# DIY Mini-split in my Garage



## wuddoc (Mar 21, 2008)

Very good review and I agree with you a little planning installation is a no-brainer. We added a Senville 24000 BTU Mini Split Air Conditioner Heat Pump SENA-24HF/Z when we added to our existing shop as support for our in-wall unit in the older part of the shop. Like you we did the installation but left the hook up to a licensed professional since we wanted the extended warranty offered by the manufacturer. Our outdoor unit is on the optional stand to stop shrub, tree trash and rodent nests from clogging the fan.


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## emetric (Sep 21, 2009)

Nice review! However seeing your french cleat wall in pic #2, I am sure that we would all love to see your shop. Any chance you will do that in the near future?


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## ssnvet (Jan 10, 2012)

Nice write up…

I had a two zone system quoted this past summer and they told me $9,900 .... uh… no #^&*## way.

I've since been looking into a DYI install and like what I'm seeing out there.

Great to know the install is straight forward with the freon lines.


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## brtech (May 26, 2010)

I have a Bryant mini-split, contractor installed, in my office, which is add-on space in our house. It works okay, but there is a limitation I did not understand when I agreed to this solution: it can only handle a limited differential between the inside and the outside. In the coldest days (which are minus a few degrees here in Western PA), it cannot maintain 70 degrees. Actually, it can't maintain 70 when it's less than about 20 degrees F. I've had a different HVAC guy than the one who installed it out, and there were discussions with factory techs. The unit is working the way it's supposed to. It's sized correctly for the space, and it can't maintain a comfortable air temp when it gets really cold.

YMMV


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## Breeze73 (Jul 14, 2016)

Darryl,
I've been looking at doing that. But I'm currently applying the finish to a queen sized bed in my shop and there isn't much room in the garage. As a result, my work area is a complete mess. I'll try to get on that in a week or two once I get things put away.

brtech,
That was one of the things I was concerned about when selecting my mini-split. My garage is insulted, as well as the doors, but it is still a garage. There are leaks around the doors and I knew that it might be a challenge for any HVAC to keep up. So when sizing my mini-split, I choose to go bigger than I think what is normally necessary. I'm sure an 18k BTU unit would have sufficed, but I was worried in the dead of winter when it is around 10 F outside, the heat would not be able to keep up. So I decided to bigger with a 24k BTU unit. The larger size cost little more up front (like $100) and probably does cost a little more every month, but it keeps up with the summer heat and the winter cold just fine. It's so nice to be able to come out to the garage in the winter when it used to be like 20 degrees in there, and now it's 65 to 70 (depending on where I have it set to).


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## Breeze73 (Jul 14, 2016)

> Nice write up…
> 
> I had a two zone system quoted this past summer and they told me $9,900 .... uh… no #^&*## way.
> 
> ...


Matt, I purchased the unit from Ingrams Water and Air online. Here is the link.
https://iwae.com/shop/24k-btu-16-seer-mrcool-diy-ductless-heat-pump-split-system-wall-mounted-ha11722.html**

note: I have no affiliation with Ingrams. I am in the Military and just found that their prices and support were great. Plus, I had it about 2 days after I ordered it. The shipping was super quick.

Also, there is a great install video showing the installation in a garage on YouTube. Here is the link for that.


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## Fallon (Nov 1, 2009)

"I have a Bryant mini-split, contractor installed, in my office, which is add-on space in our house. It works okay, but there is a limitation I did not understand when I agreed to this solution: it can only handle a limited differential between the inside and the outside. In the coldest days (which are minus a few degrees here in Western PA), it cannot maintain 70 degrees. Actually, it can't maintain 70 when it's less than about 20 degrees F. I've had a different HVAC guy than the one who installed it out, and there were discussions with factory techs. The unit is working the way it's supposed to. It's sized correctly for the space, and it can't maintain a comfortable air temp when it gets really cold."

That's actually a limitation of pretty much all heat pumps (which is just an AC unit you can run forward or reverse). They are much more efficient than an electric resistor element for heat with a small temperature differential. But they get less efficient the bigger the temperature differential is. And at a certain point their output just drops off to far. That 20 degree mark sounds about right from units I've had in the past.


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## bigJohninvegas (May 25, 2014)

After being quoted around 6K for a mini split system, I too bought the same Mr Cool system this last summer. Had it up and running around the fourth of July weekend. Bought mine through Home Depots web site. Deliverd to my local store for free. Price is the same everywhere is seems, and I figured if I had to return it, it would be to the store and not online shipping it back.
Like Breeze says, true DIY. The system Kept my 3 car fully insulated garage/shop about 650 sqft. at 76 degrees all summer. 
Honestly though, I am not real happy with the remote control. It may just be me, I really have not figured out the programming to it. And the instructions suck. 
Seems like the condenser unit runs all the time. However it never froze up, and kept my shop cool all summer long. even on the 115 degree days. 
I got a late start into the summer season, and am planning a full review in about a year. After It has had a full Las Vegas summer on it. 
Nice review Breeze, 
A little add on, 
I just saw your shop photos, Sure wish I had run my line set indoors. I cut the 3" hole in my wall and ran it outside. Your install looks a lot better, cleaner than what I did. I may have to change it some day.


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## ibewjon (Oct 2, 2010)

I purchased an LG mini split on line and did the install myself, but had my AC guy do the line set, and freon. This unit has a 28 seer for the air conditioning side, and i think a 14 on the heating side. Believe it or not, it is efficient to minus 14 degrees Fahrenheit. I have it in my 16 x 20×10' ceiling shop with 12" fiberglass in the ceiling, and 6" in the walls. Three outside walls. I am a retired IBEW electrician, and did the electrical myself, including hour meters, and kilowatt hour meters to monitor energy usage and hours running. In Illinois it costs me about 25 CENTS a day to cool the shop, and about 50 CENTS a day to heat. Only one couple of below zero days did the backup electric resistance heat kick in. ( Also metered). It is a great system, but all systems rrley on good insulation. This also has internet control, which was great when I was still working, but is not as important now.


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## Upontheridge (Apr 28, 2020)

For those with mini splits in the shop. Have you had any issues with sawdust clogging up filters or fins. Does the Mini Split have a filter that you can change out? I am planning to install a Mr. Cool 24K unit in my shop.


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## bigJohninvegas (May 25, 2014)

> For those with mini splits in the shop. Have you had any issues with sawdust clogging up filters or fins. Does the Mini Split have a filter that you can change out? I am planning to install a Mr. Cool 24K unit in my shop.
> 
> - Upontheridge


I have that Mr Cool system. The filters are a couple of screens that slide into the front of the air handler. To look them when I got it. I really thought that they were junk. But they actually do very well. About once a month I slide them out and clean them with a air hose. Never been totally clogged. I do have a jet air filter I run when doig really dirty work like sanding and router work. 
And a big DC on all the big tools.


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## ibewjon (Oct 2, 2010)

My LG mini has the same type of filter system. A good dust collection system and an air cleaner are essential to having a mini split. You could build a box with additional filters to hang in front of the unit if you have a dusty shop.


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