DIY Ductless Installation

For decades, ductless mini-split heat pumps and air conditioners were popular everywhere except the United States. Increasingly, this is no longer true. Many Americans are now turning to these innovative HVAC products due to their compact installation footprint and relatively low cost. The home improvement market has also embraced the systems. Which leads to the question: is DIY ductless installation viable for most homeowners or a job best left to the professionals?

Usually, Trust the Professionals

Ductless mini-splits are smaller and lighter than conventional systems. They don't connect to bulky air ducts. Overall, they're much simpler to install.

That does not mean installation is necessarily easy or non-technical. The average person should not attempt DIY ductless installation. That average homeowner would have to go buy specialized equipment and learn how to use it. By the time they did all that, it is highly unlikely they would save enough money to justify the effort.

So, in most cases, we highly recommend leaving it to a professional.

Except for....

MRCOOL DIY Ductless Installation

We recommend only one ductless DIY product: the MRCOOL DIY. Why? It is the only mini-split designed explicitly for amateur installation.

How do they do that?

The real key is the way they design the refrigerant lines. Typically, a professional needs to flare, vacuum, and properly charge the lines with refrigerant. The MRCOOL DIY gets around that by pre-charging and pre-sealing the lines before they leave the factory. They use special plunger fittings to prevent any refrigerant escaping or any foreign particulate from entering the lines. Which means specialized equipment like a vacuum pump is not required.

The only portion of MRCOOL DIY ductless installation that requires technical help is the electrical. For that, we really encourage our customers to hire a good electrician. Many people do DIY electrical work, but it's just not something we're comfortable recommending.

Have you done your own DIY ductless installation with a MRCOOL DIY or other min-split? If so, let us know in the comments!

13 comments (view/add)
  • srg
    Posted on 6/4/2018

    Ordered a Mr. Cool DIY unit and look forward to installing it. One question: is a torque wrench needed when attaching the lines to the outdoor unit?

  • Kyle
    Kyle from Ingrams
    Posted on 6/4/2018

    According to the installation manual, a torque wrench is not required.

    Posted on 6/4/2018

    Installed 1 week ago took less than 3 hours to have it up and running. The hardest part and most work was pouring the concrete slab, otherwise followed the instructions and everything went smoothly. The unit is pretty quit and cools nicely.

  • Kyle
    Kyle from Ingrams
    Posted on 6/5/2018


  • David
    Posted on 7/3/2018

    Bought a 12K three seasons ago for the bedroom upstairs. Love it. Installed a 18k down stairs last week. Easy install. Cools the entire 1,000 sq ft first floor keep the house about 20-25 degrees cooler than the outside. I use the PVC platform, no cement slab. Works great.
    Funny story: I'm having some work quoted from one of the big box building supply stores, he noticed it and I think I made a sale for Ingrams.

  • albert Nghiem
    albert Nghiem
    Posted on 7/7/2018

    What is a electrical power supply to the evaporator fan ? is it 220 volts or 110 volts ? can it be 110 volts? The condenser needs 220 volts for the compressor to run. the fan also needs 220 volts ????

  • Kyle
    Kyle from Ingrams
    Posted on 7/9/2018

    For the MRCOOL DIY, the air handler evaporator is wired to the outside condenser. The DIY 12k is 110v. The other models are 220v.

  • LF
    Posted on 11/13/2018

    how would you size a MRCOOL DIY unit for a 12ft X 18ft sunroom near Richmond Va with a heavily insulated roof but only single pane glass window walls that are just standard glass. Bought the house and would like to use the sunroom after dark in the winter and during the day in the summer. inside winter temps at night drop to mid 40's and daytime summer temps inside can go to 105+. Need a unit but not sure what size too order...Thanks in advance for the help.

  • Kyle
    Kyle from Ingrams
    Posted on 11/14/2018

    That's not a large area, so the DIY 12k would be your best fit.

  • Tony
    Posted on 2/27/2019

    Living in WI, I'm concerned about how well it will work in subzero temps. When will the unit shut down, and how efficient is it before it does?

  • Kyle
    Kyle from Ingrams
    Posted on 2/27/2019

    The MRCOOL DIY will maintain about 55-60% efficiency down to 17 degrees, and will continue functioning down to around 5 degrees. For cold winters, the best ductless heat pumps are units like the MRCOOL Oasis HyperHeat or the Mitsubishi M-Series.

  • Regina J. Pexton
    Regina J. Pexton
    Posted on 2/27/2019

    I have a mobile home that is 1080 sq.ft. I want to put 2 DIY MrCools in my home. One in the main living space and one in my 11 x14 master bedroom. What sizes should I get? Do you have a cover that hides the wiring and lines? I will have to put the living room unit on the front of my house and I want it to look as neat as possible. Do you have installers in or near Hohenwald Tn. if I cannot get someone to do this for me? Thank you for your time.

  • Kyle
    Kyle from Ingrams
    Posted on 2/27/2019

    For a 1080 sq ft home with an 11 x 14 master bedroom, you could put a DIY 12k in the master and a DIY 18k or 24k in the main living space. Alternatively, you could substitute an Advantage 9k in the master bedroom, but it does require professional installation. We do sell LineGuard kits that you can use to cover the external refrigerant lines and wiring. We do not have installers in Tennessee.

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