# Your experience (good or bad) with mini splits for the shop



## B4B (Sep 6, 2014)

Folks,

I'm now working out of a 2 car attached garage (whowhoo). I am in the west Virginia panhandle so cold winters and hot humid summers. I'm looking at installing a ductless mini split heat pump.

Are there folks here who have these and can share their failures or successes with them? What brand did you install?

I'm primarily looking to diy the install to save the cost of an hvac contractor effectively double the cost of the unit. I've seen pioneer and mr cool units have diy specific options, and there are a few other brands out there. At about $1,300 plus some sweat i figure its worth it over a window ac and continuing to use a propane cabin heater.

Any folks here who have these and can share their failures, lessons, or successes with them? What brand did you install and is it standing up to the test of time? Is you diy or hire the install?


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## DavePolaschek (Oct 21, 2016)

I had one in my garage in MN, and got one when I built my shop here in NM. Mitsubishi installed by pros in both cases. They're wonderful, and the only caveat I'm aware of it that you have to climb up and clean the sawdust out of the filter periodically. Like once or twice a year in my mostly hand-tool shop.

Installation in the garage in MN was a year after the garage was built, and was no big deal. Here in NM installation was part of the build. In both cases it was relatively easy, with the condensation drain tube being the biggest challenge (remember that it has to flow downhill). But I also prefer to pay people for stuff like that and spend my time doing stuff I like, rather than drilling holes in stucco and then patching the mess when I screw up.

My sweetie has been impressed enough with the mini-split and the low cost of operation that we're going to get two put into our house to replace the (loud and dirty) swamp cooler this spring.


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## wapakfred (Jul 29, 2011)

I'll be interested in the replies you get, in my case Ive already decided to get one for my shop. I'm heated with a ceiling type LP gas furnace, so my interest in them is the cooling part for the summer. Of course I'd also use it for heat…but that's secondary to me. Right now I have a window unit for AC, but it's expensive to run. Everything I've read about the mini splits make them perfect, except for the up front cost.


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## bigJohninvegas (May 25, 2014)

I have a Mr Cool DIY mini split in my shop and love it. 
Here is a link to my review. I just gave it another update. So check it out. 
https://www.lumberjocks.com/reviews/12014

If you go with the DIY system. Consider this, you see I have the conduit covering the line set. I don't remember the brand name. It's not Mr Cool. But I did mail order from Home Depot at same time I ordered the Mr Cool system. 
I ran the electrical all inside. And a just this year had the main HVAC on the house replaced. That pro HVAC tech liked my work. And has a much better conduit that I can buy. 
I have not done that yet. 
But he also showed me that I could have rubn the line set indoor as well. Same 3.5" hole, but would have came out right next to electrical run. And no conduit on the side of my house. Would have been much cleaner looking. If I ever have to disconnect the line set, I will run it that way then. About the only way it will ever happen is if I have to replace the system some day.


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## ibewjon (Oct 2, 2010)

I have an LG mini. VERY efficient. 28 seer. I can cool my 16×20 shop for 25 cents a day. And it will work as a heat pump down to minus 14 if I remember correctly. I kept my 4 kw in wall heater for backup heat if ever needed. Just keep the filter clean. And it needs to be sized correctly, NOT oversized. You will cool quickly but before the humidity is removed. A properly sized unit will not work for part time operation as it does take time to do its thing. A good dust collection system is important to any heat source. The outdoor unit must be above snow level to work. I put mine 2' above grade.


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## OSU55 (Dec 14, 2012)

The only cons are the expense, the $, and the cost . Keep the filters clean! Leave dirty filters and you can kill a system.


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## theoldfart (Sep 9, 2011)

Same as you, two car garage shop. We had mini splits by Mitsubishi back in Massachusetts and they worked well. They work extremely well here in Northern California, my shop is comfortable year round. and yes, clean the filters regularly.


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## Smirak (Dec 24, 2016)

I'd be interested in replies as well. I just built and had 220 run on the outside wall specifically for a mini split. However, I didn't take into account the size and think that the "smallest" 220 unit is oversized, so I'm now looking at a 110 unit for my shop which is about 220sq ft


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## EarlS (Dec 21, 2011)

I have a mini split - Ameristar that was installed when the house was built (shop was finished with insulation and drywall at the same time). It has a heat pump which helps keep the electrical costs down. It does a decent job both heating and cooling. I just have to remember to clean things out periodically. It's been installed for a bit more than a year. The A/C condenser is located outside.

All in all, I'm happy with it. It is a lot less hassle than a dedicated 220V heater and a window A/C unit like I had in my old shop.


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## brtech (May 26, 2010)

I don't have a mini-split in my shop, but I do have one in my home office. The original one was a Bryant labeled unit which was actually a Carrier product. It didn't work = could not maintain a comfortable temperature when outside temps were at their extremes (-5 to +95 here in Western PA). It was chosen and installed by the contractor who did the reno that created the home office.

In talking to my regular HVAC guy, who is a Carrier distributor, he indicated that he refuses to sell those units. He replaced the Bryant with a Fujitsu unit with very similar specs. It works very well, I'm very happy with it.

So brand seems to matter quite a bit.


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## Peteybadboy (Jan 23, 2013)

I have had one in my shop for quite a few years now. Its so hot in s/w fla that it really can't cool down the shop. I also think it needs to be serviced. BTW you do get a lot of saw dust in these things!


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## ibewjon (Oct 2, 2010)

If it won't cool the shop, I would say it was not sized correctly or you lack insulation. A rough figure is 600 square feet per ton of AC.


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## Jake229 (Jan 14, 2020)

I opted for a Mr Cool DIY to cool my shop. I put in an overhead natural gas heater for heat. The mini split is fantastically efficient for cooling. Heating….... not so much. Additionally, it only heats to 5 degrees. So far, it's been fantastic. Kept my shop cool while I was installing the metal ceiling and it worked well. Haven't had an opportunity to use it with the ceiling in and attic insulation in. I expect it will work well.


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## bigJohninvegas (May 25, 2014)

> The only cons are the expense, the $, and the cost . Keep the filters clean! Leave dirty filters and you can kill a system.
> 
> - OSU55


Expense was shocking to me. I had 3 pro HVAC quotes. And all were around 6k. 
My 24k BTU Mr Cool unit cost me right at $2200. That was the unit, all the electrical to run 220v, and the conduit for the line set. 
It was very risky for me, as most all the reviews I read were people that used it primarily for heat. And here in the Las Vegas desert I am primarily 
using A/C. Actually had no intention of using heat. But now I am running it pretty much all winter too.

It works better than I could have ever expected. And I should add that my garage/shop is very well insulated to start with.

So now just this last year. We have had to replace 3 HVAC systems at work. Smaller structures, control rooms for crushers, and a Asphalt plant. 1 window unit, and 2 smaller very old central A/C systems. 
All were replaced with Mini Splits. They are all Lenox systems,, And I was surprised that they look exactly like the Mr Cool Brand. Even the remote. 
So not sure if Lenox makes them, or a parent company. But the are exact matches.


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## B4B (Sep 6, 2014)

Thanks everyone for the insight and feedback. I'm convinced now that the mini-split is the way to go. I just need to figure out what size unit and run calculations.

bigJohninvegas I saw your review when I was poking around for information, thanks for keeping it up to date. It's really helpful when I find folks like you who review things and update it periodically.

For anyone looking, Costco sells the Mr Cool DIY, the 12000 BTU unit is currently member priced at 1099 plus tax to the door. That's about $300-500 less than most other suppliers I've seen online.


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## ibewjon (Oct 2, 2010)

I found an AC contractor that would run the line set and allow me to install both indoor and outdoor units and run the electrical. Saved a lot of money. I purchased the LG mini, which was super efficient from Supply House.com. They have great customer service. And no, I have no ties to the company, and get no incentives to mention the name. As I said earlier, the unit I chose is able to heat efficiently to temps below zero. I have an hour meter and kilowatt hour meter on the unit to see the actual power usage. Not all mini splits have the same efficiency rating. The more efficient units will have a higher initial cost, but can be well worth the extra upfront investment.


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## Lazyman (Aug 8, 2014)

> For anyone looking, Costco sells the Mr Cool DIY, the 12000 BTU unit is currently member priced at 1099 plus tax to the door. That s about $300-500 less than most other suppliers I ve seen online.
> 
> - B4B


Is that the 115V or 230V unit? Home Depot has a 230V unit for $746.


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## B4B (Sep 6, 2014)

> For anyone looking, Costco sells the Mr Cool DIY, the 12000 BTU unit is currently member priced at 1099 plus tax to the door. That s about $300-500 less than most other suppliers I ve seen online.
> 
> - B4B
> 
> ...


Mr. Cool has at least two lone, the DIY line and the Advantage line. That is the "advantage" line and its 19 seer vs 22 seer for diy, and its meant for "pro install" as the lines need to be vacuumed first. The DIY come with vacuumed or pre-charged lines. The advantage is installable by a dryer but it does require some specialty tools a dryer wouldn't have on hand.. they are moderately priced tools. The DIY line can be installed without specialty, tools most homeowners probably have on hand.


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## dbw (Dec 2, 2013)

I purchased a Pioneer 1.5 ton at Home Depot for $1200. I paid an AC pro $500 to install it and I paid an electrician $150 to run the power. I am fully aware of my limitations. Cutting holes in brick is not my forte. Neither is installing/evacuating/charging an air conditioner. As a point of reference I got 2 bids for "turnkey" jobs. One company wanted $4000 and another wanted $6000. Their brand was Mitsubishi. There was no way I was willing to spend this kind of $ on a mini-split which I will be using on weekends.

As far as performance is concerned this unit is working perfectly. I have it set to 70F and it just hums right along.

As far as I'm concerned the $ I spent on having a pro install it is priceless. If I had screwed it up it would have cost me more than $750 to fix it. Not to mention the time required to mess with it.


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## bmerrill (Mar 14, 2018)

Semi self installed a Mitsubishi MSZ/MUZ-GL24NA system in a 24×24 garage, 12' ceilings, walls and garage door (7×18) are all insulated, located in eastern North Carolina. Only use when needed. It works better than expected. 
Have to clean the filter regularly as mentioned above. Since it's not running all of the time, it does take a while to heat the room and the contents, as well as to cool. Once it has, recovery is quick after the door is opened/closed. 
Mitsubishi does require a licensed HVAC contractor to install (connect line set, pull vacuum, charge the system) if you want the system warrantied. Haven't noticed any difference in the elect bill.


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## Baddad84 (Dec 26, 2015)

So why are people running the split unit instead of an a package unit where all equipment is outside?


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## dbw (Dec 2, 2013)

> So why are people running the split unit instead of an a package unit where all equipment is outside?
> 
> - Baddad84


A ductless mini split is way less complicated. It doesn't require a plenum or ducts. Hence the term "ductless". The ductless systems still have an outside unit and an inside unit.


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## Woodmaster1 (Apr 26, 2011)

I have the old fashion mini split. A bigmaxx 50000 btu gas furnace and 10000 btu window air. The furnace cost $120 to run at 70degrees during a northern Indiana winter an the air I am not sure how much it cost because the pool heater is on the same meter as the garage.


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## ibewjon (Oct 2, 2010)

Old fashioned and way less efficient. Window air conditioners are energy hogs.


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## wapakfred (Jul 29, 2011)

> Old fashioned and way less efficient. Window air conditioners are energy hogs.
> 
> - ibewjon


Exactly why I have an interest in the mini split.


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## surrywood (Aug 24, 2017)

This thread is really timely for me as well, I am planning to install one in the spring, and I will want both heat and AC. I have a 22×24 (528 sq ft) 2-door garage shop I have been using for almost 2 years and I just installed door insulation panels last week. The whole thing is insulated up to the 8ft ceiling line but above that it is not insulated and it is virtually open air up there in the rafter zone, so it is mostly open up to the 24-28ft apex of the building. I do not have the inclination to get up there and try to insulate the underside of the roof and out here where I live, bringing in pros to do work is cost prohibitive on most things.

My question is, do any of you have a similar situation, and if so, does the unit perform to satisfaction? I will likely not put ceiling panels of any kind in because I need the joist space up there for storage and I need to be able to access it via folding ladder


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## Lazyman (Aug 8, 2014)

Insulation is pretty important. About half of the walls are uninsulated exterior walls and half of the ceiling of my garage shop were not insulated. In the summer, the ceiling sheet rock would measure about 120° so I cut an access hole to crawl up there and rolled out some insulation. Now the ceiling temp is in the 90s on even the hottest days. I can definitely tell the difference. I didn't realize how much of the heat I was feeling was actually heat radiating from the ceiling. About half of the walls are still not insulated and it would be expensive to do because they too have sheet rock. I insulated the metal door a long time ago and that definitely makes a huge difference but another thing that made a huge difference, especially in the winter, was putting a weather strip around the top and sides of the garage door. Just keeping the air from leaking around the door keeps the cold and hot winds from leaking into my shop. IMO, the insulation and the weather strip will pay for itself, especially if you can do it yourself.

EDIT: One more thing that I just did recently was put some patio solar shades over the garage door. My door faces west and in the afternoon, the sun heats the door to about 140°. While the insulation keeps the worst of the heat from penetrating, the exposed metal frame is still very hot and heat still gets in. The solar shade dropped the temperature of the exposed parts of the metal door so that they don't get above the ambient outdoor air temperature now. I mostly added the shade to block the afternoon sun and glare when the outside temperature is nice enough to work with the garage door open but I leave it down even when the door is closed to further reduce the heat transference affect of the metal door.


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## theoldfart (Sep 9, 2011)

Nathan, I think I'll try that shade idea. Ceiling insulation gives the best bang for the buck for me, next was the door insulation.


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## Lazyman (Aug 8, 2014)

I was originally going to get a SunSetter Awning so that I could also do some metal working in the shade on my driveway but decided that this was a cheaper alternative that I would not have to worry about when storms blow through. I have 2 awnings so that I can raise one up when I am going in and out of the shop.


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## bigJohninvegas (May 25, 2014)

> I found an AC contractor that would run the line set and allow me to install both indoor and outdoor units and run the electrical. Saved a lot of money.
> - ibewjon


That's Great, After getting quotes at 6k to install a mini split I looked to do just what you did. Several months later I could not get a HVAC guy to run a line set and charge a system that I installed. I felt it was just greed on there part. 
That's when I went ahead with the Mr Cool. I had a pro basically gave me a shopping list of all the electrical I needed. Got it all run, then he came over and installed the breaker, checked my work to make sure I did what he told me. Pretty easy actually. 
I had the main HVAC replaced on my house last February. that contractor looked at my work, and said it was good but, I should have put the breaker or a disconnect at the condenser unit. Where I only have a breaker in the main panel. He also said he would have done the job for about $3500, vs the 6k quotes i got back in 2018.



> This thread is really timely for me as well, I am planning to install one in the spring, and I will want both heat and AC. I have a 22×24 (528 sq ft) 2-door garage shop I have been using for almost 2 years and I just installed door insulation panels last week. The whole thing is insulated up to the 8ft ceiling line but above that it is not insulated and it is virtually open air up there in the rafter zone, so it is mostly open up to the 24-28ft apex of the building. I do not have the inclination to get up there and try to insulate the underside of the roof and out here where I live, bringing in pros to do work is cost prohibitive on most things.
> 
> My question is, do any of you have a similar situation, and if so, does the unit perform to satisfaction? I will likely not put ceiling panels of any kind in because I need the joist space up there for storage and I need to be able to access it via folding ladder
> 
> - surrywood


So insulation is everything. I think you are going to be very disappointed with the performance with out it. 
I do have a fully finished insulated space, and would love the open rafters you have. But that is extra space to heat and cool, so make sure to calculate that. HVAC is not about square footage, but cubic area to be heated/cooled. 
With the open ceiling, and not wanting to hang sheet rock, I would look into adding insulation up at the roof itself. that's not ideal, No cold zone, but would be affective, and better than nothing. 
I remember dad had a one car metal garage. DIY shed style kit we built one weekend some 40 years ago. Nice roll up door though, and much heavier metal than the typical shed. 
He used 2" styrofoam panels, liquid nailed to the ceiling and walls. And a little window unit. Did alright for him. 
In your case spray foam, or fiberglass batting. 28' is up there, but you won't regret doing it.


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## ibewjon (Oct 2, 2010)

Code requires a disconnect at the outdoor unit, mini split or standard. It can be a non fused properly rated switch. It is for the safety of the service person.


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## Knockonit (Nov 5, 2017)

I was planning on a roof mounted, 2.5 ton heat pump for my new 1k sq ft shop, but as of friday discussing with a supplier opted to go with a mini split, i am doing a 3 zone, as i have an approximately 200 sq ft area to be a clean zone so to speak.

here in Phoenix, i find i will only use it a few months out of the year, i did put in a whole house type fan, and do have ground cooler for the outside work when welding ect.

should have roof on unit by mid january, as i'm doing a lot myself, taking me forever it seems like, 
just finished filling tooled exp. jts, with a silica and epoxy based filler, and have it almost ground down, as i want a seamless floor, once roof is on, i'm a gonna epoxy floor, rollup door due end of next week, so….....it will be enclosed by end of month. 
oh yeah Foam at underside of roof ply, i want open trusses, 
happy sunday
Rj in az


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## sansoo22 (May 7, 2019)

> That's Great, After getting quotes at 6k to install a mini split I looked to do just what you did. Several months later I could not get a HVAC guy to run a line set and charge a system that I installed. I felt it was just greed on there part.
> 
> - bigJohninvegas


This has been the issue I'm running into. My cousin is a HVAC tech. Fully licensed, bonded, and insured…just not in my state. I live right across the state line and he lives in a small town about 2 hrs away. He would be more than happy to come visit for a weekend and help me with the install. They don't get to the big city often so he and the wife could come up, let the girls shop or whatever, while we install a mini split.

The problem is finding a local company willing to do part of the job. Or whatever part they need to actually "sign off" on it so it passes code/inspection. I wouldn't care if they charged me $1000 to come hook up power, vacuum/charge the system and turn it on the first time. That's a decent profit for like 2 hours worth of work. It seems they either want to do the whole job for 5 to 6k or not make any money at all. If its an insurance thing for them they need to say so otherwise it just feels like greed.

Technically I don't need an HVAC company since my cousin could do the whole thing but in my city I'm told if we don't have it inspected and it ever malfunctioned and burned the house down I could end up with my home owners refusing to pay. Maybe that's why the local HVAC companies feel they should do the whole job or nothing.


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## MadMark (Jun 3, 2014)

You can't warranty what you didn't install. Since the parts interact and improper installation can cause issues later, would *you* warranty everything when you only did part of the job.

Paying a pro buys you a # to call if it ain't right.

I was in IT until I retired but I buy computers instead of building them to avoid any and all issues with 'em and to have someone I can jack up if there is any issue.

Here in Fl AC is a must. Spring 2020 our AC started sputtering. Local co. replaced the whole house system for $6k - financed. Two man crew did it in under a day and left a spotless job. Been running at 70°F ever since without a burp. Electric bill is down $50+/mo even in the hottest months.


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## B4B (Sep 6, 2014)

Blown in insulation is inexpensive compared to batt and easy to install. Such it up, do the work once, and reep the reward.


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## surrywood (Aug 24, 2017)

Thanks all, I know I jumped in the middle of the thread with my own questions, my apologies for that, I thought they might be relevant to the overall. I do appreciate the responses and the knowledge bank on this forum.


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## ibewjon (Oct 2, 2010)

The insulation is not important if you have an unlimited wallet. You just need a bigger unit to cool the larger space. Money spent for insulation will be returned with energy savings.


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