How-To: MRCOOL DIY Mini Split Installation
Just when you think your HOT and HUMID night out in the garage can’t get any worse, the mosquitoes swarm in from the open garage door!
Enough was enough, it was finally time to get some air conditioning! And not just any old window shaker, a proper mini split that is efficient and super QUIET!
Enter MRCOOL, a heat pump operated mini split that can offer BOTH heating and cooling functions to an interior space. A “mini split” consists of an air handler inside, and a condenser placed outside. You hook up both with a lineset that carries refrigerant.
Now normally this type of install would require a HVAC professional to perform the install, which adds $$$ to the project….big time! Well, with the MRCOOL Diy system, this is a job that you can totally do yourself. In fact, I did the entire job myself with the exception of having my wife help me carry the 100 pound condenser outside (my back is not the best LOL). So the part that makes this system DIY friendly, is the precharged lineset that takes 2 adjustable wrenches to assemble. It doesn’t get any easier than that. However, the lineset is only available in 25′ at this time, so plan your install accordingly.
MRCOOL Products In This Video
MRCOOL Diy 3rd generation E star 18k
Lineset guard kit (I used 2 kits for my run)
MRCOOL smart controller (so you can use the smartphone app)
MRCOOL mini thermostat (this replaces the remote if interested)
Wiring
The instructions for the 18k unit state the 12ga wiring must be used, along with a 20A breaker. Since this unit is 220V, I ran 3 wires (2 hots and a ground). Also, the wiring is super easy since everything is labeled.
12ga THHN red (I used yellow since I had some leftover)
Helpful Resources
I think the most challenging part of this install for most people will be the electrical work. Below are some links that will help you out.
Non contact voltage tester (detects live electrical wires easily)
Conduit bending theory (I learned how to bend conduit from this site)
Conduit fill calculator (can’t have too many wires per code)
Wire lube (everything is a little better with lube)
Matt,
If it is so hot out why are you wearing a hoodie sweatshirt during the whole install? Or was the whole sweat and bugs clip staged?
Remember you don’t necessarily need to cool the whole space. The object is to keep YOU cool. So if you unit is undersized a bit try to set it up where the cool air flow is directed towards you. The rafters, XR100 and tool boxes don’t really care too much about a few degrees one way or the other. 🙂 On the other hand if you have several folks in the same garage or you need to move around a lot, keeping the entire place comfortable is more important. Good real life video.
Install took place April thru June. In April, we had temps in the 30’s with snow flurries. June temps in the 80-90’s. Intro was after a 2 mile jog and bug sound effect LOL.
Real nice job, friend! You made the entire install process look rather easy. I give you credit for tackling the job solo and doing your own electrical work. Are you a licensed electrician as for my area, it’s required for county inspection. Nice job and I want a Mr Cool!!
Thanks! No I am not a licensed electrician. Don’t call the village inspector on me LOL.
Hey Matt
Your MrCool A/C DIY kit is brilliant and you did a cracking job of the installation. You remind me of me except you’re a lot better. I simply love a challenge and especially with something I’ve not attempted before. Well played!
Thanks for the compliments, Paul!
I was looking into this system, then I called them, and was told the units are manufactured in a country that I am boycotting,…Looking for an alternative.
Well then I think you may have a hard time finding one that fits your needs.
Hey great job on this mr cool install video. It was probably the best I saw before installing my own. I had a question. I noticed you had a fitting connecting the signal wire to the condenser.
What type of fitting is that?
Thanks.
The connector:
https://www.homedepot.com/p/1-2-in-0-260-0-375-Strain-Relief-Cord-Connectors-2-Pack-21691/100136271
So the 240v unit only requires 2 conductor and a ground (L1,L2,G)? Not a 3 conductor and ground (L1,L2,N,G)? Reason I ask is I already have a 240v (12g) run (L1,L2,G) on a dedicated 20amp breaker that was used for a baseboard heater (removed) that I can retask.
Yes, only 2 hots and a ground is needed.