerant flow.

you’d just need to coil up the extra tubing if you only need 6’ but have 20’.

If you want to cut and reterminate for a clean look that when you should higher a company to properly purge the system and recharge.

Keep in mind most split units (an ACs in general) need a minimum length lines (I think most are at least 10 feet), so you don't want to cut it any shorter than you need to.

They also sell a charge kit that eliminates the need to vacuum. You basically hook up the kit to the lines and pressurize them while letting the air bleed out the other end until fluid starts coming out. Probably not the greenest method, but the cans are $30 and come ready to use.

 

[Short_Shot]

Keep in mind most split units (an ACs in general) need a minimum length lines (I think most are at least 10 feet), so you don't want to cut it any shorter than you need to.

They also sell a charge kit that eliminates the need to vacuum. You basically hook up the kit to the lines and pressurize them will letting the air bleed out the other end until fluid starts coming out. Probably not the greenest method, but the cans are $30 and come ready to use.

I'll be honest. I've never seen this charge kit you refer to that would result in filling the lines front to back with a liquid. I'm also not claiming to be the expert here as I've only ever used a vacuum pump and gone home for the night while it runs.

Would this not require the rest of the system to be pulled to vacuum from the factory then?

 

[Hedges]

I hear the right way to evacuate a system is for extended time, to get all the water out.
I think having it warm helps too.
My experience with vacuum systems (instruments) is that heat and deep vacuum don't get all the water out. Dry gas flowing through is needed. Water is absorbed into and sticks to metal. But it may be good enough for refrigeration systems.

 

[iamrich]

I'll be honest. I've never seen this charge kit you refer to that would result in filling the lines front to back with a liquid. I'm also not claiming to be the expert here as I've only ever used a vacuum pump and gone home for the night while it runs.

Would this not require the rest of the system to be pulled to vacuum from the factory then?

Amazon.com: Pioneer KWIK-E-VAC Line Set Flushing Kit Installation Simplifier for Mini Split Air Conditioning Systems: Home & Kitchen

Buy Pioneer KWIK-E-VAC Line Set Flushing Kit Installation Simplifier for Mini Split Air Conditioning Systems: Air Conditioning Line Repair Tools - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

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[Short_Shot]

Amazon.com: Pioneer KWIK-E-VAC Line Set Flushing Kit Installation Simplifier for Mini Split Air Conditioning Systems: Home & Kitchen

Buy Pioneer KWIK-E-VAC Line Set Flushing Kit Installation Simplifier for Mini Split Air Conditioning Systems: Air Conditioning Line Repair Tools - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Neat.

Is this product then somehow flushed out of the line?

I'll have to read the manual later.

 

[iamrich]

The can contains Difluoroethane and is designed to displace everything else in the lines. R410 contains Difluoroethane so I assume the amount left in the lines will not effect the system once you release the factory installed R410 from the outside unit.

To clarify, this would not work for a completely uncharged setup. This is aimed at the mini split units that come pre-charged, but the line set is not.

 

[iamrich]

KWIK-E-VAC Line Set Flushing Kit Installation Simplifier for Mini Split Air Conditioning Systems

Overview Summary Flush the air and other non-condensable gases out of the copper line set and indoor unit Alternative for the inefficient and expensive quick-connect line sets Cost-effective, simple, and quick evacuation Perfect for most people and installations Description Pioneer KWIK-E-VAC is...

www.pioneerminisplit.com

 

[Short_Shot]

The can contains Difluoroethane and is designed to displace everything else in the lines. R410 contains Difluoroethane so I assume the amount left in the lines will not effect the system once you release the factory installed R410 from the outside unit.

To clarify, this would not work for a completely uncharged setup. This is aimed at the mini split units that come pre-charged, but the line set is not.

Oh.

Ok I saw the "liquid coming out" part and just assumed it was hydraulically displacing everything and that was that.

I think I get it now.

Thanks for the knowledge.

 

[labeeman]

Most DIY Kits come with coils of tubing precharged so no evacuating is needed, making the connections open up the ports letting refrigerant flow.

you’d just need to coil up the extra tubing if you only need 6’ but have 20’.

If you want to cut and reterminate for a clean look that when you should higher a company to properly purge the system and recharge.

I wish they did only one or two do come with fully charged lines the rest come with lines that you need to get the moisture out and pull a full vacuum to do that. Also, most get out of their warranty by requiring that a licensed AC man do the work for a DIY install.

 

[DerpsyDoodler]

Ok, I have watched videos till my eyes are crossing and my mind is numb!
I guess i'm just that dense!!
I am installing a 12000 BTU mini split in my Cargo Conversion Toy Hauler. I have a small 110v fridge (Dormer style) and the Mini says it pulls 9.1 AMP (At startup) and reduces down after room temp gets where it satisfies the thermostat. It then cycles on and off.
My question is, if I install 1800 watts of solar on the roof and have 400ah of Lithium Ion, Will I be able to run it 24/7?
I know there are calculators and other sources out there, but I just need some advice on whether I'm headed in the right direction or just full of crap!! Could be the latter. LOL

I have 1500 watts of solar and about 544ah useable @24v. i can easily go through a full night (even 2) with my mini-split set to "silence" (this is a diy mr cool minisplit, 22 seer). When the unit runs on inverter during the day, i've never seen it pull more than 45a (technically less, because the system is also powering some LED lights, computer electronics, a bluetooth speaker, and phone charging, all estimated to be a total of about 3a max more like around 2). My 1500 watts of solar is plenty to power the unit during the day, maybe with a minimal draw on the batteries or a minimal charge depending on solar conditions. I will have to use a generator (autostart) or shore power to effectively keep the batteries charged, but all in all, the system will be useable, will decrease my reliance on fossil fuels, and i can increase my solar footprint as time goes on.