I am going to try a DIY mini-split!

[jpwhit]

To coil or not to coil.

Tosot says you cannot change lineset length without adjusting freon levels. We coiled the excess lineset on our Tosot horizontally underneath the condenser unit.

Pioneer says you can reduce the length of their 16' linesets down to 10' without adjusting freon levels. We shortened the lineset on our Pioneer install from 16' to 10' and didn't coil.

I've always wondered about this claim about oil being trapped when the lineset is coiled vertically. In some installations the linesets can be run vertically up a wall sometimes as much as 20-30 ft. Gotta wonder how a long vertical run like that compares to a few, short up and down coils of excess lineset in terms of oil flow?

There is almost always a tolerance of lineset length on a minisplit that has a variable speed compressor. That's because you have to have a fairly large accumulator in the system to prevent liquid refrigerant from entering the compressor at all compressor speeds and temperature variations. They size that accumulator to also handle a fair amount of variance in line set length.

Large vertical runs don't cause oil to be trapped, but they can cause the opposite, they can cause too much oil to be pushed too quickly back towards the compressor. Most minisplit manufactures will recommend putting a dip in the lineset if the vertical drop is over a certain distance to intentionally create a small oil trap.

 

[jpwhit]

How much pressure do you think would be good enough to purge, and pressure test? I was thinking 200 can't find any pressure ratings in the book for Pioneer.

I think anything between 150 and 250 would be fine. R410A system typically have to have a max pressure rating in the 300-400 psi range. But I don't think going that high is needed and it takes a lot of nitrogen. Funny you say 200, because that's exactly what I typically use on a minisplit.

 

[jpwhit]

As far as flushing I'm assuming your referring to this stuff RX-11 $59 a can. I thought I read on their website not to flush it through larger components like a receiver recommend disassembling. My guess is that solvent would get trapped in the head unit now I have a bigger problem. Had this happen on a Honda flush got trapped in a rear evaporator. It's on the 3rd compressor removal drain and refill with PAG almost got all the flush out still smells little like flush. It diluted the oil still was good enough not to cause damage to the compressor.

Yes, but I use the liquid Pro-Flush when I've converted R22 systems to R410A. I always assumed they say not to run through large components because they want the solvent concentrated in the lineset you're trying to clean. But having it get left in the components seems like a potential problem too as you say.

 

[k490]

If you do the nitrogen purge you're proposing and don't get any oil out, then I think you're good to go.

Purged from the head unit liquid side connection point where it goes into the wall and nothing came out of the vapor line on a paper. No mineral oil in the head unit pressure tested to 200 PSI no leaks held for 30 minutes, and passed bubble test. Vacuumed with my new Robinair pump down to 110 microns closed the valve and drift tested for 10 minutes it came up to 240 microns. Opened the service valves and then put the schrader core valve back in powered up the unit and I get nice cold air. I can't believe how quiet this inverter outdoor unit is. I thought it wasn't even running the fan makes hardly any noise. What a difference then my 4ton goodman on my roof it's even less noisy then my old piston compressor was sounded like Harley running on my roof. Amp meter says about 5 amps at 240V about 1200 watts what I expected it's 103F 33% humidity right now. That isn't bad compared to my 5k window unit in the shed pulling about 1000 watts. 2 1/2 times larger unit pulling only 200 watts more. I will take some more measurements if we hit over 110F were almost half way through August usually the 110F are behind us now.

Still need to do some more work on the lineset cover I'm going to cut a slit down the flex cover came with the set so I can put it over the last section going to the ODU and take it off easily no need to rap the lines everything will be covered.

 

[OTRwSolar]

@k490, great job (and recovery)! Looks good.

You mentioned the Pioneer outdoor unit was really quiet. Totally agree. Even when it's pulling max current (8-9a/240v) our 18k Pioneer is quiet as a button. I might add it only weighs 70 lbs. Compare that to our 18k Tosot outdoor unit that weighs 115 lbs. and runs significantly louder.

 

[k490]

Took another amp reading with my Kline meter 4.82 amps at 240V 112F outside 21% humidity. Garage temp about 88F this is a 12k unit should work great with the EG4-6000xp inverter.

 

[Rocksnsalt]

All this sounds like so much fun.
Not.
I’m going to be sure to get something like an eg4 or mr cool diy ready unit. I don’t need more headaches and more specialized tools to spend cash on, use once or twice, then take up space forever.

So thank you for reinforcing what I already knew!

 

[Danke]

All this sounds like so much fun.
Not.
I’m going to be sure to get something like an eg4 or mr cool diy ready unit. I don’t need more headaches and more specialized tools to spend cash on, use once or twice, then take up space forever.

So thank you for reinforcing what I already knew!

I don’t have experience with mini splits. But how long do the ones from China last? I have my doubts someone would only need those tools once or twice. Mitsubishi? maybe.

 

[k490]

Just as a reference I took a amp reading off my 4 ton Goodman which is a regular run of the mill rooftop heat pump it is pulling 20 amps at 240. Reality is when it's 108F outside both pull the same power. 12000 BTU or 1 ton is 4.82 amps at 240v take 4.82 x 4 19.28 amps scale it up get the same power as low budget Goodman ducted heat pump.

I only needed the extra tools because I made the mistake of opening the valve to the vacuum pump after it was shut off which can lead to getting dirty mineral oil into the AC system which its not compatible with. EG-4 you don't need all these tools lines come pre-charged from what I know.

I admit I can get carried away with buying tools I don't need. I just went down the rabbit hole with HVAC I guess now I need to rent out these tools recoup my money.

 

[sunshine_eggo]

All this sounds like so much fun.
Not.
I’m going to be sure to get something like an eg4 or mr cool diy ready unit. I don’t need more headaches and more specialized tools to spend cash on, use once or twice, then take up space forever.

Watch the EG4 hybrid units. The 1 and 2 ton share the same MPPT, and it's notably undersized for the 2 ton.

 

[Rocksnsalt]

I don’t have experience with mini splits. But how long do the ones from China last? I have my doubts someone would only need those tools once or twice. Mitsubishi? maybe.

I don’t have experience with mini splits yet either.

But am I mistaken?
I’m pretty sure all mini splits are made somewhere in asia, with considerable content of chinese parts. If made elsewhere, the use of chinese parts / components is still likely significant.

How often do other compressor equipped items such as standard ac units and refrigerators need this type of work? And Auto AC?
Mine in the past, none, except for a very old refrigerator.
(He said while knocking on wood)

Of course past performance is no guarantee of future results, and ymmv.

 

[Danke]

I don’t have experience with mini splits yet either.

But am I mistaken?
I’m pretty sure all mini splits are made somewhere in asia, with considerable content of chinese parts. If made elsewhere, the use of chinese parts / components is still likely significant.

How often do other compressor equipped items such as standard ac units and refrigerators need this type of work? And Auto AC?
Mine in the past, none, except for a very old refrigerator.
(He said while knocking on wood)

Of course past performance is no guarantee of future results, and ymmv.

I have old appliances are still working fine. But it seems newer ones, as people have observed here also, do not seem to last very long. Refrigerators, washing machines, water heaters,air conditioning units, etc. Companies like Mitsubishi might outsource some of their manufacturing, but I think their parts and quality control is probably better.

 

[pvdude]

all mini splits are made somewhere in asia

The Mitsubishi I received was made in Mexico, hope the QC was good for all the Chinese parts.........
(Suspect Mitsubishi has manufacturing all over the world, parts from anywhere & everywhere)

 

[OTRwSolar]

All this sounds like so much fun.
Not.
I’m going to be sure to get something like an eg4 or mr cool diy ready unit. I don’t need more headaches and more specialized tools to spend cash on, use once or twice, then take up space forever.

So thank you for reinforcing what I already knew!

I don’t have experience with mini splits. But how long do the ones from China last? I have my doubts someone would only need those tools once or twice. Mitsubishi? maybe.

k490's mini-split experience isn't typical. Most mini-split installs go much smoother and only require a minimal amount of equipment which can sometimes be rented locally or purchased off Amazon for less than $200.

All the perceived hassles of vacuuming a mini-split lineset are way overblown IMO. Vacuuming is the least of your worries relative to the rest of the installation. Like a lot of things you attempt for the first time, once you get over the fear of the unknown, you typically find it's a lot easier than you thought.

If you don't mind spending almost double the money for a mini-split with precharged linesets so you don't have to vacuum, or double the money for a xyz or zyx based on their (perceived or real) reputation for quality, by all means that's your choice to make.

For what it's worth, the low prices you see on some mini-splits are not always indicative of quality, IMO it's more of a reflection of how efficient mini-split production has become due to the huge, on-going, worldwide market demand for mini-splits. The US has only recently embraced mini-splits. The rest of the world embraced them many, many years ago.

 

[k490]

Pioneer includes the flare seals some nylog I was impressed with those just snugging them with couple of wrenches I was able to seal them to 200 psi with the nitrogen test. If you don't want to invest in a torque wrench these seals are the way to go with the flare fittings. Vacuum for 30 min shut the valve if you have a manifold gauge let it sit for 30 minutes come back check it see if -30 PSI has moved any not going to find small leaks. Also check the flares with bubble test by cracking the liquid side service port tiny bit for 1/2 second close it after you vacuum. Then check the flares with soapy water see if there is any bubbles. This is what the Pioneer manual says to do once check the flares can go ahead and open the service valves all the way.

 

[Recovering EE]

Took another amp reading with my Kline meter 4.82 amps at 240V 112F outside 21% humidity. Garage temp about 88F this is a 12k unit should work great with the EG4-6000xp inverter.

My 6000XP with 6.4kW of PV is having no problem powering a EG4 12k mini-split, along with about half of my house. It, and two EG4 WallMounts, are easily offsetting about 20kWh per day, with a healthy reserve. The local grid is becoming more and more unreliable, and our local climate is getting more and more humid.

It's about 85F and 90% humidity outside, and 72F and 50% humidity inside. 1500sf house.

 

[pvdude]

Made some progress today!
Air handler mounted, lineset stubs, drain, electrical whip all run through the concrete block wall.
The Milwaukee 3-1/8" carbide hole saw munched right through the concrete.

Sleeve I found on ebay is larger OD than all the ones on Amazon, fit the hole perfectly,
and all the pipes, conduit, insulation from the Mitsubishi went through w/o issue.

 

[Rocksnsalt]

My 6000XP with 6.4kW of PV is having no problem powering a EG4 12k mini-split, along with about half of my house. It, and two EG4 WallMounts, are easily offsetting about 20kWh per day, with a healthy reserve. The local grid is becoming more and more unreliable, and our local climate is getting more and more humid.

It's about 85F and 90% humidity outside, and 72F and 50% humidity inside. 1500sf house.

Ohhh the brutal weather in Huntington Beach lol.
Sounds like a great setup, but how on earth are you using over 20kwh a day in coastal so cal?
Mining bitcoin?

 

[Recovering EE]

Ohhh the brutal weather in Huntington Beach lol.
Sounds like a great setup, but how on earth are you using over 20kwh a day in coastal so cal?
Mining bitcoin?

Mini-split at night (Has its own dedicated PV during the day.): 4kWh
Garage vent fan (to keep the 6000XP happy): 3kWh
Wine fridge: 2kWh
The rest of the half-house. (Lots of always on, very predictable loads.): ~11kWh
An EV and a PHEV: However much I can give them at 1kW, that won't overtax the inverter or 28kWh of batteries. Could be up to 10kWh.

I'm still figuring things out, and shifting circuits around.

 

[Rocksnsalt]

Mini-split at night (Has its own dedicated PV during the day.): 4kWh
Garage vent fan (to keep the 6000XP happy): 3kWh
Wine fridge: 2kWh
The rest of the half-house. (Lots of always on, very predictable loads.): ~11kWh
An EV and a PHEV: However much I can give them at 1kW, that won't overtax the inverter or 28kWh of batteries. Could be up to 10kWh.

I'm still figuring things out, and shifting circuits around.

Ok that makes a bit more sense with the EV / PHEV.

 

[k490]

If I set it to eco mode amp draw goes from 4.69 to 3.14 amps I can't really feel a difference seems to push the same amount of cold air. I did hear the condenser unit slowing down. No difference in current with turbo mode on or off turbo mode makes the indoor unit fan blow more. Ill be leaving it in the eco mode from now on. There is a way to connect it to Wireless, but I'm not going to bother with it being in a garage maybe at a later time.

4.69 amps 240V 1125 watts
3.14 amps 240V 753 watts

 

[Prefersdirt]

Yes.

Btw, I use a $540 9k unit from Amazon for my solar shed. Working very well so far. Uses about 400w, I have it set at 80 degrees and it usually maintains at 77.

Has a WiFi app so I can control it remotely and the Wi-Fi app also tells me the temp in my solar shed

which one are you using?

 

[1201]

which one are you using?

230v della 9k btu from amazon

 

[Plum Crazy Rob]

The 1 and 2 ton share the same MPPT, and it's notably undersized for the 2 ton

I find you are usually spot on. Can you expand on this a little what you mean by undersized?? Thx

 

[sunshine_eggo]

I find you are usually spot on.

Careful. That sort of talk might go to my head.

Can you expand on this a little what you mean by undersized?? Thx

24000BTU/h / 20SEER = 1200W

SEER has "mushiness" in it, and it may not even be remotely appropriate for your climate.

EER is a better estimate of typical MAX power consumption because it's a defined test.

EER of even high SEER units tends to be notably lower.

24000BTU/h / 12 EER = 2000W

Thus the 2 ton at max output is going to need 2000W of power.

If the goal is to maximum your PV, you want 3000-4000W of available PV so that you can produce the 2000W for a significant portion of the day.

The MPPT of the 2 ton and 1 ton are the same, and they are both limited to about 2000W of power. The MPPT is both voltage and current restricted to the point that it's actually challenging to get 2000W on it acceptably without just the right combination of panels.

Putting 2000W on the 1 ton unit would be about 2X the consumption of the 1 ton, so that's a pretty good way to get lots of PV-only run time.