Anyone install a diy mini split in their garage?

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Been working on a new garage for the last year. Had to haul out several dozen tandems of soil and pour a 14ft tall wall and hire a couple of engineers because of my weird Minneapolis lot. But that’s all done!

im in the middle of insulating and drywalling It. It’s 24x22x9.5 with a flat roof. epoxied the floor this summer, bought a quick jack, and my two 3 series have a happy place to sleep. Id like to be able to do some work from home, so climate control is in order.

Im leaning towards a diy mr cool unit. I’m familiar enough with hvac to feel comfortable with the install. Has anyone here done it? What’s it been like?
 
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I have not installed one but had one in an apartment. It might have been a different brand though. Either way it worked very well.

A friend has a Mitsubishi for a small office and really likes it.
 

antonmnster

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The big difference between a dyi and others is the use of bolt connections versus soldered joints on the line sets. The diy are “precharged“ and the conventional need to be cut, soldered, vacuumed, then charged.

i think a heat pump will take care of heating most of the time. Seems like it’s not so great below +5f or so. I’m willing to see what happens the first year. Can supplement with gas or electric. When I built the garage I buried the house 200a line and put the service on the garage, so have lots of power.
 
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i think a heat pump will take care of heating most of the time. Seems like it’s not so great below +5f or so. I’m willing to see what happens the first year. ...

Yeah, that won't be ideal but if you can supplement, it would work well for you.

Here is a thread at another forum where we just hashed this all out in some detail, various makes; might add to your thinking.

https://www.ar15.com/forums/general/Mr-Cool-mini-split-anyone-/5-2596917/

My parent's have one in their house (self installed, but not by me) and I and my dad installed one in a guest house last year. Very happy w/results and comfort and cost savings overall w/both units.
 
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The big difference between a dyi and others is the use of bolt connections versus soldered joints on the line sets. The diy are “precharged“ and the conventional need to be cut, soldered, vacuumed, then charged.

No. Regular non-DIY minisplits:

1)Use flare connections. They are not soldered.

2)Are pre-charged. You must flare the lines, connect them, pressurize with nitrogen and check for leaks, then vacuum them down. Then release the charge.
 

JHZR2

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Not in my garage, but did one for part of our kitchen/butlers pantry. It required flared connections, so get a good Yellowjacket tool and the right nylog. Knock on wood no leaks yet after many years.
 
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Been working on a new garage for the last year. Had to haul out several dozen tandems of soil and pour a 14ft tall wall and hire a couple of engineers because of my weird Minneapolis lot. But that’s all done!

im in the middle of insulating and drywalling It. It’s 24x22x9.5 with a flat roof. epoxied the floor this summer, bought a quick jack, and my two 3 series have a happy place to sleep. Id like to be able to do some work from home, so climate control is in order.

Im leaning towards a diy mr cool unit. I’m familiar enough with hvac to feel comfortable with the install. Has anyone here done it? What’s it been like?
Have you gotten any prices on what it would run to have it installed? I'd be curious because I've been thinking about putting one in my garage to help cool things down in the high temp / humidity conditions.

But I have zero experience with refrigeration, and this wouldn't be a project I would want to learn on.
 
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I have a Bryant installed 2-ton mini-split heat pump in my 30x50x10 shop. Building is well insulated with 6" walls and 9" ceiling. Have two ceiling fans that can help with circulation, but I rarely need them. Keeps the temperature in a comfortable range. With a 20-something SEER, it hardly affected my monthly power bill.
 
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I think it’s a good idea especially for cooling. As for heating, give it a try but on really cold days you might need supplemental heating down on the floor via an electric heater. That is just my guess.
 
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If Warranty is a consideration: I just had Mitsubishi mini split AC/heat pump installed (5 inside evaporators [[email protected] BTU, [email protected] BTU and one 16k BTU] on one outside condenser unit) installed by a Mitsubishi certified contractor and that provides a 12 year all inclusive warranty - anything broken gets fixed. Using a non certified installer I recall gave a 5 year warranty on parts only, not leaks or other installation issues. Self installed unit I’d expect the warranties to be even less.
 
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I've installed 1 mini split before. It was an easy process. It was BlueRidge brand if I remember correctly.
 
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On topic. FYI.



I like that video. I would have secured that extra line coiled to the building more. A strong wind might jiggle it around.

The only thing he didn’t mention is that the remote on these things actually monitors the temperature. Like a car fob it sends signals to the unit. The location of that remote is important.
 
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I like that video. I would have secured that extra line coiled to the building more. A strong wind might jiggle it around.

The only thing he didn’t mention is that the remote on these things actually monitors the temperature. Like a car fob it sends signals to the unit. The location of that remote is important.
PimTac - Do you know if the remote works the way you described on the Mitsubishi mini split’s? I have been using one remote for two units on my first floor and temperature does seem to be a bit wonky to use a technical term. I was trying to keep one of the remotes as a spare since remotes seem to grow legs and disappear in my house. Plus the boss didn’t like the look of the remote mounted on the wall, she may have to get over that if it means the mini’s will provide even temperatures.
 
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If Warranty is a consideration: I just had Mitsubishi mini split AC/heat pump installed (5 inside evaporators [[email protected] BTU, [email protected] BTU and one 16k BTU] on one outside condenser unit) installed by a Mitsubishi certified contractor and that provides a 12 year all inclusive warranty - anything broken gets fixed. Using a non certified installer I recall gave a 5 year warranty on parts only, not leaks or other installation issues. Self installed unit I’d expect the warranties to be even less.

There is no warranty on Mitsubishi self installed units.
 
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PimTac - Do you know if the remote works the way you described on the Mitsubishi mini split’s? I have been using one remote for two units on my first floor and temperature does seem to be a bit wonky to use a technical term. I was trying to keep one of the remotes as a spare since remotes seem to grow legs and disappear in my house. Plus the boss didn’t like the look of the remote mounted on the wall, she may have to get over that if it means the mini’s will provide even temperatures.


I cannot be 100% sure but my guess is that the remotes work that way on the Mitsu. You may have to look it up online or in your manual to be sure.

In my other house I have five units (Panasonic and Sanyo) and they all have their own remotes. They do not work with the other units. Every time I changed the batteries I had to pair the remote to the unit.

Another clue would be if the manual says to keep the remote away from hot or cold surfaces or things. That will affect the temperature signal being sent to the unit. They usually specify a distance as well.

Pretty much every split unit I’ve seen uses the remote for temperature control and monitoring.
 
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2)Are pre-charged. You must flare the lines, connect them, pressurize with nitrogen and check for leaks, then vacuum them down. Then release the charge.
Depends on the length of the line-set. My Mitsubishi came pre-charged for 25 ft of line set. Anything longer than 25 ft, it is x oz per ft. The charge must be weighed in, just like an automotive a/c system.
 
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Depends on the length of the line-set. My Mitsubishi came pre-charged for 25 ft of line set. Anything longer than 25 ft, it is x oz per ft. The charge must be weighed in, just like an automotive a/c system.

I think that's pretty much the standard. All of the split-system condensing units I've looked at the spec sheets for say they're pre-charged for 25 feet of line set.

The longest line set I ever saw was around 100 feet, on a commercial/industrial building. The pipes were 3/4" and 1" as I recall.
 
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