Mr Cool DIY gen 5 "review"

[Russell_Reid]

After the bitterly cold week (for Texas) due to winter storm Fern I wanted to post my experience with the Mr Cool DIY gen 5 mini splits I installed in October 2025. They have easily held temp in my shop even when it got down to 12F. I had them set to 62 and they had no issues holding that. Now, I have 5 1/2" of spray foam insulation on the walls and underside of the roof. But I still find the performance phenomenal. This was the first time I have installed DIY mini splits and I found the process well within my capabilities. I have the 36K multizone system with an 18K wall unit in my 600sq ft shop and two wall units (12K and 6K) in the 600sq ft that is my wife's studio for her business. Both sides performed equally well.
The only tool I bought specifically for the install was a Vevor torque wrench with an adjustable wrench head. The instructions provided a method to tighten the line connectors without one but I decided to use the torque settings just to be sure I got it right. I leak tested the connections multiple times at different run cycles of the system before buttoning up but never found any leaks.
I am very pleased with the system and definitely recommend it.

 

[shade]

I also posted similar on my Gen 5s. Held temp just fine when it got down to single digits

 

[WildBill]

I installed the Gen4 setup in my shop and am extremely happy with it 4 years later. It works great. It was not designed for really cold temps so when it gets around zero here the output air temp starts dropping into the 70s, but that's still enough to heat my shop fine. I believe it was rated to -5F where the Gen5 is rated to -13F.

 

[Jerry1985]

That's impressive performance for Texas cold - good to know the DIY install went smoothly since I've been eyeing these for my own shop.

 

[Mike65]

My wife & I are considering a mini split system for our garage/shop & looking at getting either a Sanville or Mr. Cool 18K system. Thanks for the review.

 

[Russell_Reid]

Yesterday was in the teens with bitter wind chill. I spent most of the day in the shop with it set at 65F. Held temp just fine but it did go into defrost mode fairly often. But my home heat pump (3 ton central air) was doing the same. I am really happy with the heat performance. My heat pump experience says the cold weather is harder for the pump to deal with. So the AC performance this summer should be great I will have to update this after it's 105F outside.

 

[Mikes61]

I live in Southern CA. so the winters are mild here, but I love my Gen. 5 Mr. Cool, 36K, Advantage series. I fired it up a couple weeks ago when it was 36* here. It immediately started blowing warm air. I shot my laser temp. gun into the oscillating vent and the heat gun read 113*. I couldn’t be happier.

Just a heads up for anyone thinking about getting one. I didn’t get the large pipe flare just right on the install and it leaked over a 3 week period and stopped working. I had to have a HVAC buddy come over and redo the flare and use sealant on the flare. I should have used that the first time. He evacuated then recharged the system and everything is good now.

 

[minytrker]

Hope your last longer than mine, see my post about going through 4 of them.

 

[Chuckster in NJ]

Hope your last longer than mine, see my post about going through 4 of them.

Link to post?

 

[minytrker]

https://www.garagejournal.com/forum/threads/4th-mr-cool-minisplit-died.554766/#post-11509431