Mini split - multizone vs individual sets???

[Stewfish]

Whats more effecient a 2-5 multi zone outside 18k btu w two or three 9k btu wall units or 2 or 3 individual 9k units you can turn off and on individually. I worry 9k wont be enough on really hot days for the living room/kitchen and I may want two wall units down the road, one on each end of the living room and one in the bedroom. More than likely it will just be 1 in the room and 1 in the living room/kitchen. Wouldn't efficiency drop if I add three 9k wall units to one 18k outside? Then if I'm running just one wall unit I'm waisting power running the 18k outside unit w only 1 wall unit. I will have about 4kw spare power unused currently to run the system during the day after batteries are charged around 9am. I have 28kwh battery and will be adding a windmill for on top of my hill where the cabin will be mainly to get heat at night in the winter.

Example. I only need to heat the bedroom at night until we wake up. Then Alexa or a phone app could auto start the living room wall unit to heat for the day. So all night the one bedroom unit will be running the 18k btu outside unit all night vs an individual 9k unit... But maybe it will heat better nc its a 18k unit thus run on less power?


I'm also looking for the best place to buy 120v high seer/ best bang for buck mini splits. I'm not sure the low seer Amazon prices are good anymore. Signature solar doesnt have them anymore. Where is a good place?.I'm hoping for 24 seer or better and -20f based on where I live.

An no over hyped Mr Cool brands.

Europe and Central/south america have been using well priced Midea, daikin Pioneer and C&H for decades and they last forever. So why buy a cheap Chinese MR Cool. If I wanted cheap I would get an innoviar 38 seer for $1300 - Just saying.

I saw these:

Cooper hunter 25 seer -22F $1200 https://www.minisplitwarehouse.com/...-heat-pump-ac-cassette-ducted-console-options

Midea 2-5 zone with -22f. I'm wondering if its cheaper down the road as I finish out rooms or on a really hot day if I should just have a multi zone since each wall unit is only $300-500 each. But then what will power usage be like? I'm assuming with the smallest 18k btu outdoor and only one 9k wall unit you will have more wattage used but if you do two wall units then the the single outdoor and two indoor is more effecient than two of each.

MIDEA Custom Multi Zone Mini Split Air Conditioner Hyper Heat Pump: Cassette, Ducted, Ceiling Floor

This Midea Hyper Package Includes: (1) 'Default' 2 Zone Outdoor Unit -You Can 'UPGRADE' T he Outdoor Unit to a larger one- DLCMRA Features Include : Heats & Cools ( -22F / -13F ) Basepan Heater ( Built in) Gold Coated Coils 7yr Compressor 5yr Parts Warranty Specifications Brochure When '...

www.minisplitwarehouse.com

Senville SENA-09HF-16is is 28 seer heats down to -20F for $1099.

 

[Bobert]

Pro

You can get better seer ratings with multiple units. You get redundancy with multiple units.

Con

I expect you will have greater idle power consumption with multiple units. You need more space outside for multiple units.

 

[jberger]

Actual efficiency drops on multi-split units, the cooling loop continues to cycle through all the heads, even when only a single head is calling for heat/cool. It's hard to get the highest efficiencies with multi-splits because they are rarely all hitting the magic marks on the efficiency curve. Some are running 80%, others 20%, others don't need any cooling at all but they are still in the cycle loop, etc.

If you really need -20F heating, then you should be looking hard at Mitsubishi, Fujitsu and Daikin. They have proven hyperheat style solutions, in market, for years, not just spec sheets and youtube videos.

Funny you talk about MR Cool being cheap Chinese while praising Midea/Pioneer/C&H, etc. I don't think you are understanding where these brands are made or who is rebadging who. Most of Mr. Cool is rebadged from GREE, and GREE has about 30% of the worldwide market.

The largest component sources are in china, so that is where most of these units are manufactured. Do not think you are buying multi-decade lasting equipment, parts availability will be the end of life for most of this stuff as the complexity is constantly increasing and regulations are forcing constant improvements. The parts are constantly being obsoleted. The older gear will be throw away stuff when it fails or needs a specialized part.

You can have a Manual J performed to tell you how much cooling you need for the spaces.
https://www.energyvanguard.com/ offers a 3rd party engineer service for this exact need.

 

[Stewfish]

Yes, Gree has also been used around the world for decades and I have seen these brands sold in grocery stores in the rest of the world, and are easily install by any person with the tools. In american you are paying more for marketing and the AC industry to install it. What's the % that midea sell internationally, probably 60% including all the rebadges.

Now to get to my second point where is a good place to get decent prices.

Santan Solar is the place to get good prices on solar panels bc they deal with bulk. What about mini splits?

 

[Solar Guppy]

What about mini splits?

I have bought mine from https://iwae.com/outlet/ and always get scratch and dent. Just put a 9K Mrcool in the Garage, just over $600 delivered including the install kit. The condenser has a little rash on one foot, everything else is new in the box.

I also have a Mr Cool 9K unit for a porch and the home is the MrCool 24k/36K universal, though I use a regular lineset from condenser to the air handler ( this is s ducted system ). Cost wise It was about $1700 for the universal system and it performs very well, much better than the 2-stage York it replaced. I also replaced air handler PSC motor with an ECM, with the controller about $500. This gives me 2 stage air flow tuned to the duct work of the home, much better balance and comfort.

I use these so there is no peak motor loads for the backed up loads, near whole house with the Solis 5G HVES

 

[Shawn Hayes]

We just finished up our off grid build. We have approximately 1900 heated sqft. I did a fair amount of research based for my particular build/circumstances and battery size. (16s4p)
We chose a Fujitsu 36K-BTU Mini split outdoor unit, instead of individual room cassettes, we opted for a traditional air handler that was paired with the mini split condenser.
In our case, having so many cassettes would be more inefficient than doing an air handler. Depending on your specific case and circumstances, that may not be the most efficient for you. However it was for us.
We are extremely pleased with the performance of the system so far. Having an air handler distributes the cool evenly all over the entire house.
On good sunny days I will drop the AC to 73°, but closer to sunset I will bump it up to 75°.
I have noticed that during the middle of the night, my unit will pull about 400 W when it spikes and runs a cycle and then shuts off. (See photo, note: only pulling about 150-175 watts when unit is NOT running)
Another upside for us, was in the winter time, if we ever needed to use our fireplace, we could use the air handler on a low fan speed setting to help circulate the fireplace heat to rooms furthest from the fireplace.
Maybe not as efficient as you may want/need but my 2-cents based on my experience this far.....

 

[hwy17]

Just installed a 27k/18+9+9 mrcool diy multizone, and pretty quickly realizing I would recommend individual units to anyone else.

If you intended to have all zones on all the time maintaining temp it could probably work out, but this thing doesn't really seem to want to turn down below a kw even though it supposedly can. Heating one bedroom to 65 (30f outdoor) with a 9k unit overnight the 27k outdoor unit is cycling between on and completely off and is achieving maybe 600w average draw? Not terrible, a bit more than half what a space heater would draw for the same. But I think an 1:1 unit could do better.

 

[galstaf]

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[galstaf]

I have installed about 7 units so far myself at friends and family houses, rebadged Chinese units. I would personally recommend individual units.
1. Less expensive per BTU (bought from eBay seller Senville)
2. More redundant. If a single unit fails you are not totally out of conditioning.
3. More control over specific areas.

I often leave the air handler (fan only) in place to filter and move the minisplit conditioned air round the property. The 18000 BTU units were low cost enough to have a backup system on hand for parts if any of them fail (none so far!), and are pretty easy to install. Buying the vacuum pump, line bender, sealing grease and a pipe cover kit is easily covered by not paying some HVAC guy to install it for you. Plenty of videos on YouTube to walk you thru the process. Install two or more systems and you are way ahead!

 

[NEpowerandlight]

It seems the best place for multi zone units is in a large open space. I have a 2 zone Daikin 18k unit with a 9k and 15k indoor units. They cover my living room dining room and Kitchen which is one big open area. By putting one indoor unit in the dining room/kitchen area and the other in the living room area I believe I get more even heating and cooling across the entire space vs. 1 indoor unit. It's a hyper heat model and totally protected from wind rain and snow as it lives under my covered and skirted deck.

I have a 12k Innovair 30 SEER unit with hyper heat that takes care of the master bedroom and bath.

As others have said they are easy to install but their are some important considerations. I selected Daikin because it's supposed to be a higher quality unit and it comes with a 12 year warranty which the longest I saw of the manufacturers. However you only get the 12 year warranty if a licensed HVAC guy installs the unit.

Also both units qualified for a rebate from my electric company, $400 each. But again only if installed by a professional. So I made a deal with a local HVAC guy to just connect the line sets and test the system. I installed everything including the electric connections from the panel. At the end of the day the rebates pretty much covered the HVAC guy and I get the full warranties on both units.

So far the 30k combined BTUs from the 2 systems keeps my 3 bedroom two bath 1500+ sq. ft house very comfortable.

Looking at my hourly electric usage on the coldest night so far in NE PA (18F) . Between midnight and 7am the 2 mini split systems, electric hot water heater, refridge, freezer and some LED lights average about 500 watts consumption per hour. I keep them all set to 68F during those hours.

 

[42OhmsPA]

Looking at my hourly electric usage on the coldest night so far in NE PA (18F) . Between midnight and 7am the 2 mini split systems, electric hot water heater, refridge, freezer and some LED lights average about 500 watts consumption per hour. I keep them all set to 68F during those hours.

Thank you for this, blows my mind... My coal stove draws more when the big convection blower I added kicks on. I think it will be my last winter on coal, especially with today's prices.

 

[NEpowerandlight]

Thank you for this, blows my mind... My coal stove draws more when the big convection blower I added kicks on. I think it will be my last winter on coal, especially with today's prices.

It blows my mind as well. I expected the 2 mini splits systems to draw more than 500 watts per hour while making heat. I'm anxious to see how they perform when temps get down to near 0F.

Know all about coal here in Schuylkill county.

 

[tomy2]

I have bought mine from https://iwae.com/outlet/ and always get scratch and dent. Just put a 9K Mrcool in the Garage, just over $600 delivered including the install kit. The condenser has a little rash on one foot, everything else is new in the box.

I also have a Mr Cool 9K unit for a porch and the home is the MrCool 24k/36K universal, though I use a regular lineset from condenser to the air handler ( this is s ducted system ). Cost wise It was about $1700 for the universal system and it performs very well, much better than the 2-stage York it replaced. I also replaced air handler PSC motor with an ECM, with the controller about $500. This gives me 2 stage air flow tuned to the duct work of the home, much better balance and comfort.

I use these so there is no peak motor loads for the backed up loads, near whole house with the Solis 5G HVES

I checked out https://iwae.com/outlet/ and their prices are good, but the shipping makes them more than Amazon or Ebay

 

[NEpowerandlight]

I got my Innovair from https://powersaveac.com/

Free Shipping and install kit included

From what I understand they use Gree compressors which I also believe is what the Mr Cool units use.

 

[tomy2]

It blows my mind as well. I expected the 2 mini splits systems to draw more than 500 watts per hour while making heat. I'm anxious to see how they perform when temps get down to near 0F.

Know all about coal here in Schuylkill county.

That is very efficient, he says they are 30 seer, so they must have been pricey. I am looking at the Senville 900 for a studio I rent out. It is 20 seer and uses 700 watts,although it shouldn't be running constantly. It is $750. on Amazon.

 

[tomy2]

38 SEER Savings Electric Rate ($/kWh) vs 13 SEER $0.10 $0.15 $0.20 $0.25 $0.30 $0.35 $0.40
5 Year Savings $414.00 $621.00 $829.00 $1,036.00 $1,243.00 $1,450.00 $1,657.00 1
This shows that at my rate (0.35) , I could save $1243. in five years. But the initial cost would be close to that. And this comparision is based on about 8 hours a day, 365 days a year. That is probably twice the hours we would use it. I conclude that you are better off with a 20 seer unit, that will cost less than half what a 38 seer costs.

 

[NEpowerandlight]

38 SEER Savings Electric Rate ($/kWh) vs 13 SEER $0.10 $0.15 $0.20 $0.25 $0.30 $0.35 $0.40
5 Year Savings $414.00 $621.00 $829.00 $1,036.00 $1,243.00 $1,450.00 $1,657.00 1
This shows that at my rate (0.35) , I could save $1243. in five years. But the initial cost would be close to that. And this comparision is based on about 8 hours a day, 365 days a year. That is probably twice the hours we would use it. I conclude that you are better off with a 20 seer unit, that will cost less than half what a 38 seer costs.

I didn't get to worried about SEER ratings, my guess is they are like new car MPG ratings. Kind of close... I paid $1200 complete for theInnovair 12k, 30 SEER unit and got a $400 utility company rebate, which brings the cost down to $800. However I purchased the unit a year ago and currently the same unit is about $1500 with shipping and install kit.

I eliminated the lower cost Amazon units because while most reviewers were happy with the units, I've had HVAC guys tell me the circuit boards on many cheaper units are known to stop working. That's not to say the more expensive units don't experience the same problem from time to time. But I know on my Daikin unit the circuit boards are warrantied for 12 years instead of 1 year like most others. The Innovair unit only warranties the board for 1 year and the standard 5 and 7 year on the inverter and compressor. At the end of the day I don't see anything wrong with most of lower cost units Amazon sells. Hell as far as Amazon is concerned I'd be more worried about the thing arriving in one piece.

 

[Brett V]

I'm in Cumberland County PA and switched from a wood stove to a pellet stove last year. I have an older Pioneer 28000 btu mini split upstairs that needs replaced, it goes in to defrost mode frequently when the temperatures get below about 30 degrees. I haven't monitored power use but it could be better. I've also noticed power consumption in heating mode to be quite a bit higher than cooling. In my downstairs office, I have a small 9000 btu Senville unit and it heats the room even down to single digits. It's on a single 110v 15 amp circuit and probably uses less power than the blowers on my pellet stove.

 

[tomy2]

I didn't get to worried about SEER ratings, my guess is they are like new car MPG ratings. Kind of close... I paid $1200 complete for theInnovair 12k, 30 SEER unit and got a $400 utility company rebate, which brings the cost down to $800. However I purchased the unit a year ago and currently the same unit is about $1500 with shipping and install kit.

I eliminated the lower cost Amazon units because while most reviewers were happy with the units, I've had HVAC guys tell me the circuit boards on many cheaper units are known to stop working. That's not to say the more expensive units don't experience the same problem from time to time. But I know on my Daikin unit the circuit boards are warrantied for 12 years instead of 1 year like most others. The Innovair unit only warranties the board for 1 year and the standard 5 and 7 year on the inverter and compressor. At the end of the day I don't see anything wrong with most of lower cost units Amazon sells. Hell as far as Amazon is concerned I'd be more worried about the thing arriving in one piece.

Most of the brands only warranty parts, not labor. I saw a youtube thing, where a guy had a mother board go bad in three months and Senville sent him a new one. He wasn't a super electrician but he managed to install it in six hours. I would hate to have to do that, but atleast you know a mother board is not the end of the world

 

[Brett V]

Most of the brands only warranty parts, not labor. I saw a youtube thing, where a guy had a mother board go bad in three months and Senville sent him a new one. He wasn't a super electrician but he managed to install it in six hours. I would hate to have to do that, but atleast you know a mother board is not the end of the world

I think that's a result of the reality that finding an HVAC tech who will work on a DIY installed unit is unlikely at best.