
DIY ductless heat pumps · Heat and A/C
One outdoor unit. Up to 6 rooms. Install it yourself.
- Pre-charged quick connect line sets
- No vacuum pump needed
4.8/5 from hundreds of reviewsAuthorized dealer
MRCOOL® DIY 5th GenR-454Brefrigerant
Shop MRCOOL DIY 5th Gen
Find your system in three steps
Pick how many rooms, then the total square footage you want to heat and cool. One room is Single Zone, two to six rooms is Multi-Zone.
3Pick your line
Prices shown for the size you picked.
Every Multi-Zone system is MRCOOL DIY 5th Generation
MRCOOL’s latest DIY line, and the only one that runs 2 to 6 rooms off one outdoor unit.
- Install it yourselfR-454B pre-charged line sets, no vacuum pump or HVAC tech
- Heats in winterHeat pump keeps heating down to −13°F outside
- Each room its own tempSet every room from the app, Alexa or Google voice
- Warranty, even DIY5 yr parts, 7 yr compressor + lifetime option
Want to mix wall units and ceiling cassettes? Build your own →
1 room, 351–500 sq ft
DIY 5th Generation, 12K BTU, $2,359
Not sure? Call +1 (844) 999-97253Pick your line below
Want to mix wall units and ceiling cassettes? Build your own multi-zone system →
Compare series
Three DIY lines, side by side



Shop by space
Where will it go?
One room (Single Zone)
Several rooms, one outdoor unit (Multi-Zone)
A typical bedroom is 150–350 sq ft, so it needs a 9K BTU system (115V circuit).



A typical home office is 150–350 sq ft, so it needs a 9K BTU system (115V circuit).



A typical kitchen is 351–500 sq ft, so it needs a 12K BTU system (115V circuit).



A typical living room is 501–750 sq ft, so it needs a 18K BTU system (230V circuit).



A typical garage or shop is 751–1,000 sq ft, so it needs a 24K BTU system (230V circuit).



A typical large open space is 1,001–1,500 sq ft, so it needs a 36K BTU system (230V circuit). Only the DIY 5th Gen comes in this size.
For 2 rooms, one outdoor unit runs an air handler in each room. Add up the square footage of all 2 rooms and pick the outdoor unit that covers it.





For 3 rooms, one outdoor unit runs an air handler in each room. Add up the square footage of all 3 rooms and pick the outdoor unit that covers it.





For 4 rooms, one outdoor unit runs an air handler in each room. Add up the square footage of all 4 rooms and pick the outdoor unit that covers it.




For 5 rooms, one outdoor unit runs an air handler in each room. Add up the square footage of all 5 rooms and pick the outdoor unit that covers it.



For 6 rooms, one outdoor unit runs an air handler in each room. Add up the square footage of all 6 rooms and pick the outdoor unit that covers it.


Sizes are for a typical room with average ceilings and insulation. Go up a size for high ceilings, lots of sun or a kitchen with heavy cooking. Not sure? Call +1 (844) 999-9725.
Award-winning MRCOOL® DIY
FAQ
Questions we get asked most
What’s the difference between DIY Select, EasyPro and 5th Gen?
All three are MRCOOL DIY systems with pre-charged Quick Connect line sets and R-454B refrigerant, so you can install any of them yourself.
- DIY Select, lowest price: single zone, 9K to 24K BTU, up to 17.5 SEER2, heats down to −13°F, white or black indoor unit, 1 yr parts and 2 yr compressor warranty.
- DIY EasyPro, mid-range: up to 20.2 SEER2, heats down to −13°F, adds leak detection, Follow Me and a Gold Fin coated outdoor unit, 3 yr parts and 5 yr compressor warranty plus a lifetime option.
- DIY 5th Gen, top of the line: up to 23.6 SEER2 single zone, sizes up to 36K BTU, the only line that does multi-zone and ceiling cassettes, 5 yr parts and 7 yr compressor warranty plus a lifetime option.
How does a mini split work?
It’s a heat pump in two parts. The outdoor unit holds the compressor, the indoor unit (air handler) hangs on the wall and blows the air, and a copper line set connects them. In summer it moves heat out of the room. In winter it runs the other way and brings heat in from outside. It cools, heats and dehumidifies, and the inverter speeds up and slows down to hold your temperature.
How does a multi-zone system share its power between rooms?
One outdoor unit feeds every room, and each room has its own air handler and temperature. The outdoor unit has a set capacity, and the rooms share it.
Example: an 18K BTU outdoor unit with three 9K air handlers (27K in total). If one or two rooms are running, each gets its full 9K. If all three run at full power at the same time, the system splits the 18K between them automatically, so each room gets about 6K.
That’s why you size the outdoor unit for how many rooms you run at the same time, not just how many rooms you have.
Do the air handlers have to add up to the outdoor unit size?
No. The indoor units can add up to more than the outdoor unit, within the limits in that outdoor unit’s manual. If you often run every room at once, pick the outdoor unit that covers the total so no room has to share.
Do I need an electrician?
Not for the refrigerant side. The pre-charged Quick Connect line sets mean no HVAC tech, vacuum pump or gauges. The power is different: the outdoor unit needs its own circuit (115V for 9K and 12K single zone, 230V for everything else) and a disconnect next to it. Many states require a licensed electrician for that part, so check your local code. It’s a much smaller job than a full HVAC install.
Does installing it myself void the warranty?
No. MRCOOL DIY systems are built for homeowners to install, and the warranty covers a DIY install. Register the system with MRCOOL after you install it, since the warranty belongs to the original registered owner. Each line has its own terms, which are on our manuals page.
Will it heat my home in winter?
Yes. DIY Select, EasyPro and 5th Gen all keep heating down to −13°F outside. In very cold areas, size up or keep a backup heat source for the coldest days.
What if my run is longer than the line set?
Pre-charged line sets come in 16, 25, 35 and 50 ft, and they can’t be cut. For a longer run, join a 50 ft line set with a 16 ft or 25 ft one using a coupler kit, for 66 ft or up to 75 ft max. Pick the shortest length that reaches and coil the extra neatly.
Which one should I buy?
- DIY Select if you’re on a budget and cooling or heating one room in a mild climate.
- DIY EasyPro if you have real winters and want more features without the top price.
- DIY 5th Gen if you need several rooms, the biggest sizes, the best efficiency or the longest warranty.
Still not sure? Call +1 (844) 999-9725 before you buy, Monday to Friday, 9 AM to 5 PM EST.
What comes in the box?
A single zone system ships with the outdoor unit, the indoor unit, a pre-charged line set, the remote and mounting hardware. Multi-zone systems are built room by room: the outdoor unit, an air handler for each room and a line set for each room. The electrical disconnect and whip aren’t included. We sell them under Accessories.
MR COOL DIY IS THE BEST.
“I’ve had for about a year now and the performance has been flawless. It was a diy installation and I didn’t have any problems.”
Mr. BakerBest price and fast shipping
“Good experience, best price and fast shipping. Had a question and they got back to me quickly. I bought the Mr. Cool 36000 btu 3 zone mini split.”
Barry BowenGreat people
“Easy to talk with, made sure I was getting the right system for my needs, great price, and followed through with communications till delivered.”
Pete SwegerAs easy as they claim
“It was actually as easy to install as they claim it is… couldn’t be happier with the performance so far.”
JimPiece of ‘Cake’
“The rep on the phone was helpful with confirming that… I’m amazed at how straightforward the process is. Should be fun, and I’ll save a lot of money.”
Byron GabrielsenDIY 2 zones, 18k
“Packaging and shipping was great. Response time to questions was good. The two zones are performing nicely, and super quiet!”
K. WestfallDelivery handled
“Your help coordinating and managing the delivery was excellent. You have a great team.”
Andy ArenthVery helpful sales
“Cool-minisplits website beat everyone on price… I called and found out that they are very reliable… Items shipped out quickly and arrived in good condition.”
Robert JohnsonGreat customer support
“The order came quickly. One part was damaged by the carrier so I called and they immediately shipped a new part.”
Zac HGreat and honest business
“The 24k Mr Cool was a perfect solution for my garage… Easy install and the staff are always there to answer any questions.”
Todd BaileyEasy install
“Easy install. Took me 2 full days to install 4 wall units.”
MichaelMr. Cool as a DIY project
“I was very interested in the DIY portion of the product. It was involved, but I’m fairly handy and found it very doable and everything works fine.”
WaltGreat service
“Purchase went without a problem and all my questions were answered without delay. I was notified when the unit shipped.”
Scott IverslieAttention to detail
“I threw him so many curveballs and order changes and he still got it all correct… Appreciate all the personal attention to detail and following up.”
Tim HedrickTop notch
“Their customer service is too notch! The product is amazing!!!! … I recommend this to any Contractor any homeowner anyone who’s looking for a mini split system!”
Dean R Sun
Real people. Honest advice.
Not sure what size you need? Call us first.
+1 (844) 999-9725Mon–Fri, 9 AM–5 PM EST
- Free shippingOn kept orders, the 48 contiguous states
- Authorized MRCOOL dealerFull manufacturer warranty on every system
- Rated 4.8/5From hundreds of customer reviews
- Expert supportHelp sizing your system before you buy


