Anyone running a mini split in their shop?

[HITCH-]

Hi,
Is anyone running a mini split in their shop?

I have a 400 sq. ft. garage shop attached to the house. First I was looking at portable air conditioner units. One of those would cost almost $600. That seems really steep for what it is. It looks like an 18,000 btu mini split that will cool and heat will run about $1,000. It seems like a no brainer for the cost difference.
Then I started to look at DIY installation. I am comfortable pouring the pad, running the dedicated circuit, hanging the unit and pulling the lines. What I am not comfortable with, nor do I have the equipment for, is the pressure test and final connections.
I looked online and "average" installation runs about 3K. I assume that to be for everything from start to finish.

For those of you who have one are you happy with the performance? Did you do the installation yourself and have any suggestions?

Thanks

 

[DSWalker]

I have a Pioneer 18k unit that heats about 525 sq ft. Install is pretty easy,though I did have a guy help with electrical install and final HVAC connection. He was there making all the breaker box connections for me for the shop. I paid him (retired guy) $1100 for everything he did in less than 2 days.

$3k seems pretty steep for install only.

 

[HITCH-]

Yeah I think that installs requiring multiple zones and such might raise the installation average cost.

David did he do a pressure test on yours first?
I read that it is not required and some installers don't do it but it is often recommended by the mfg.

 

[DSWalker]

Yeah I think that installs requiring multiple zones and such might raise the installation average cost.

David did he do a pressure test on yours first?
I read that it is not required and some installers don't do it but it is often recommended by the mfg.

It was 4 years ago, but I vaguely recall him running a pressure test. Can't recall exactly if it was before, after or both.

They are pretty much plug and play. If you have the tools to do the pressure test and make the copper connections it was a pretty easy setup. I didnt and hired a guy for the breaker box work that also could handle the HVAC connections.

 

[Rob in NC]

I looked briefly at a PTAC unit. Same type heat/AC units used in motel rooms. Seems would be perfect for a small shop and one can do a DIY install. This site lists new and refurb units.

Refurbished PTAC Units For Sale - 90-Day Warranty, Fast Shipping | PTAC4Less.com

We have wide variety of Refurbished PTAC Units for sale at great prices. Shop our online store for a full selection of products.

ptac4less.com

 

[JRedding]

I did a new shop build recently and had 2 Mitsubishi mini-splits put in as part of the build (shop is 1400 sf). I keep them on all the time and they are very efficient - energy bill is about $50/month (separate meter so know what they cost). I also like they have a dehumidifying function - it’s really just a stepped down A/C function, so doesn’t cool as fast and uses less electricity due to lower motor draw.

I had a ducted mini-split in my last shop and it also worked very well, which influenced my decision here. Overall very happy with the performance and way they maintain the atmosphere in the shop. We’ll see how well they do at keeping humidity down during summer later this year.

 

[rcarmac]

Check out this unit. https://mrcooldiy.com
I looked at this a few years ago but never purchased. They come with pressurized line sets. So no special tools or connections. That’s how they claim it’s completely DIY. The one down side, thru some with a set length of line sets. So you have to work with that length. No cutting it off if it’s too long and not adding length of it’s too short. Looked like a good system to me. That was the direction I was heading so I could do everything myself

 

[Trey1984]

The pressure test your talking about is pulling a vacuum on the lines. Pulled all the moisture and air out the lines before you release the from into the system. Mini splits come pre charged. The line also has to be flared just like lp gas copper gas lines. Other than those 2 things you could do everything yourself. They also require a separate fitting to check the freon in the system. It's smaller than a regular HVAC system hookup. All it is a adapter to hook up to regular freon gauges.

 

[Ted P]

I've had a mini-split for a couple years - wish I had done so sooner. I have a 750 sq ft shop with 12 foot ceilings and two insulated overhead doors. Mine is a one ton Hessaire that I installed myself. The mini-split keeps the temp 76 in summer and above 60 in winter. I purposely purchased smaller that I thought I would need as there is also a through the wall AC for peaking, but have not needed it. Smaller size running a lot does a better job of dehumidifying than a large unit running a short time.
I coiled the little bit of excess refrigerant line outside near the condenser as I did not want to re-flare the ends. I used the neighbor's vacuum pump to pull down for a couple hours before releasing the refrigerant, but had planned to buy one from Harbor Freight rather than pay an installation fee.
I had a circuit board failure a few months outside of the warranty period but they sent me a new one without charge anyway, only asking for the old one back. I did not go for the Mr. Cool because even though they are set up for homeowner installation as they say the warranty is not valid if not professionally installed - at least that was the case a couple years ago.

 

[Wilsoncb]

I installed mine and had a guy come out and do the final hook up (evacuation) for $150. I’ll send you a PM with his contact info as soon as I find his card. (I think he is near Whitsett.

I have a 24k unit for a 3 stall garage and it works very well. I really beats messing with propane heaters and fans that never really worked well.

Mr. Cool has a version with pre-charged lines, which would allow you to do everything without the need for a vacuum and gauges. However you are stuck with whatever line length they offer. You can coil the excess length, but I didn’t like that idea. In my case the Senville unit from Amazon plus’s the $150 for the hvac guy was still much less than the Mr. Cool at the time.

Also when looking at breaker and wire size, hvac units have ”Minimum Circuit Ampacity“ and “max. Fuse”. You can size to MCA. In my case it was a significant cost savings to be able to use 12 ga instead of 10 (for 75 ft).

 

[Westpacx3]

Hi,
Is anyone running a mini split in their shop?

I have a 400 sq. ft. garage shop attached to the house. First I was looking at portable air conditioner units. One of those would cost almost $600. That seems really steep for what it is. It looks like an 18,000 btu mini split that will cool and heat will run about $1,000. It seems like a no brainer for the cost difference.
Then I started to look at DIY installation. I am comfortable pouring the pad, running the dedicated circuit, hanging the unit and pulling the lines. What I am not comfortable with, nor do I have the equipment for, is the pressure test and final connections.
I looked online and "average" installation runs about 3K. I assume that to be for everything from start to finish.

For those of you who have one are you happy with the performance? Did you do the installation yourself and have any suggestions?

Thanks

I used an 18k Mr Cool DIY unit. Put it in with just and extra hand to lift it. I was out the door for about 1200 plus I went back fir the line set cover. My shop is 480 soft with 8ft walls but a cathedral ceiling that peaks at about 11 ft or so. Unit is 9ft off the floor at one end. It keeps the room nice except when we got into the below 30 digits. At that point I set it to about 75 degrees and used a fan to blow the air down. It would do fine in a garage. My build is off the ground on 6x6 posts so the lower few feet in the building was the only cold part. The walls are R18 and ceiling is R33. Floor is just tongue and groove 3/4 plywood with no insulation under it. The only real issue with the day is the prechsrged line set cones with a set length of line. I think 16ft or 25 ft. I looped the unused portion, strapped it to the wall outside and boxed it in. I also bought a scratch and ent model thwt saved me 500.00. Oh, I also needed to but the right size hole saw to drill through for the line set to go outside. About 37.00 or so

 

[jlwest]

I have a Daikin mini split in my 300 sq.ft shop. Self install was complicated because of block walls so I paid to have it installed and to get the 10 year warranty. Also needed permits for electric. I did add a secondary dust filter to help protect the heat exchanger.

 

[mikeh74]

I have a Mr. Cool 24k DIY mini split and have been very happy with it. The first one failed within a week but they have great customer service and replaced the unit. It's been running for almost tow years now with no issues.

 

[HITCH-]

The pressure test your talking about is pulling a vacuum on the lines. Pulled all the moisture and air out the lines before you release the from into the system. Mini splits come pre charged. The line also has to be flared just like lp gas copper gas lines. Other than those 2 things you could do everything yourself. They also require a separate fitting to check the freon in the system. It's smaller than a regular HVAC system hookup. All it is a adapter to hook up to regular freon gauges.

Actually what I was referring to was charging the lines with nitrogen prior to releasing the coolant. I have been watching YouTube videos and some installers do it and others don't. I guess I will see what the specific installation instructions are once I have picked a unit.

 

[ptt49er]

I installed a 18k Mr. Cool unit in our 600 sq ft bonus room over the shop last year. Installation was a breeze and it's worked fantastically. Can't wait to get my shop insulated enough to put down there.

 

[AllanD]

I just installed a 27K unit with 3 zones in a rental house last month. There are two basic types of installs, the MrCool is a total DIY with the refrigerant locked in the compressor and pre-charged lines that use quick connects. You will pay more for the equipment but have no additional labor charges. If the run to the compressor is shorter than the lines you will need to coil them up but be sure the coils lie horizontal so the oil will not get trapped.
The other type that I use has the charge in the compressor but not the lines. I cut the lines, flare, pressure test with nitrogen, vacuum decay test and then open the unit to allow refrigerant release. If you don't have the tools, nitrogen tank, pump, etc. then check around to get quotes from the pros to do that. The 3 zone unit was around 2200 from Lowes.
The best videos I have found are on Craig's youtube channel: acservicetech

 

[mike_wood]

Hi,
Is anyone running a mini split in their shop?

I have a 400 sq. ft. garage shop attached to the house. First I was looking at portable air conditioner units. One of those would cost almost $600. That seems really steep for what it is. It looks like an 18,000 btu mini split that will cool and heat will run about $1,000. It seems like a no brainer for the cost difference.
Then I started to look at DIY installation. I am comfortable pouring the pad, running the dedicated circuit, hanging the unit and pulling the lines. What I am not comfortable with, nor do I have the equipment for, is the pressure test and final connections.
I looked online and "average" installation runs about 3K. I assume that to be for everything from start to finish.

For those of you who have one are you happy with the performance? Did you do the installation yourself and have any suggestions?

Thanks

I have about the same size shop, 10' ceilings and an attic. I have a 12k Pioneer unit that works fine. Keeps the shop warm/cool and the attic is moderately warm/cool which is all I want. Right now I have thermo set at 63 and it is fine. You can save some bucks will a smaller unit.

 

[AllanD]

BTW Hitch, at first glance it seems that 18K BTU may be more than you need for 400 sq ft. Depends on how insulated and how leaky the garage doors are but if you oversize it too much it may run short cycles and not run long enough to dehumidify in the summer.

 

[HITCH-]

Yes, strangely enough 18k is what is recommended for a portable air conditioner but 12k is the recommended size for a mini split. I don't want it oversized.
What do you mean about running the coils horizontally? Maybe I am not understanding the terminology but I keep seeing them coiled vertically like these...

 

[Wilsoncb]

The other type that I use has the charge in the compressor but not the lines. I cut the lines, flare, pressure test with nitrogen, vacuum decay test and then open the unit to allow refrigerant release. If you don't have the tools, nitrogen tank, pump, etc. then check around to get quotes from the pros to do that. The 3 zone unit was around 2200 from Lowes.
The best videos I have found are on Craig's youtube channel: acservicetech

Allan, what does the nitrogen pressure test do or catch that the vacuum test doesn’t?