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What’s the least expensive minisplit, installed?

FrankFulton | Posted in General Questions on

What is the least expensive way to have a mini-split installed in our bonus room?

We need a mini-split in our bonus room in order to meet a HERS reduction requirement for a county tax break. We have only entered this room once in three years; the purchase is really just for the energy model. As long as the unit can stand to be used once a year, it will be fine.


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  1. user-2310254 | | #1


    Have you considered a PTAC or DIY mini split (like MRCOOL)?

  2. carsonb | | #2

    1. Mr Cool DIY ~ $1400.
    2. Buy all equipment yourself, install it, find "a guy" to commission it. Good luck with the latter. ~$3000.
    3. pay an hvac contractor- ~$6k.

    Whatever you get, it will probably be oversized unless you have a huge bonus room, so just find the cheapest thing out there.

  3. FrankFulton | | #3


    Thanks very much. I just priced MrCools, all well under $1000 - this could be a great option.

    Any suggestions for install? I'm not comfortable with DIY here, unless it is paint-by-numbers :-)

    I'd also be curious to hear from others with helpful thoughts.


    1. user-2310254 | | #5

      If you have a regular heat and air guy or gal, that's your best option for getting it commissioned. Ask if he/she will do it as a favor.

  4. FrankFulton | | #4

    This looks fairly manageable, excepting the electric that I would need to source out.

    If you have experience with MrCool, please share.


    1. walta100 | | #8

      Your timing could not be better I install one for a friend yesterday.

      I was impressed the refrigerant connectors with how well they worked.

      The unit was taking in 88°air and blowing 49° air out very impressive.

      The bad is the big coil of extra tubing is butt ugly. In my mind fails the code requirement for a workman like installation.

      Tip when you start threading the connectors together turn then in the wrong direction. You will feel a click once per revolution in the same o clock position if you are lined up correctly.

      Keep the units at least 6 inches from the wall this will make lining up the connectors easier.

      Buy 5 feet of 3/8 soft copper pipe and practices bending it without kinking it.

      If you are interested in some help installing Fulton Mo is not to far away.


      1. Ian_Schwandt | | #10


        How did you run the drain line for the Mr Cool? Did you run it to daylight along the line set? In my previous home I had many issues with the drain on the Pridium units and am looking for better drain options. Connecting it to the plumbing drain system? Haven’t found much info on the topic of draining. For my new construction project I am planning to install either the Mr Cool units or the Denali Air units from Menards.


        1. walta100 | | #11

          I did run it next to the copper.

          This morning my friend texted that there is leaking water. I suspect the drain is pinched somewhere. He will have a look this evening.


          1. walta100 | | #14

            I think I found the leak.

            The Mr. Cool drain line has a slip together connection. This connection is pretty weak and an inch of standing water was enough to make it leak. In most installs the tubes go out the back of the unit and this connection will be vertical and very unlikely to leak.

            My install required the tubes to exit the side of the unit and down thru the existing hole. At some point the tube was above the connector by an inch or so and that was enough pressure to make the connector leak.

            In hindsight I should have made a new hole behind the unit. The install would have been far easier and faster.


          2. walta100 | | #18

            The drain was still leaking I found a 2 inch long section of the hose was damaged at some point.

            The photo with spraying water I was applying pressure so you can see there are several leaks.

            Clearly this tube needed to be treated very carefully.


      2. bfw577 | | #15

        I heard those refrigerant connectors were originally designed by an American company for military use in Iraq and Afghanistan. I talked to a someone that was in the National Guard and installed them. He said everything was cooled/heated with cheap Chinese units with various names from generator power. He said they were crazy reliable and were used mainly because of the extremely dusty environment there.

  5. bfw577 | | #6

    Costco sells the Mr Cool 12k DIY unit for $1099. Costco has an excellent reputation that if you have any issues with a product they sell they will usually refund or replace it.

    1. FrankFulton | | #7

      Thank you BFW!

    2. Deleted | | #9


  6. bfw577 | | #12

    The Mr cool DIY is a good unit for cooling but the heating performance is pretty bad. They start losing capacity extremely quick. I attached a heating performance chart for them.

  7. carsonb | | #13

    I found a listing at neep here for their 3rd gen (latest) 12k diy unit, yeah the capacity drops to almost half at 5F. Still, for some applications and in milder climates this would probably be fine. I'm planning on putting one in a detached office, for which the 12k unit would be oversized anyway.!/product/30946

  8. bliljequist | | #16

    I'm not crazy about the proliferation of these and the likelihood of high global warming potential refrigerants leakage in the hands of clueless homeowners offsetting any carbon benefit...

    1. carsonb | | #17

      How exactly would a "clueless homeowner" leak refrigerant in a pre-charged lineset, which is what the unit being discussed is using?

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