Anyone running a mini split in their shop?

brdobbs

New User
Beau
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 a 600sq shop with a large open ceiling. I'm running this one from Amazon. I went with a smaller unit after some forum research that recommended smaller to help keep the shop drier. It runs longer for a cycle, which allows more air to get circulated through it. I haven't had any issues with keeping my shop at a comfortable temp year round.
I did have a HVAC guy come and draw a vacuum in the lines after I installed it. I think he charged me $100 total. I did all of the install on my own, including pulling the wiring (I wired my entire shop when it was being built). https://www.amazon.com/gp/product/B08WCTRSW4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
 

jgt1942

John
User
I had two Daikin units installed, in my office (about 225 SF) 18,000 BTU unit was installed. In my workshop (about 1425 SF) a 24,000 BTU unit was installed. I have 12 foot ceilings. The total cost was $8,860. I decided to go with an installer based on my son's experence with a DIY installation. However, after using the units for a year I'm sorry I did not go DIY. (1) I think I paid a premium for the install (2) both the installer and Daikin have VERY POOR customer support. Daikin did not answer any of the questions I had and just refered me to my installer. Initially the installer responded but after a short period time he stopped answering my emails. The thermostats are not the best. In my office I installed a Cielo unit. It has been better but I need to restudy the instructions and see what I have done wrong. The support from Cielo has been great and they are attempting to correct issues with the software. It has been several months since I contacted them and I keep forgetting to call them because I'm busy with other products. Also, I stay up very late, often I'm going to bed between 0500 and 0700. Of course I then sleep well into the daylight hours.

Since my install, I've watched several YouTub videos of DIY installations. If I were to install another mini-split it would be a DIY.
 

HITCH-

Hitch
Corporate Member
This is an interesting idea.
This guy created a secondary filter box for the mini split in his woodworking shop.
I wonder if this strains the unit?

 
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AllanD

Allan
Corporate Member
Looks like a good idea for a wooshop to me. About the only disadvantage of mini splits is not having a disposable filter. That should not be a problem in theory as long as there is enough filter area. I'll leave that for someone else to figure out but the mini splits I've seen don't blow a real high cfm.
 

Westpacx3

Jim
Corporate Member
Another Mr. Cool DIY 18k owner. I installed our in a 600 sqft 2-car detached garage with 9' ceilings. It replaced a "portable" AC unit that was loud and didn't work well for cooling and two (in-efficient) radiant cove wall-attached heaters which were quiet, but also very slow to heat. The mini split indoor noise level is *very* low -- just the fan, which is quiet. Outdoor noise level is quiet as well.

I think the new (3rd generation) Mr. Cool DIY units come with a short (2-3 ft) piece of line on the air handler and the rest of the lineset separate for easier installation. I'm not sure if anyone sells it with a shorter lineset though -- 25' is what HD/etc. sell it with.
I got my 18k from Ingram on line. Line set was 16 or 25 ft and they had plenty of scratch and dent models available when last I looked. It dropped my price 500.00. It was a 3rd Gen. Hardest part of the install was connecting the lines to the unit. I had a wall bracket and my angle was real tight but I got it in. I was a bit intimidated man handling that thin copper there. I did nit mount my unit on the ground as I did not want dirt and grass etc getting all over it.
 

HITCH-

Hitch
Corporate Member
Looks like a good idea for a wooshop to me. About the only disadvantage of mini splits is not having a disposable filter. That should not be a problem in theory as long as there is enough filter area. I'll leave that for someone else to figure out but the mini splits I've seen don't blow a real high cfm.
One flaw in his design is that the front panel on the unit can't be raised fully as it hits the filter. It might be a better solution to have the filter box such that it easily attaches/removes from the wall. I think that it could be made much lighter than this one is.
 

Westpacx3

Jim
Corporate Member
This is an interesting idea.
This guy created a secondary filter box for the mini split in his woodworking shop.
I wonder if this strains the unit?

I thought it would strain the unit so I just fitted a cheaper and thinner filter above the intake. Basically just hung it above it and cut the cardboard so it would drop over the front of the unit some. It does not catch it all but I post a filter clean out date chart on my door and clean it out every so often. You will not keep all the dust out and I sure don't want to buy a new compressor or unit because I did not want to clean up dust in a wood shop.
 

bcbrown

New User
Bob
I also have a 34k Mr cool DIY mini split heating and cooling 1200sq ft with 10 ft ceilings. It’s been working great. Even heated the building easily during the cold spell in December. I ran it for a week keeping the inside around 55* it got down to 5* here. My electric bill increased by 10$. The shop has it’s own meter so it’s easy to track. I normally only turn it on when I’m in the shop. Easy install and no charging required
 

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HITCH-

Hitch
Corporate Member
So I have done some more research.
I am looking at a 12,000 BTU /220v 20.5 Seer unit from Pioneer. The unit will cost $883 and is eligible for the 30% tax relief credit.
I called around to get a quote from an HVAC tech to do the nitrogen pressure test and vacuum on the lines. The best quote I got was for $450-500.
I called Pioneer after reading their installation manual. They do not require any part of the installation to be done by an HVAC technician. You can DIY and have full warranty.
I spoke to one of their technicians and asked about the nitrogen pressure test. It is not mentioned anywhere in the installation manual. The technician said that they do not require it because most people do not have the necessary equipment to do it. He said that it is an industry standard though, and they do recommend that you do it.
For $215 I can buy a vacuum pump, gauges, nitrogen tank regulator, and rent the nitrogen tank.
So for about $1,100 all in I can get a 12,000 BTU unit that I can install myself that is fully waranteed. That is about $600 less than a comparable Mr Cool unit. I will own the installation tools and I can use the vacuum pump for my lathe vacuum chuck.
 
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Pat M

Belg
Senior User
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).
Which brand did you get and could you also send me the contact info for the installer? Thank you
 

Pat M

Belg
Senior User
The vacuum decay test does serve as a double check for leaks but it is very necessary to remove air and moisture before adding the refrigerant. I pull it down to 200 microns of vacuum.
What type of unit(brand) do you prefer as a pro? Do you do the final hook up type job? I'm an electrician and could do all the pre-installation work.
 

AllanD

Allan
Corporate Member
I just installed another mini-split about a month ago. It was for the basement of my shop. Besides storage that is where I have my blast cabinet and parts washer among other things and it was too warm for comfort. This time I bought a Senville 36K BTU directly from Senville. I ordered the option with a 50 ft line set which means I had to add a small amount of refrigerant. It's working great.

Belg, I sent you a PM with my phone number and email. Or at least I think I did if that is what Conversations is called now
 

jlwest

Jeff
Corporate Member
I had a Daiken system installed. Works great and has a 10 year parts and labor guarantee. Because of the wood dust I place a additional filter over the air inlets.
 

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