What Mini-Split did you use, and Why?

[SolarScott]

Is that the Senville Leto that I see on Amazon for something like $800? I have been eyeing that.

I ordered the 12K and with extended warranty for extra $57 and free shipping it was 930 delivered I believer. It is supposed to arrive tomorrow. I have all electrical ready, just need to drill the hole in the wall......Seemed to have good reviews.

 

[hwy17]

I started with a 3 zone mrcool DIY 27k 18/9/9.

From that experience I learned two things:

1. Multizone designs have critical compromises and I will only ever purchase 1:1 units in the future.

2. The non DIY units are not that hard to commission and offer neater installs because you can cut the lineset to length and there is a much wider market of options.

For my brother next we went with an LG because he liked the brand and some specs better than the cheaper Daikins. Spent about $300 on vacuum pump, attachments, flare tool, and a gauge (no micron). We pressure tested with propane but I would be happy to use compressed air too and I don't believe the scare stories that it will contaminate the system. The vacuum pump sucks any moisture out.

 

[Bkord]

3 Mrcool diy mini split heat pumps. Cosco had them on sale for $1200 each. Easy to install and they heat and cool the whole house. They are very efficient compared to the old window unit we had. They are also very quiet.

 

[Solar Guppy]

How does that 9k work in your garage? My garage is the same sq/ft but I'm leaning between 12k or 18k that people keep telling me I might need.

I have R40 in the garage ceiling, insulated the door panels ( $300 kit at lowes ) and have had zero issues on maintaining temperatures. I don't know "your" people, but most just throw out "be safe" numbers.

My previous home I had installed a 3 ton heat pump for a 2600 sf home, again, just had good insulation in the attic.

If you keep the sources requiring BTU's at bay, it doesn't take much to maintain a temperature. An example is a walk in freezer, they have very small units, like the size of a window AC, but they have all sides, top and door insulated.

 

[Shimmy]

I have Mitsubishi Mr. Slim's in the house, and they have one characteristic that I cannot stand which might be relevant to you: the coil temperature is too low so they do a lot of latent cooling. (Aside from the bedrooms, my house is naturally ventilated. There are no vapor barriers between the conditioned and unconditioned spaces.)

The problem I have is that sometimes I just need a lower dry bulb temperature, and there is no need to dehumidify. Many garages have significant air leaks by commission or omission, so when it is humid you will use a lot more energy than the equipment will ever benefit from.

Controls on these mini-splits leave a lot to be desired, and there really isn't a way around them.

The tiny piece of advice I will offer is that you are better off installing 2 1-ton units rather than 1 2-ton unit if you need to run the mini-splits when their loads are going to be fairly low-- just shut off one of the two units and let the inverter have maximum turn-down on the other.

 

[MrM1]

I'm liking the EG4 / Deye ACDC solar mini splits.

Clearly not for everyone because of added costs of the direct DC solar, but they do really work on solar DC only very well.

They were my choice because I wanted to add AC to my solar, but with a 4k inverter it was going to require an inverter upgrade, and with my 24v system, going up in inverter meant going to 48v meaning battery upgrades, bms replacements, wiring changes etc.

Using the EG4s allowed me to keep my existing inverter. Cost for me was less with the 3 ACs and 18 panels than getting Non solar units and an upgrade to 48v inverter.

What I don't like about them
- warranty void if diy install. It's pretty stupid easy with right tools
- they don't auto sweep side to side
- no timer or sleep mode
- no scheduling
- I also don't like that when in solar only, if you get a lot of clouds, after about an hour the unit stops seeking for DC power and goes to sleep. You have to turn it back on to wake it up. But that's not a big deal if using both DC and AC. It will prioritize DC til it can't

Over all, happy.

 

[Nobodybusiness]

self-admitted Luddite

There’s a thing you don’t see very often.

 

[1201]

I started with a 3 zone mrcool DIY 27k 18/9/9.

From that experience I learned two things:

1. Multizone designs have critical compromises and I will only ever purchase 1:1 units in the future.

What problems did you have with multi zone?

 

[houseofancients]

https://www.amazon.com/Efficient-208-230V-Conditioner-Ductless-Inverter/dp/B0C4DFHTDN/?th=1

This Della Unit is a 12k BTU for $699 right now with a 21 seer rating. Thats pretty damn cheap lol.

looks very much like mine

 

[hwy17]

What problems did you have with multi zone?

It is very inefficient at driving a single zone, like if we only want to use the 9k bedroom head at night. It has to pump to all zones at all the time so my guess the cause is all the heat radiating out the top of the other units even though they're off. For just heating the bedroom it's barely cheaper than resistive bad.

Then, if you run multiple zones the outdoor unit turns up to meet the highest demand so if you have unevenly loaded zones like our living room 18k which demands full power when left on overnight, that causes full power to go to the other zones too. So the bedroom overheats. There is a setting to make the bedroom unit turn its fan off for 20 minutes after reaching setpoint which helps a little but doesn't solve it and you wake up freezing or boiling.

Lastly, it can't heat one zone and cool another. Sure you never think you'd do that until you get used to having them then spring rolls around and it happens, person on the sunny side of the house's AC errors out cause you decided to start heating up the living room on the cold side.

 

[1201]

It is very inefficient at driving a single zone, like if we only want to use the 9k bedroom head at night. It has to pump to all zones at all the time so my guess the cause is all the heat radiating out the top of the other units even though they're off. For just heating the bedroom it's barely cheaper than resistive bad.

Then, if you run multiple zones the outdoor unit turns up to meet the highest demand so if you have unevenly loaded zones like our living room 18k which demands full power when left on overnight, that causes full power to go to the other zones too. So the bedroom overheats. There is a setting to make the bedroom unit turn its fan off for 20 minutes after reaching setpoint which helps a little but doesn't solve it and you wake up freezing or boiling.

Lastly, it can't heat one zone and cool another. Sure you never think you'd do that until you get used to having them then spring rolls around and it happens, person on the sunny side of the house's AC errors out cause you decided to start heating up the living room on the cold side.

Wow sounds like it's really not ideal. I was looking into this for the granny pod. I think I'll stick to individual units

 

[RCinFLA]

A dirty little secret on many U.S. distributed mini-splits is they have poor power factor, high crest factor peak run current due to their cheap AC to HV DC power supply required for the three-phase variable speed compressor inverter driver.

EU regulations on power factor of appliances requires units sold in Europe to have power factor correcting power supplies. These regulations do not exist in most U.S. states so some manufacturers cut costs by removing the PF correction circuitry.

Unfortunately, the only way to tell is to measure the running AC power factor of unit. The manufacturers do not publish their AC power factor specs.

It is harder on a battery powered inverter to deliver high peak current crest factor loads and results in lower battery powered inverter efficiency. This is especially true for lower cost HF battery powered inverters.

 

[sunsurfer]

Allot of the cheap mini splits are the same manufacture, just different label. Look at the remotes. You are shopping for "after purchase" support FYI

 

[sunsurfer]

A dirty little secret on many U.S. distributed mini-splits is they have poor power factor, high crest factor peak run current due to their cheap AC to HV DC power supply required for the three-phase variable speed compressor inverter driver.

EU regulations on power factor of appliances requires units sold in Europe to have power factor correcting power supplies. These regulations do not exist in most U.S. states so some manufacturers cut costs by removing the PF correction circuitry.

Unfortunately, the only way to tell is to measure the running AC power factor of unit. The manufacturers do not publish their AC power factor specs.

It is harder on a battery powered inverter to deliver high peak current crest factor loads and results in lower battery powered inverter efficiency. This is especially true for lower cost HF battery powered inverters.

Reminds me of a youtube video I found where they built circuits to "Fix" low power factor. It involved capacitors and inductors but was a big improvement on wasted power.

 

[HighTechLab]

It is very inefficient at driving a single zone, like if we only want to use the 9k bedroom head at night. It has to pump to all zones at all the time so my guess the cause is all the heat radiating out the top of the other units even though they're off. For just heating the bedroom it's barely cheaper than resistive bad.

Then, if you run multiple zones the outdoor unit turns up to meet the highest demand so if you have unevenly loaded zones like our living room 18k which demands full power when left on overnight, that causes full power to go to the other zones too. So the bedroom overheats. There is a setting to make the bedroom unit turn its fan off for 20 minutes after reaching setpoint which helps a little but doesn't solve it and you wake up freezing or boiling.

Lastly, it can't heat one zone and cool another. Sure you never think you'd do that until you get used to having them then spring rolls around and it happens, person on the sunny side of the house's AC errors out cause you decided to start heating up the living room on the cold side.

This sounds like something might be wrong with the install/setup. Each zone has an electronic expansion valve (EEV) that meters the refrigerant to the coils that are in use (and prevents sending refrigerant to the ones not in use). The compressor is variable speed (and the condenser fan too) so it only should be running to meet the demand of the single head calling for heat. If the EEV is closed, how are you getting refrigerant flow in the zones not calling for heat?

But yes, not being able to heat and cool is certainly a drawback, because the reversing valve is upstream of the EEVs

 

[Robbert]

Here 6 mini splits. Different brands (Daikin, Gree and LG). Apart from design they all are good and perform good.

Installed the LG myself, but installation is not different from other units.

Be sure that you install an inverter. Inverters have a much lower start surge and are more efficient anyway. The LG in my garage draws quite some power since it's 'fighting' the heat produced by the inverter’s.

All mini splits are powered by my inverters and never had an issue with high start currents.

Will install a 7th mini split. That will be Daikin. Daikin seems the most quite one I have.

 

[sunsurfer]

Personally, I don't think they are much more efficient then a cheap window unit. We need to pick either CEER or SEER. I prefer CEER rating. I went mini split route for a quiet and lower output. Soft start is nice. Also, shoulder season heating. I'm hoping someone does a CEER test on one of the cheap Chinese units some day.

I have a della 9K, it drops down to about 190-140watts when its just creeping along. Perfect for taking the edge off without sucking the life out of the batteries for the over night.

 

[hwy17]

This sounds like something might be wrong with the install/setup. Each zone has an electronic expansion valve (EEV) that meters the refrigerant to the coils that are in use (and prevents sending refrigerant to the ones not in use). The compressor is variable speed (and the condenser fan too) so it only should be running to meet the demand of the single head calling for heat. If the EEV is closed, how are you getting refrigerant flow in the zones not calling for heat?

But yes, not being able to heat and cool is certainly a drawback, because the reversing valve is upstream of the EEVs

Interesting. I didn't know the EEVs could close like that. The unused zones lines definitely get warm, maybe not quite as hot as the in use zone. That could be copper conductance heat though. If the EEVs can close what is the point of the branch boxes sometimes used on Mitsubishi multi zones?

It's possible that my unit is internally malfunctioning unnoticed. But I have heard the same experience from other rebadged Midea unit users on other forums about heat radiating out of other units.

It's also possible that I'm just wrong about the cause, and the poor efficiency is more a result of the poor pairing of a 27k outdoor unit to run a single 9k head at low loading.

I definitely can't get the 200w, 300w turn down that a single zone 9k unit can. The 27k seems to pull about 800-1000w minimum. I would think that cycling would still help but I don't have detailed monitoring to say how much cycling it does in single 9k operation.

I also have a sneaking suspicion that the DIY connectors affect efficiency? Not sure about that.

I'm considering seeing if I can remove the DIY connectors (6) from the system and convert to compression. If that doesn't help I'm thinking of getting a 24k pioneer WYS head for it and using it basically as a single zone.

Edit: The lines definitely get warm all the way to an unused unit. But not as hot as an in use. I suspect that the oil return cycle opens all EXV's.

 

[sunsurfer]

Anybody have any experience with the Della brand Mini Splits? I can't find a website or any spec sheets on their units.

They are just rebrands like all the others. The 12K with the small display remote I believe is the previous generation. Line set is pretty short. The large display remote 12k should have the longer line set and is the newer style everyone is selling. The 12k(small remote) has an exposed circuit board. I'm going to build a shelter over mine. I can see the board from the outside!

I have a 9k and a 12k(small display). The 9k seems like a better build. They both work fine but I know it is cheap chinese.

 

[Lt.Dan]

We need to pick either CEER or SEER. I prefer CEER rating

I personally am looking more at the EER rating. Since it will be in the hottest part of the home all the time, and constantly battling the heat my inverters will be producing. SEER and heat ratings mean nothing to me, personally.

They are just rebrands like all the others. The 12K with the small display remote I believe is the previous generation. Line set is pretty short.

The 10ft line set is actually perfect for me, because the outdoor unit is literally going on the same wall as the indoor unit.

The large display remote 12k should have the longer line set and is the newer style everyone is selling. The 12k(small remote) has an exposed circuit board. I'm going to build a shelter over mine. I can see the board from the outside!

This is the circuit board inside the outdoor unit? That can't be very smart. Definitely will keep an eye out for that.

I have a 9k and a 12k(small display). The 9k seems like a better build. They both work fine but I know it is cheap chinese.

Is there any significant design improvements with the larger display remote?