Navigating Minisplit Waters - Help, Please

[paulsomlo]

I know there are dozens and dozens of threads regarding ductless mini's, but I'm hoping that some of you will take pity on me and spare me the two hours of reading.

I have three areas in my home that need heating/cooling; first question - should I go with a DIY like Mr. Cool, or is the price differential between a DIY and non DIY enough to pay for the vacuum pump and gauge set?

Also, should I go multizone or 3 separate outdoor units? Two of the zones will be in close proximity to each other. If I go multizone, and the outdoor unit fails, I lose heat in both zones.

Should I go bundled, or choose separate indoor and outdoor units?

If an indoor or outdoor unit fails, can I just replace one, rather than a whole system? I'm assuming that I would have to stay with the original manufacturer, for compatibility.

I've looked at numerous websites selling these things, but I'm still baffled as to all the choices.

 

[shade]

I have 4 Mr Cools deployed in severe environments and they have worked great.
I dont like a single point of failure so my opinion would be use multiple units vs multiple zone units. If an indoor coil fails, you can get a new one vs an entire unit. They just need to match to spec.
I just bought 2 more Mr Cools on Cosctos site for much cheaper than any online retailer could come close.
It was $2200 for a Gen 5 24k unit. Closest I could find was Ingrams at $3k. Hope this helps

 

[pcmeiners]

Really you need to spend a couple hours going through the threads concerning minisplits.

A pointer.....
Your live in an area which requires a lot of heating so the HSPF number ( Heating Seasonal Performance Factor) is far more important than the SEER number in regions requiring heat; heating costs up to 4 times the cost of cooling. You could have a great SEER and a rather poor HSPF in a mini split. Basically if you want a high HSPF you will pay more for a mini split up front but recupe in long term savings and comfort.

Single zone mini splits are more efficient than multi zone units by far. They also provide redundancy. Between my home and garage I have (5) single zone mini splits.


As to rough tools cost, but the sky is the limit on HVAC tools.....

Nitrogen tank, cost varies, you can lease or buy. $150
Regulator, capable of 600psi , Ebay $75 buy new
Micron gauge $200 buy only new, first two I purchased new leaked, be careful.
Vacuum pump $200, used is OK sometimes, Ebay, FB
Flare tool $75
Manifold $200
Valve core remover $50
Refrigeration Recovery machine $300 used, Ebay or FB, worth buying if you have multiple minisplits. If you get this you need a scale and recovery tank(s).
Scale $100
Recovery tank $75 for a non DOT tank
Miscellaneous hardware $200, valves, connectors , hoses, filters, driers.

With multiple minisplits it paid for me to get all the above

"If an indoor or outdoor unit fails, can I just replace one, rather than a whole system? I'm assuming that I would have to stay with the original manufacturer, for compatibility."

If an indoor or out door unit fails, you will likely find it pays to get a totally new unit. Generally the warranties are useless with stipulations. Have (5) units, with a 608 cert I was able to get warranties on all 5. With the redundancy provided by my single zone units,(same manufacturer/same series) having warranties may pay off for me. if a single unit, or multiple brands are used many warranties are useless.

"Should I go bundled, or choose separate indoor and outdoor units?"

Basically you do not have much of a choice, the indoor/outdoor unit packages are designed/engineered to work together. If you had HVAC knowledge you could play with hardware matches, you do not have the knowledge.

 

[rattle_snake]

All A/C systems can be DIY. No need for scam artist (HVAC thieves).

If the lineset length needed is what comes in the box, no need for more juice. Just adapters, manifold/gauges, vac pump and done. Same stuff for a car A/C. If longer lines, you need to acquire and add refer. When it comes back cold, your done.

I would do separate outdoor units. probably cheaper and redundancy.

 

[jkeyser14]

I

I know there are dozens and dozens of threads regarding ductless mini's, but I'm hoping that some of you will take pity on me and spare me the two hours of reading.

I have three areas in my home that need heating/cooling; first question - should I go with a DIY like Mr. Cool, or is the price differential between a DIY and non DIY enough to pay for the vacuum pump and gauge set?

Also, should I go multizone or 3 separate outdoor units? Two of the zones will be in close proximity to each other. If I go multizone, and the outdoor unit fails, I lose heat in both zones.

Should I go bundled, or choose separate indoor and outdoor units?

If an indoor or outdoor unit fails, can I just replace one, rather than a whole system? I'm assuming that I would have to stay with the original manufacturer, for compatibility.

I've looked at numerous websites selling these things, but I'm still baffled as to all the choices.

I am dealing with a failed multizone system right this moment. If you spring a leak in any component in any zone the entire thing goes down. Then you are stuck replace the outdoor unit and all indoor units anyway due to obscolence, refrigerant differences, etc. Also, you can't have one zone in heating and one in cooling, they all have to be in the same mode which ***** for shoulder seasons.

I am replacing my multi-zone with two independent systems.

 

[pcmeiners]

I would do separate outdoor units. probably cheaper and redundancy.

More expensive but having redundancy is worth it. With single zones no emergency repairs, repairs can wait, your not forced to pay emergency repair rates. With multiple single zone units I can wait until the weather is better for a DIY repair. For non DIY, no absolute emergency, you can get multiple quotes for a repair while still having heat/cooling from the other units.

 

[dcg9381]

I have three areas in my home that need heating/cooling; first question - should I go with a DIY like Mr. Cool, or is the price differential between a DIY and non DIY enough to pay for the vacuum pump and gauge set?

IMHO, you're paying for a "consumer warranty" and Mr. Cool's increased support costs. It's not necessarily a better unit (construction wise). But end-consumer support and warranty are possible. Most all other units that I know about you absolutely can DIY install, but no warranty unless you hire someone with a license (and perhaps a relationship with the brand).

Also, should I go multizone or 3 separate outdoor units? Two of the zones will be in close proximity to each other. If I go multizone, and the outdoor unit fails, I lose heat in both zones.

I found that single units actually were less expensive than a multi-head unit.
Down side of multi-head is single point of failure.
Down side of single head is 3x points of failure.

If an indoor or outdoor unit fails, can I just replace one, rather than a whole system? I'm assuming that I would have to stay with the original manufacturer, for compatibility.

Depends. The tech changes and replacement parts are much more specific. Refrigerant requirements can also change and pretty much doom HVAC including traditional. Eventually you'll be replacing the whole thing. They have less "longevity" over traditional HVAC systems.

Pay attention to what @pcmeiners said. The heating capacity and heating efficiency is very important, especially in cold climates.

 

[fitter30]

I'm very rural install Two 3 head units in my house. Two units zoned and if there's a problem with one system have heat or cooling. Parts for minis are probably a minimum one plus day away or could be week. Need to look at you tube for how to clean a wall unit. Being in Colorado need a unit that can heat below 0° Hyper heat. Check with the different manufacturers for btu output in your coldest weather and temperature that is the cut off temperature.

 

[pcmeiners]

Agree you need low temperature units in your region but you will pay extra for it.

 

[dscheidt]

Agree you need low units in your region but you will pay extra for it.

the price difference is getting pretty small on a lot of units, especially if you're not buying one of the big name brands.

 

[pembol]

Also in Colorado here - in our climate the heating performance is FAR more important than cooling performance. Comparing the heating performance of the Mr Cool units with pre-charged line sets to other 'hyper heat' units that require a vacuum pump/guage set makes it pretty clear you don't want the Mr Cool pre-charged option for heating in a colder climate.

Efficiency, turn down ratios and redundancy are better with single head units, for your situation I would want at least two systems, if not three. The Gree Saphire /S5 units have really good cold climate heating performance at not a huge premium over the MrCool so they would be a good benchmark to compare to.

 

[jblnut]

I just had a pair of Fujitsu units installed in my shop. A 24k and a 9k. Both separate systems. After the tax rebate and rebates from the power company I’ll be into them for $4200. Factor in that they’re a business expense and I can expense the entire purchase price and it’ll be a final out of pocket under $2k installed by a “scam HVAC” company that’s been around for 4 generations and still a small mom and pop shop that is busy busy busy but always makes deadlines and is fair on pricing.

I’d look into hiring it out first to see what you’re up against before deciding to DIY it. I’d have been more $$ into a DIY setup personally.

 

[KenC]

I just installed a new 18K Pioneer low ambient model. It replaced a 7 year old Pioneer 12K unit that was/is still working perfectly, just undersized for my room addition. Now is a great time to buy as the 410A units are being priced to move. Mine cost less than $1100 shipped.
Took me about 3 hours to install as the wall was already prepared as was the power.
I did not do a nitrogen pressure test. Really should I guess but this is my 3rd Mini install and so far I've had no refrigerant loss. Just make good flares, use Nylog or similar and be sure to align and tighten correctly.
Obviously, I do have flare tools and a good vacuum pump.

I'll be selling my 12k that I took out and was able to pump/capture all the refrigerant in the condenser so the buyer will be able to install it just like a new unit.

I chose Pioneer because of the customer service experienced on the first one. The indoor blower motor failed during the first week, I contacted them and a new motor was shipped the next day. No hassle about owner install as they provide a 12mo warranty for owner installed units, parts are in stock, and if you have a pro install done, then register it there is a 5 year warranty.

On the other hand, my first mini was a name brand, LG. Never again. No parts support, the local dealer didn't even know that they had
the Phone app and adapter needed to do most anything to troubleshoot it. I had to order a thermistor. Took over two months to get it. Removed, replaced with a Pioneer and never will buy another LG anything.

And don't even ask about the refrigerator.

Edit: I forgot to mention that the Pioneer manuals are very good and it's obvious they were tailored for DIY installs even though they don't explicitly say so.

 

[paulsomlo]

Thank you all for your replies - two things jump out; single zone is preferable over multizone and given my locale, HSPF will figure prominently.

I should have given more info about my use case - I've got a small workshop that's about 200 sf of brick wall with insulation only in the ceiling. It now has radiant electric heat and no AC, expensive to heat ($3-4/day) and too hot in the late summer afternoon. The room I'm sitting in has no heating or cooling as it has no ductwork - it was originally garage space; I removed a gas wall heater many years ago and the room depends on the ducted GFA from the rest of the house. My 50 year old AC hasn't worked in at least a decade, so I'd like a minisplit in the largest room on the main floor. Really, I'd like to get away from my GFA furnace, which is 50 years old and located in the crawlspace. Every time I have to go down there for maintenance, I curse this house - I've nicknamed the filthy dusty crawlspace, "The Devil's Bottom". I'd like not to have to ever go into the crawlspace again, don't know if that's realistic or not.

The one thing I didn't ask about, is refrigerant - should I be concerned about 410A and obsolescence? Should I be looking at units with R-32 or R454?

 

[jkeyser14]

I would avoid R410A because the phase out. R32 or R454B are a coin toss. R32 is readily available now but only really used by Daikin systems, everyone else is moving to R454b which is stupid expensive and in a global shortage. However, R32 is scheduled to phase out in several years...

 

[txvwnut]

Don't avoid a unit because of the refrigerant. The current phase out is for manufacturers and not the repair side of the industry. It will likely be 10 to 20 years before the current refrigerant flavor of the day is completely gone.

 

[chrispyny]

I just installed a new 18K Pioneer low ambient model. It replaced a 7 year old Pioneer 12K unit that was/is still working perfectly, just undersized for my room addition. Now is a great time to buy as the 410A units are being priced to move. Mine cost less than $1100 shipped.
Took me about 3 hours to install as the wall was already prepared as was the power.
I did not do a nitrogen pressure test. Really should I guess but this is my 3rd Mini install and so far I've had no refrigerant loss. Just make good flares, use Nylog or similar and be sure to align and tighten correctly.
Obviously, I do have flare tools and a good vacuum pump.

I'll be selling my 12k that I took out and was able to pump/capture all the refrigerant in the condenser so the buyer will be able to install it just like a new unit.

I chose Pioneer because of the customer service experienced on the first one. The indoor blower motor failed during the first week, I contacted them and a new motor was shipped the next day. No hassle about owner install as they provide a 12mo warranty for owner installed units, parts are in stock, and if you have a pro install done, then register it there is a 5 year warranty.

On the other hand, my first mini was a name brand, LG. Never again. No parts support, the local dealer didn't even know that they had
the Phone app and adapter needed to do most anything to troubleshoot it. I had to order a thermistor. Took over two months to get it. Removed, replaced with a Pioneer and never will buy another LG anything.

And don't even ask about the refrigerator.

Edit: I forgot to mention that the Pioneer manuals are very good and it's obvious they were tailored for DIY installs even though they don't explicitly say so.

i can’t find any remaining 410a units on any sites. Seems like they are sold out? Where did you get yours?

 

[KenC]

Pioneer store online. Pioneerminisplit.com Don't know if they are sold out but that's my source. https://www.pioneerminisplit.com/collections/r410a-final-stocked-systems

 

[paulsomlo]

So, what's a reputable online retailer for Fujitsu or Daikin?

 

[Yankeefarmer]

Ingram’s Water and Air iwae.com sells Daikin.

 

[dcg9381]

So, what's a reputable online retailer for Fujitsu or Daikin?

I bought my Daikin from:

Daikin Air Conditioning & Heating Solutions

Discover Daikin’s advanced HVAC systems and components. Shop mini-splits, heat pumps, and more to elevate comfort and energy efficiency.

heatandcool.com

 

[Higgy1300]

i just finished up my install of a Tosott brand, had good reviews. i had the garage down to 76 degrees in about 2 hours. this is in Florida it was about 96 with heat index. i bought direct from them

 

[paulsomlo]

I've got a room that's 9'x21', 3 exterior walls; is it better to put the head unit on the long wall or the short one?

 

[Jackfre]

I would split the load up. Put a single in the primary area and a dual/tri for the balance. The singles are generally higher efficiency. When I last bought, the big step cost wise was fat the triple stage.

 

[dcg9381]

I've got a room that's 9'x21', 3 exterior walls; is it better to put the head unit on the long wall or the short one?

They're a bit directional, so whatever gets that air the the middle of the room best.. Room that small, probably won't matter.

 

[SVibs]

Most all other units that I know about you absolutely can DIY install, but no warranty unless you hire someone with a license (and perhaps a relationship with the brand).

That's not been my experience. I installed a Senville 24K unit in October 2023 and registered the unit to activate the warranty. They ask for the HVAC License #--I provided the EPA 608 Universal Certificate number and they approved the warranty registration. I had a condenser motherboard failure in July 2025 and support was very helpful and sent indoor and outdoor unit motherboards under warranty. They were very helpful over the phone, no hassles, no questions about whether I was qualified to do the work. Parts come from Canada and it took 5 days from initial call to parts in-hand. I also had a number of pre-sales questions and found them very responsive and helpful.