| by Kenneth Chase | 100 comments

DIY Ductless Mini Split Install – MrCool Unit

so on my property I have this beautiful
shed that really isn’t being used for anything other than miscellaneous store
is for odds-and-ends it’s such a shame because it looks much more like a tiny
house rather than a normal shed with that I have decided to turn it into
guest quarters so that when somebody’s staying here
they’ll have their own accommodations and space of course what the be in Texas
AC is a must so that is my starting point
installing a mini split now with the space being pretty small and it’s only
168 square feet I’m going with the only do-it-yourself mini split on the market
currently it’s made by a brand called mr. cool I started by clearing out a
walking path and work area on the wall where I’ll be mounting the inside unit
which is called the air handler then taking some measurements to make sure
the unit would fit I used a stud finder to locate and Mark
the studs inside this back wall then remove the bracket on the back side of
the air handler and started pre drilling 4 holes to mount it when placing this
bracket I lined up one column of holes to be in line with the stud and this
leaves the other side shy of the next stud however so with one screw holding
the bracket in place and a level on top I pre drilled the hole locations for the
second column of screws that wouldn’t hit a stud in this way I could remove
the single screw I placed in the bracket and tapping some wall anchors I made
sure that these were flush and then remounted my bracket next I started
lining out where I needed to drill a hole in the wall for the plumbing that
will connect the inside unit to the outside one these units are supposed to
come with a template but I wasn’t able to locate mine it’s no problem though I
measured over from my left row of holes six and a half inches and made a mark
then I found a circle that was three and a half inches in diameter and traced
around it to cut this out I could have used a hole saw but I didn’t have a
three and a half inch bit so I went with a jigsaw instead I used a drill bit to
punch a hole big enough for my blade to fit in then neatly cut around my pencil
mark that takes care of my inside hole now I need to go to the outside and cut
another one that’s perfectly in line with it if you’re wondering that is my
mother’s finger when you’re punching the center hole of the
inside circle make sure that your bit is long enough to go through the entire
wall and also punch through the outside wall this way you can go to the outside
trace you get another circle that is three and a half inches in diameter and
then cut it out with a jigsaw with a hole cut all the way through I took the
plastic sleeves that come with the unit and test fitted it now they do come
along so that they can fit through a variety of wall thicknesses so I made a
mark on mine where it needed to be cut down then used a jig saw to cut it to
length I place this on the inside hole then capped it off on the outside and
now I have a smooth passage for all of the plumbing of the unit to pass through
the wall so the thing about mini splits is that they are pretty simple to
install but it takes professional equipment to charge their refrigerant
lines the mr. coil unit though comes with the line set this long white line
already charged for you this makes the unit DIY a bulb but it
also means that it comes with a stock length of line set that can’t be cut
down so keep in mind when you’re picking out your location for it that you’ll
need to coil up and stow away in the excess line once I fed through the start
of the line set I paused and also fed in the drainage line this will drain out
any condensation and moisture that the unit creates I push one end through the
wall then connected the other end to the back of the unit making sure to give it
a few tugs and see that it wasn’t going anywhere oh and also it doesn’t say it
in the instructions but there is a plastic corner cap on the backside of
the unit that you need to remove and that’s what allowed the units you mount
flush to the wall whenever you get it up on its bracket having two sets of hands
for this part makes this go a lot easier my mom was around and offered hers up
she got on the outside of the shed and pulled the line as I was on the inside
feeding it through take your time especially if you’re going up a ladder
to get this entire line through without kinking any of those hard lines
let me get up on my stool a little bit just gentle pools at this point now just
try to pull the rigid line if you can’t you just pause for a second once you get
close it is incredibly simple to get the air handler on the mounting bracket as
it how they live that you can set it on and then just let it hang really awesome
once the top is hung you need to make sure the bottom is in line with with
that line stepping inside of its space and then push on it until it snaps into
place and that is the inside unit done but before jumping out to wire in the
outside unit let me talk to you about this video sponsor which is simply safe
simply safe is an incredibly effective reliable home security that will make
sure your home or in my case my shop is safe since building my shop I’ve been
looking into plenty of security systems but settled on simply say for a variety
of reasons I love that all of the devices can easily be set up by yourself
so no waiting on pros to come in it’s very easy and intuitive also it’s very
fair pricing and the fact that there’s no contract or hidden fees is a plus now
even though you’re getting a good rate the system is professionally monitored
24/7 and they’ll call the police if anything should happen and yes the
system still works even if you lose power Wi-Fi or the system is attacked
you can customize your system by picking the components you need or want there
are so many options including cameras motion detectors a smart doorbell and a
variety of sensors that will tell you if a window or door is open if you’re
interested in checking the system out then please visit simply safecom slash
April thank you simply safer keeping all of my tools safe now let’s get outside
to wire in that unit I’m comfortable tackling the simple wiring on my own so
I pulled off the covers and started by wiring in a powerline I purchased
outdoor flexible conduit called liquid tight and this came with a 90 degree
fitting on one end and a straight fitting on the other it also had wires
routed through it went bourbon and me from having to buy a power cord and fish
it through man I just had to strip the ends and
crimp on some Spade connectors in the other knockout I ran in the wiring from
the line set and this comes with a connector already wired on for you I
first terminated the line input ground and neutral wires and this was as simple
as backing off of the screw slipping in that Spade connector I attached earlier
and then tightening back down then I connected the output line which goes up
to the air handler using that simple push together connector they already
wired on and that’s it so next I pushed everything inside so I could close the
cap and reattach it with the screws I moved my unit down to the corner of my
building so that it would open up the back and that’s not only gave me a
better airflow but it also gave me a sneaky spot to coil up my extra line set
and stow it away I don’t currently have power out here so temporarily or maybe
permanently I’m gonna be running it off a quiet generator stowed away in this
little cranny of the building however instead of plugging directly into the
generator I first wired in a fuse disconnect box there’s a fuse which adds
a layer of protection between the unit and the power source so that if there’s
trouble the fuse will trip before damaging the unit after mounting the box
I used one of the bottom knockouts to wire in the other end of the power cord
that runs the outdoor unit finally on the remaining knockout I purchased a
heavy duty extension cord I cut off the female end strip back the ends and wired
it in and I didn’t leave a ton of cord here because honestly the generators
gonna be set right in the spot alright getting down to the end so hang in there
one of the final steps was to try to blend in that line set to the side of
the shed and I found this Raceway material specific for line set at a
local HVAC shop and it was hard finding one that sold to the public so if you
have trouble I know that there are similar products you can purchase
through Amazon once I tidied that up and knew the unit wasn’t moving I finally
connected the line set to the unit with these lines being pre charged you can’t
disconnect these lines once you connect them or how to get professionals out to
recharge the lines so before removing the protective caps and making
connections just make sure the unit is where you want it to be there we go
that is a drastic improvement over yesterday still need some painting on
the trim that I had to put in but the lines that comes out goes down the
Raceway coiled up the excess back here got it all wired in put it in a
disconnect and eventually a generator will go here then I can plug the unit
into whenever I want to use it you even buried the drain line that comes out other than paint that’s a job done and
that’s it overall it’s a very easy install probably the hardest part is
tidying up that line set and honestly it’s not that difficult to do if you’re
looking to install a mini split then I hope this video has helped you out and
of course if you have any questions on what I used in the video there are links
to you down below stay tuned as I do more projects converting the shed into
guest quarters I’ll see you soon welcome to simply safe thank you



Jul 7, 2019, 10:19 pm Reply

Thanks for the video. I always was wondering how these units are charged with refrigerant. Now I know – they come prefiled, and have quick connect connectors to connect stuff.


Jul 7, 2019, 2:52 pm Reply

The refrigerant line set is too long and should not be coiled up in that position, it is also restricting the condenser coil air flow.


Jul 7, 2019, 5:01 pm Reply

How long do these units last? 5 years? 10?


Jul 7, 2019, 6:46 pm Reply

Great ???

Laverne H

Jul 7, 2019, 2:40 pm Reply

How about set back for proper air flow?

Joker 75

Jul 7, 2019, 5:31 pm Reply

your husband is a very lucky man

Kenneth Ringwood

Jul 7, 2019, 6:34 am Reply

Wonderful,Im SOLD.Looking at a 24K BTU for a Enclosed Patio,the Line Set is perfect length as the ceiling in the Patio is 14' Hugh,just will need to drill through CBS Concrete Block for the pass-through,you got a better quality cover for the line set than you could buy at Amazon as its Aluminum not Plastic.Great Job!!Keep Cool!!

Andres Andujar

Jul 7, 2019, 3:26 pm Reply

it was easier just to get the lines from the other side of the wall

I.R. Wayright

Jul 7, 2019, 3:36 pm Reply

What keeps bugs from infiltrating that hole in the wall?


Jul 7, 2019, 9:02 pm Reply

why not mount a few solar panels on top of that shed? Perfect place for it! and you don't have to burn gas to run the AC!

Ace Service’s

Jul 7, 2019, 1:40 am Reply

Great job!

Basim Bsbsbs

Jul 7, 2019, 10:06 am Reply

Good job

Edmund Pangan

Jul 7, 2019, 2:50 pm Reply

She didn't vacuum the line. No pressure test.

Duke Craig

Jul 7, 2019, 2:58 pm Reply

Why would you waste a perfectly fine building on it being a guest house instead of parking motorcycles in it?
Make em sleep in a tent, and by all means install the AC so the motorcycles will be comfortable on a hot summer day.

Pamela Thompson

Jul 7, 2019, 2:37 am Reply

I have a mini-split in the upstairs bedroom of my condo. The old AC unit ducts going into this room were too small, so this room never got cooled off. My AC bill was 200-300 per month for this two bedroom 850 SF condo. Then I put the mini split in and WOW. It cools the entire condo and I rarely have to turn the old AC unit on. My electric bill in the summer is never more than $60 . I keep my room at 68 degrees and am happy as can be!

Ideal Direct Home Improvements Company

Jul 7, 2019, 1:34 pm Reply

Liked and subscribed because you have done an amazing job, especially on explaining ever step making it look super easy!

Paul Cyr

Jul 7, 2019, 1:49 pm Reply

You Rock April!!

I Am Maximus

Jul 7, 2019, 4:23 pm Reply

Its what I was looking for
???? subscribed

Can it be made into a series where several rooms be cooled?

John doe

Jul 7, 2019, 5:57 pm Reply

TBH, judging by how easily you cut a hole through the wall, I would rather cut a larger, box shaped hole in the same wall and install a regular window mounted AC… If you were working on a brick wall or had a semi-detached property with the wall being shared, or were renting and your landlord would not allow large modifications to the property etc,I would understand the necessity for a split unit but in your shed, a split unit is a bit of an overkill. Also it is just for guests so…

Mouse Vision

Jul 7, 2019, 7:59 pm Reply

Who else thought that was JP Sears in the thumbnail?

Peter Paton

Jul 7, 2019, 9:41 pm Reply

WOW, April you are super cute 🙂

Greg S.

Jul 7, 2019, 4:00 am Reply

In this situation (studs) I would get a piece of painted scrap (appliance sheet metal) and double up the bracket underneath to the next stud. Powered nibbler pays for itself in one go.


Jul 7, 2019, 9:33 am Reply

Is the raceway just for looks ?

Alex Carlton

Jul 7, 2019, 6:28 pm Reply

After you attached the lines from the air handler you are required to run a vacuum pump on the system to remove any moisture from the lines and inside the air handler.


Jul 7, 2019, 8:22 pm Reply

That's the most beautiful shed/guest quarter I've ever seen. Would love to have that in my garden ?

becem baccar

Jul 7, 2019, 10:15 pm Reply

Bravo ?


Jul 7, 2019, 10:31 pm Reply

Since there's no power plug that you can unplug when not in use , and you can only turn off the indoor unit by using the remote, doesn't it consumes electricity even of its turned off (remote)?

Usman Ullah

Jul 7, 2019, 11:47 pm Reply

you are awesome!


Jul 7, 2019, 1:25 pm Reply

Hope the generator isn't too noisy…but very nice project and well done.

Zeke Montgomery

Jul 7, 2019, 9:44 pm Reply

Do not leave your line sets coiled up!!!!


Jul 7, 2019, 1:34 am Reply

Well. Did it work? You left us hanging!!!


Jul 7, 2019, 1:58 am Reply

I would put the condensation line in corregated pipe so it doesn't get crushed or clogged

OBServe Garage

Jul 7, 2019, 12:43 pm Reply

April, ALWAYS connect the ground terminal FIRST. When disconnecting, always disconnect the line power, then the negative (neutral). Lastly, disconnect the ground. Stay safe!

Jessica Monson

Jul 7, 2019, 10:48 pm Reply

Does this unit come with a power cord? It sounds like you bought the one you used separately.

Asias Sales

Jul 7, 2019, 1:05 am Reply

Girl you know you are BADD!


Jul 7, 2019, 2:43 am Reply

With that much excess line provided , I could potentially mount the outside unit in another zip code 🙂

Brand GID

Jul 7, 2019, 4:04 am Reply

What kind of installation? The outdoor unit is not fixed, stands on the concrete, there is no normal blowing. Long work will not be this unambiguously.

Casey Muni

Jul 7, 2019, 8:20 am Reply

Installation by the professional will likely quadruple the cost of that a/c. But you still have know or ask for proper way to do it.

gerard haubert

Jul 7, 2019, 8:29 pm Reply

What does your shirt stand for?

Sean Meagher

Jul 7, 2019, 2:26 am Reply

Thanks Greece…i just put one in..first A.C.. I'm hiring professional to do vacuum, cut and flare line set…he wanted $750…im like What..another $700 You would of done all…In the states they charge way to much to install.

Chris Bullen

Jul 7, 2019, 11:17 am Reply

You got skills ! well done smashed it

No Name

Jul 7, 2019, 4:52 am Reply

Outside hole should be angled slightly lower than inside hole for proper drainage.

Sharik Khan

Jul 7, 2019, 9:44 am Reply

So good work I am Indian technician

Miraz Hossain Shorab

Jul 7, 2019, 7:57 pm Reply

Girl. Good work

Original Wolf

Jul 7, 2019, 8:25 pm Reply

Is there insulation in the wall? Seems kind of useless to install an ac, when the heat can get right in again through the wall


Jul 7, 2019, 1:29 am Reply

We install these all the time and she made it look easy its a pain when u gonna run new wires to a breaker box and go threw a 8 inch wall filles with concrete and then cut the copper both ends and make new flares because the mitsubishi mini split says we have two and add a drop of oil to the flare to make a good seal but glad u was able to do it like a pro

Bensons Speedshop

Jul 7, 2019, 5:43 pm Reply

Awesome Informative video, Thanks!!!

Richard Nguyen

Jul 7, 2019, 9:24 pm Reply

Hey my friend where I can get one like you have?

Richard Nguyen

Jul 7, 2019, 9:24 pm Reply

Please let me know thanks

sand sand

Jul 7, 2019, 12:28 am Reply

Wow a beautiful girl

Dennis Clark

Jul 7, 2019, 2:54 am Reply

Great video. Thanks…

Chris Francis

Jul 7, 2019, 7:02 am Reply

Thanks …so you have the cost?

Beautiful Dream

Jul 7, 2019, 10:46 am Reply

Hai, i think you need to keep the pipe insulated. That mean more thicker sponge with reflective aluminium that keep cooler air transfer or transported to the room, which help you to save a lot energy and cost.

Angie Williams

Jul 7, 2019, 6:45 pm Reply

How are you liking this?

Jason Rogers

Jul 7, 2019, 8:34 pm Reply

Soo how is it doing? I’ve looked and only seen not good reviews for mr cool mini splits. And since it’s already been 100+ in Texas I’m in San Angelo how’s it cooling that space

semaj epits

Jul 7, 2019, 4:18 pm Reply

She's a keeper

My Favorite Granddaughter

Jul 7, 2019, 1:51 am Reply

No power out there? Put in solar. I did.


Jul 7, 2019, 1:43 am Reply

Another install video discussed the need to coil that long line horizontally because when it is coiled vertically, if there is condensation, etc. it flows to the bottom and blocks the flow of air – at least that is my understanding of what they posted.

Wenceslas Balima

Jul 7, 2019, 2:07 am Reply


Michael Damico

Jul 7, 2019, 12:05 pm Reply

Does this one do dehumidifing? My mitshubshi does.

Larry Potts

Jul 7, 2019, 10:57 pm Reply

How much would like this cost?


Jul 7, 2019, 7:50 am Reply

That's the coolest "she- shed" I'd ever seen.

Carlos Subic Danger

Jul 7, 2019, 6:59 am Reply

Awesome ?


Jul 7, 2019, 3:17 pm Reply

Not credit at all to the pooch!! that poor pooch probably did about 90% for the hard labor!! Great video by the way!

Greg O’Hare

Jul 7, 2019, 10:35 am Reply

A friend of mine just installed similar unit. Only issue I would point out is that it doesn’t have a fresh air intake. Old fashioned wall unit will allow for either fresh air or recirculate. Both room size and lack of wall and ceiling insulation should be taken into consideration when sizing. Friends seems to struggle to adequately cool space.

David Gregory

Jul 7, 2019, 2:15 am Reply

Your unit should have had a vacuum test run to purge the lines of all moisture prior to charging the unit. Any competent professional would perform this before charging a unit. This eliminates moisture that will turn to acid and ruin the unit over time. 

Next, get rid of the garage door. The lack of insulation and solar gain will make the job of cooling very hard on that unit.

R. T.

Jul 7, 2019, 4:19 am Reply

What a lovely woman 🙂 and yes there is refrigerant in both outside an inside units. All you do is connect them. No need of a vacuum. The lines are insulated so the loss of efficiency is minimum.

Gerardo Aleman

Jul 7, 2019, 6:58 pm Reply

What size shed is it?

Vlad The Impaler Țepeș III

Jul 7, 2019, 2:07 am Reply

Why does Mr. Cool provide such a long line set? It seems to me that if someone needs that much line set, they should look into a different solution. I would never want that much line set coiled up in or out or my house.


Jul 7, 2019, 4:46 am Reply

Honestly, this was great to see. My wife and I currently live in Japan and had to buy two units for our current home, but when we get back we were planning on installing them in the house we have stateside. Luckily, the ones here in Japan are powered from inside the house so we just have to plug them in. Great and informative video. Thank you!

John Becich

Jul 7, 2019, 12:31 pm Reply

Congratulations on your excellence as a teacher… and your videography and audio quality is superb. I notice the inefficiencies; it seems the walls are without insulation in your shed; and I wonder if that glass door is "low e." You ought to protect 100% of that freon line and the electrical feed from sunshine; I suggest radiant barrier material easily bought on Amazon. Clad that dull-metal raceway with shiny aluminum (shiny side OUT) and you'll keep the interior cavity temperate… cooler in summer, warmer in winter. I'm in SoCal and you're in Texas and we both have serious heating from sunshine.

Jeremy Hopper

Jul 7, 2019, 12:48 am Reply

How much did this unit cost?

Mario Hdz

Jul 7, 2019, 3:59 am Reply

Hi April Wilkerson a have a question for u !

Bmw Motorcycle Touring

Jul 7, 2019, 1:56 pm Reply

so how did you handle evacuating the line?

alam alam

Jul 7, 2019, 6:09 pm Reply

What is the price for the unit?

Ahmar Ahmar

Jul 7, 2019, 4:18 pm Reply


M. P.

Jul 7, 2019, 9:54 pm Reply

You are seriously my girl crush. One day… I want to grow up to be you… or at least develop your mad maker skillz!

John Arnold

Jul 7, 2019, 10:08 pm Reply

I think you have to draw down a vacuum on the wall-mounted unit and the tubing that runs to it before you hook it to the compressor? I know it' s precharge, but I think only the compressor is precharged.
I don't think you have to add refrigerant unless you're running over 20ft.
If that's true you may as well cut the copper lines to a more appreciate length.


Jul 7, 2019, 5:02 am Reply

It’s just like hanging an over the range microwave

Corey Hargrave

Jul 7, 2019, 1:19 am Reply

Please tell me more about the glass garage door on this shed…

D Bo

Jul 7, 2019, 2:38 pm Reply

Great job, looks awesome and love that shed! That’s the nicest ‘shed’ I’ve ever seen to just put ‘stuff’. The inspector bought into that! Don’t forget to strap down the electrical at least 12” from any connector. Great job!

nazeer Ali

Jul 7, 2019, 4:37 pm Reply


Jim In UK

Jul 7, 2019, 5:22 pm Reply

At 6min 36 you appear to be screwing black wire to Live and Red to Neutral. In UK that would be the wrong way. Is your Black = Live?

Trisha Waddell

Jul 7, 2019, 10:23 pm Reply


ظافر ذياب

Aug 8, 2019, 7:53 pm Reply

I liked your boots, can you help me get one

67tr876. The mechanical channel

Aug 8, 2019, 3:50 am Reply

April I love the video's but some things should be done by professionals who work with HVAC and Have a 608 Like my self. I see many things worng with this but I tip my hat to you giving it you're best anyway !

Martin Eucza

Aug 8, 2019, 6:55 am Reply

How can you didn't cut off the excess of line set? I least you should strapped it due to the unit vibrations. It looks pretty odd but you got my respect for doing yourself without a Man's help

Les Lieb

Aug 8, 2019, 2:44 pm Reply

You’re a very capable young lady who really knows what is what. Excellent video with no wasted words and your smile makes it way better, overall. Two thumbs up!

more jello please

Aug 8, 2019, 10:28 pm Reply

you get more shit done by 10am than most guys do all day, keep up the good work, oh and why do most guys think that they are smarter than the manufacturer? I bet these ass-hats don't even know what a BTU is without looking it up lol.


Aug 8, 2019, 2:40 am Reply

Are you saying you do not have to do anything except install it. No vacuum needed to make it work?

Mr Cool9001

Aug 8, 2019, 6:00 pm Reply

Excuse me?

Garrett Corr

Aug 8, 2019, 11:22 pm Reply

Don’t call an HVAC or electrical company when your DIY unit decides to break.

English Only

Aug 8, 2019, 5:12 am Reply

You need vacume the pipelines

Erick Blanco

Aug 8, 2019, 4:45 pm Reply

Hi, I had a guy installed my AC unit, very similar to yours, he placed the condenser in a room that I use for storage, but I don't wanted there, I wanted place in the outside corridor. He said that I need a condenser pump to disperse the water created by the unit. Does that sound right to you? I don't see such pump in your installation. can you explain.


Aug 8, 2019, 10:22 pm Reply

Great video. I have one comment. The way you installed your line set, it probably won’t drain out the condensate adequately. It is gravity flow so the drain needs to go downhill and should have been placed on your right side and slanting downward. I am only telling you because I mad that mistake before and filled my wall with water.

Daniele Cohen

Aug 8, 2019, 4:06 am Reply

can you recommend a good mini-split for a small 200 sqft room?

Alain L

Aug 8, 2019, 11:52 pm Reply

Oil trap! 😡

thanh le

Aug 8, 2019, 8:19 pm Reply

Love your videos. Do you have to vacuum the lines

kosmo seedo

Aug 8, 2019, 12:55 am Reply

Its positive a woman tecnician fixing ac thumbs up to her? ac ductless mini mr cool looks cool too

Kyle Shilman

Aug 8, 2019, 1:05 am Reply

I appreciate your DIY efforts but this is something that should be installed by a professional. All units should be started properly by verifying pressures, amp draw, etc. This should not be advertised as a DIY project.

Leave a Reply