Anybody know anything about mini-splits? [NA]

Jim K

Jim K

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The room above the garage in our new house is not air conditioned. It's a large room that serves as bedroom for our 3 youngest. It has its own furnace. It might be possible to run a duct up through the kitchen cabinets, but I'm thinking maybe one of those ductless mini-splits might be a cheaper and more effective alternative.

I see them advertised on you tube all the time, but I don't want to base my purchase on that obviously. Seems like one that can also run as a heat pump in the winter might be cheaper to heat with than existing propane forced air furnace, at least until it gets really cold.

Anyone have experience with them? Are there good/bad brands, or do they all come out of the same factory in China?

The rest of the house is heated and cooled by a geothermal heat pump that's pretty efficient, so running a duct might be a more reasonable option, but with the size of the space I'm not sure a single duct would be enough. It's the size of a two car garage.
 
Mitsubishi, LG, Carrier, Fujitsu are all good. Compare efficiencies with price. In heat pump format they can still provide some level of heating down to zero degrees F. If you are in a northern climate with a lot of sub zero temps, you would probably need some form of supplemental heat for the colder days.

A key issue is making sure someone in your area us familiar with whatever brand you select. If you contract out the purchase and install, this will probably not be an issue. If you intend a diy install this would be a concern.

To state the obvious, you need to have one unit in each room to be effective. Most of these manufacturers have an option to connect up to two or three room units to a single outdoor condenser.
 
We got Fujitsu units for the basement and attic, sharing a single condenser. It had an infant mortality issue that was repaired under warranty, but took a while to resolve due to 2021 supply chain issues. Other than that, we've been happy; those parts of the house are now comfortable year round. Since then, our HVAC people have started recommending Carrier.

Ted, which brand did you get?

https://www.pilotsofamerica.com/community/threads/thinking-about-a-mini-split-in-my-garage.112615
 
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Following. Been considering one for the hangar as a way to flare off excess solar panel charge and preserve battery life. It's that or a bitcoin miner, and I know which I would find more refreshing to work near :D
 
I've never owned one but have spent a lot of time in a lot of different places with them. They've always seemed to work well enough and aside form the sort of ugly box on the wall are pretty much not noteworthy....
 
I can't help you in sizing your system.

I have a 2 head minisplit system. Initially installed to provide AC rather than continuing to use window units or the R2D2 units on wheel. I've recently been using it for the heat function (when temps are above 35 deg F or so...)

The system I have was installed in 2014. Recently the cores developed a leak and were replaced (not under warranty of course). During the troubleshooting, the guy who installed the system in the first place noted that he was glad that my install was old enough that he was still using copper lines for the refrigerant. Newer installs used some kind of white PVC that doesn't hold up.

So, the main point of this post is to encourage you to make sure you get copper lines or make sure the PVC used isn't the old crappy type (sorry, I don't know which it was... I don't have it, so it wasn't particularly important to know which PVC designation doesn't work well)
 
We have a few at work, in IT rooms, enclosed porches, etc. All at least 4-6 years old, and seem to work well. Much better than the portable droids as mentioned above.
 
I have installed 2 mini-split units one in my house, and a second in my shop. I have been happy with both units. Both are Senville brand from eBay, very likely not as good as the above mentioned brands, but they were easy enough to install, and have performed well for several seasons.
 
Agree the Mitsubishi, LG, and Fujitsu ones are good (not knocking Carrier - just haven’t seen them much in research or direct experience).

I’d suggest getting the heat pump version rather than just an AC.

Probably not for your application but for a less critical area, the Mr Cool DIY ones are an option. I have one in my hangar and one in my workshop. They’re easy to install, work well (so far), and are a bit more affordable. Then again, if I have problems, it may be tough to find someone to work on them - not sure. (I say “less critical area” only because I don’t know their long-term reliability).

Depending on how humid your area is, sizing towards the smaller end is good: it will run more and therefore dehumidify better. Then again, most (including the Mr Cools) have a dehumidifier setting.
 
Lndwarrior said:
If you are in a northern climate with a lot of sub zero temps, you would probably need some form of supplemental heat for the colder days.
Click to expand...

Unless you live in New York, in which case the government is mandating them for heating.
 
Got a Carrier mini-split heat pump system in my shop/garage/garage attic (3 separate zones) overall about 22x30 feet. I don't generally try to keep everything at "room temperature" but I don't have any issues with capacity in the Detroit area. Dunno how the costs for electricity would compare with Propane.
 
Jim K said:
It has its own furnace. It might be possible to run a duct up through the kitchen cabinets
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Forced air furnace? Then you may well be able to use the existing ducts. Wall furnace? Not so much...

Brad W said:
aside form the sort of ugly box on the wall
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Now available are cassettes that mount in the ceiling, between joists. When turned off, it's a flush panel, that you can paint to match the ceiling. When on, the duct doors open to bring in room air and expel conditioned air.
 
PaulMillner said:
Forced air furnace? Then you may well be able to use the existing ducts. Wall furnace? Not so much...


Now available are cassettes that mount in the ceiling, between joists. When turned off, it's a flush panel, that you can paint to match the ceiling. When on, the duct doors open to bring in room air and expel conditioned air.
Click to expand...

How does it drain the condensate? Does it require a pump? I have an 80's vintage 3 ton Carrier central system that sound like a jet at takeoff power. I want to replace the system with something efficient, and more importantly, quiet. Bride hates the look of the mini split wall unit.
 
I’ve installed about 5 of the pioneer brand. In the several years they’ve been running, the only I had was one wonky board that we found bad out of the box. They cross shipped us a new one and they all work great.


I started installing when I got an offensive quote for a mini split.

I need to do 3 more next month at moms new house and intend to use the same brand


Sent from my iPhone using Tapatalk
 
Actually just started the paperwork to install 3 Mitsubishi units, with a total of 11 heads. (Doing the whole house, primary benefit is for A/C).
Most mini-splits these days are multi-stage (I think that was how it was described) systems which can operate efficiently at much colder temps than previously. The old advice was to have the heat pump cut off at 35F installers or higher, and switch to a backup system. Depending on the model, most companies seem to have lowered this between 17 and 25 degrees. Note: this is where efficiency drops off, very fast and you likely are better going with alternative heat, many will continue to operate even colder.

The local installers we had quotes from, all were planning to use a company called Eco Bee (Canadian I believe), for an integrated control system. With outside temp probes, the Eco Bee will automatically turn off the heat pump and use our existing gas heat when the temp gets below a specific set point. I am planning to go with 30, based on the current price point for gas and electricity (if gas prices go up, I might lower the set point).

Tim
 
I've installed three of them. Everyone loves them. Each of those were 18,000 BTU 22 SEER (1.5 ton) for a 900 sqft apts. They were installed in the living room and it heats/cools both bedrooms and kitchen (doors need to be open). Electric bills went down orders of magnitude and they put out nice heat and cooling. Mine are the cheap ones found on e-Bay and we are going on 5 years and no issues. I went from (4) 220 vac 20 amp electric baseboard heaters to one 220 vac 10 amp mini-split. I built scaffolding to run the lines up the side of the house in thru the wall (hole sawing thru a brick and block wall) of the second story. I'd say that was the most difficult part....running the lines between the units. Also, getting things to seal is another (before you release the refrigerant)....if you have to silver solder the copper.

Everything is gravity drained and hangs on the outside wall....

here's what I've used....and have high regards for the no name. https://thebestminisplit.com/producto/aircon-18000-btu-blue3/

1562248179107_blue3-1-150x150.png


I have two more 9,000 units sitting on a pallet in my garage. As soon as I can get my son to clear his car out of the garage these units are going into a spare bedroom and the garage.
 

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I’ve got 6.5 tons of Mitsubishi AC/heat pump mini split in the shop and another 15k BTUs in the garage. We went with their “hyper heat” units which I think are good down to -4F (or is it -13F? I forget). I’ve been very happy and have had no issues. Energy use is pretty low all things considered.

I would stick with the higher end brands, but I’ve known folks who’ve done the DIY specific mini splits (Mr Cool I think?) and have been happy. Mitsubishi you’ll need to solder lines and vacuum the system out as I recall. I paid for the install in all cases and it was worthwhile.
 
I've got a 4 zone Mitsubishi that is undersized for the house construction. When the sun sets, it's great. During the day time, middle of summer, it can't keep up. That is more on the bid than the system though. They are quiet and efficient, with variable stages to tune cooling effort to the differential. I didn't see any soldering going on, so that may vary with distance between wall unit and compressor.

I ran them heavily this winter vs natural gas which saved at least $50-100 per month where we warmed individual rooms vs the whole house. Agree with the above though - I have the regular heat pump and you could tell they aren't so hot (lol) below about 30F. Hyper X should be better but there will still be a point where it is burning more electricity defrosting the outdoor unit vs heating indoors.

I'm still trying to figure out a somewhat economical way of upgrading the house to have good cooling in the social areas and rooms, but Mitsubishi can get spendy very quickly. That said, I didn't observe anything that any HVAC installer couldn't handle so don't feel obligated to stick to the 'certified platinum installer' list. The install, replacing a Sanyo (aka cutoff and mounts reused*) had a range of quotes 9 - 20K even before Covid made things crazy.:rolleyes:
 
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They are the standard for air conditioning in Southeasst Asia where air conditioning is a thing, including most high rise buildings.

I echo Ted's comments. Buy a higher end Japanese brand. In Vietnam, in the scooter world, there is Honda and then there is everyone else. In the air conditioning world, there is Sanyo and there is everyone else. Here? Not as much carp is sold so as long as it it a name brand it will be fine.
 
The server room of my company is very small We have a Mitsubishi mini split that cools it It's kept that room at 67° 24/7 for 4 years without interruption
 
When dad built the house, he planned this to be unheated storage, so although it was insulated, it had no hvac. When he decided to finish it, he installed a forced air furnace in the closet with essentially no ducting. Might as well be a wall unit. It's a big room, so I'm thinking a duct big enough to heat & cool the space probably won't fit in the cabinet space I'd be willing to give up.

I appreciate all the comments. I'm sorely tempted to try one of the cheap diy units. Pioneer is one brand I've seen online. They're cheap and seem pretty simple to put together. Glad to hear a positive pirep on them. If it fails, I'm back to where I'm at now, which is with hot sweaty kids. They'll live. It'll probably even build character or something.

I think I'll get a quote from an hvac company first, which I suspect will send me straight back to the diy option. That's how pretty much all of my projects go, and the reason I get further and further behind every year.
 
My dad/neighbor just had 2 mini splits put in. One for his "sun room" and the other for the pool room underneath that a few months ago. The condenser is way bigger than I had imagined. Pretty clean looking, quiet, and seem to work pretty well. All in was a little under 10k which shocked me.

I was considering them for the apartment I'm building above my detached garage but balked when I heard the price. Went conventional and did all but charge it myself
 
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Sac Arrow said:
They are the standard for air conditioning in Southeasst Asia where air conditioning is a thing, including most high rise buildings.
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yesssir. It is also ubiquitous and the go-to choice in my native Caribbean. My folks' primary and secondary residences back home feature mini split units in every bedroom. It's the only way my Anglo wife survives the humidity when we travel down lol.

It's primarily due to the the cost of electricity being prohibitive down there, and the homes being concrete (poor insulator). As opposed to most ducted central units feeding into insulated foam and stick houses common in the states, these ductless units feature variable speed compressors, which greatly improve electric consumption in these non-insulated concrete homes. Modular AC use across sections of the home is a must due to cost, the rest is copious fan use and natural building ventilation.

Second to coquí frogs, I know I'm home when I see that kitkat bar contraption on the ceiling line of my room. :D
 
Friend of mine got some retired solar farm panels and one of these units: https://signaturesolar.com/eg4-hybrid-ac-dc-solar-air-conditioner-1-ton/
It takes solar direct and/or grid power. The bluetooth app shows <500 running watts, and grid/solar consumption. Seems to run fine off 3 panels, if he adds a server rack battery he can probably go overnight without the grid.

Seeing his setup finally made solar real to me. Free a/c for $2k is a game-changer.
 
dcat127 said:
Unless you live in New York, in which case the government is mandating them for heating.
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To be fair, not getting a heat pump version is silly; the efficiency of moving heat rather than generating it by any means other than solar is fabulous.
 
@Jim K

There are two parts to the cheap units versus the high end.
1. Reliability
2. Heating Efficiency

Unless your existing heat is electric resistance, the payback for the efficiency will be never. So I would suggest focusing on the reliability aspect. That means gravity drain for the condensate at a minimum (the water pumps are load and notorious for breaking down); and getting a brand which is focused more on A/C than heat.

If you dig into the details, multi-stage heat pumps expand the efficient range of temperatures for which the heat pump operates; and this expansion is significantly more in the cold direction than the hot direction. Therefore, you might be able to go with a much cheaper single stage heat pump. Depending on your thermostat solution, it might be able to control both units, or you may have to do so manually.

Last point, I am in MA. Between state and federal incentives, it was actually cheaper for me to go with a high end Mitsubishi solution than a cheaper one.

Tim
 
Dad put one in the 40x60 shop we/he built. It works like a champ as far as I know. No idea on brand or capacity, but can get details next time I'm over there. I was surprised how well it works and how quiet it is.

Our 'over the garage' room is less than ideal, too. It technically is plumbed into the HVAC, but sitting over the un-climate controlled garage which faces west, it turns into a sauna in the summer evenings. I've been tempted to put some sort of small wall unit it just to take the 'edge' off in the summer and winter, so I'm curious to see what you come up with.
 
tspear said:
Last point, I am in MA. Between state and federal incentives, it was actually cheaper for me to go with a high end Mitsubishi solution than a cheaper one.
Click to expand...

hmmm...that's a good point. I think our electric utility has rebates available through approved installers. That might take the edge off getting someone else to do the work.
 
hindsight2020 said:
yesssir. It is also ubiquitous and the go-to choice in my native Caribbean. My folks' primary and secondary residences back home feature mini split units in every bedroom. It's the only way my Anglo wife survives the humidity when we travel down lol.

It's primarily due to the the cost of electricity being prohibitive down there, and the homes being concrete (poor insulator). As opposed to most ducted central units feeding into insulated foam and stick houses common in the states, these ductless units feature variable speed compressors, which greatly improve electric consumption in these non-insulated concrete homes. Modular AC use across sections of the home is a must due to cost, the rest is copious fan use and natural building ventilation.

Second to coquí frogs, I know I'm home when I see that kitkat bar contraption on the ceiling line of my room. :D
Click to expand...

I don't know that mini splits were even a thing when I lived there in my high school years. But there wasn't much of an advantage over window mount units since every room in the concrete base housing had a window anyway.
 
Jim K said:
When dad built the house, he planned this to be unheated storage, so although it was insulated, it had no hvac. When he decided to finish it, he installed a forced air furnace in the closet with essentially no ducting. Might as well be a wall unit. It's a big room, so I'm thinking a duct big enough to heat & cool the space probably won't fit in the cabinet space I'd be willing to give up.

I appreciate all the comments. I'm sorely tempted to try one of the cheap diy units. Pioneer is one brand I've seen online. They're cheap and seem pretty simple to put together. Glad to hear a positive pirep on them. If it fails, I'm back to where I'm at now, which is with hot sweaty kids. They'll live. It'll probably even build character or something.

I think I'll get a quote from an hvac company first, which I suspect will send me straight back to the diy option. That's how pretty much all of my projects go, and the reason I get further and further behind every year.
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I grew up in an non air conditioned room over a garage like you're describing. You know how I turned out. Proceed with caution.
 
Very happy with the 18k BTU Mr. Cool that I installed in my garage. Super easy to install, works great.
 
I installed one in the area over our garage. It was unfinished space that I built out. Ours works well for that space, but the thermostat for it is proprietary. That is unfortunate as I like the internet connected Honeywell thermostats.
 
Spent the day spec'ing out my house system. Need 3 zones, two 7k btu, one 9k btu. I figure a 3 zone 27k btu outside unit. Senville looks to be the best price all in, but don't know if they mix and match wall units and line kits. One 15', one 25' and one 50' line run. Looks to be about $3,500 all in for DIY. Warrantee looks reasonable. Still need to sharpen the pencil on pricing.

Worth every penny if it's quiet.
 
They are quiet....and you'll love the electric bill.

Just make sure you put at least 300 psi in the lines overnight....to check for leaks. It should hold that. Once it holds you're good to go to pull a vacuum and release the kracken. :D
 
Chip Sylverne said:
Spent the day spec'ing out my house system. Need 3 zones, two 7k btu, one 9k btu. I figure a 3 zone 27k btu outside unit. Senville looks to be the best price all in, but don't know if they mix and match wall units and line kits. One 15', one 25' and one 50' line run. Looks to be about $3,500 all in for DIY. Warrantee looks reasonable. Still need to sharpen the pencil on pricing.

Worth every penny if it's quiet.
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You can mix and match linesets, but those BTUs are really low. Small and efficient house? As a comparison, my 1950's era house with open floor area is about 900 sq with a big picture window, and 9+15K BTU cannot keep up. The outside unit can be about 70% of the total of the wall units but it'd be better to match them as the price difference will likely be small.

@Jim K Are there IL or Fed tax credits? Pretty sure Fed is a yes around 25-35%, but checking to see if you found them yet.
 
All mini splits I’ve seen are very quiet. Usually they don’t run on max unless they’re significantly undersized or if (like me) you make big temperature changes. In the shop I’ll keep the normal temperature at 50 during the winter and 80 during the summer, and then change it when I go in. Even on max, they’re quieter than my standard home split systems.

I wish they made mini splits that were bolt in replacements for RV rooftop air units, especially for low temp operations.
 
masloki said:
You can mix and match linesets, but those BTUs are really low. Small and efficient house? As a comparison, my 1950's era house with open floor area is about 900 sq with a big picture window, and 9+15K BTU cannot keep up. The outside unit can be about 70% of the total of the wall units but it'd be better to match them as the price difference will likely be small.

@Jim K Are there IL or Fed tax credits? Pretty sure Fed is a yes around 25-35%, but checking to see if you found them yet.
Click to expand...

Pretty small. All brick single floor early 60's construction. 1350 ft2, divided into two 300 ft2 bed, bath and dressing combo on one table end, an office the opposite end with a garage on the far wall, the remainder being LR, dining area and kitchen open plan in between. Just me and the wife. Cellulose blown in all the walls, and fiberglass batting in the attic. One big picture window, facing south but shaded by a covered front porch, and one double French door on the north under a wide soffit. Storms on all the windows. The gable end western exposure is only 26' and two windows. We have a boiler, but this winter we heated with a small wood stove in the fireplace with boiler as supplement. Used very little heating oil, maybe 50 gal Oct to March, though it was a pretty mild winter. Domestic hot water off the boiler. Small, tight and efficient.

I figure one 7k each in bed and office, and a 9k in the "big room". Might be a little undersize, but I hear that's better than oversize to keep the humidity down. Looking at 2 16" ceiling cassettes and one wall unit. The outside unit will go on the NW corner where the current condenser is and has power and disconnect. Wall unit there, and line sets to the ceiling cassettes through the attic. May have to up the btu's for that reason, can't seem to find ceiling cassettes under 12k. The current 3 ton central air jet engine keeps up, but barely on a stretch of 95 degree days. But it's old with mismatched condenser and evaporator.

Could actually put a small, separate unit in the office as power has been run there for electric baseboard that could be re-purposed, and avoid a long line set run, but it's the front of the house and...well, ugly.

No orders have been placed yet, still deciphering, so suggestions are welcome!
 
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