What are Pre-Charged Line Sets?

You often send us questions about pre-charged line sets, what they are, how they work, and which ductless mini-splits can (or can't) use them. Here are the answers you need to know.

What are Pre-Charged Line Sets?

During a normal HVAC installation, a professional needs specialized equipment and training to connect refrigerant lines. They must properly measure, vacuum, and charge the system. This is essential to effective and efficient performance.

Pre-charged line sets don't need any of that. They plug in relatively quickly and easily, because they come straight from the factory sealed and pre-charged (hence the name) with the appropriate refrigerant.

How Do Pre-Charged Line Sets Work?

Connect the custom lines to the custom condenser, tighten everything up, open the valves, and you're up and running. The specialized fittings on the condenser and line prevent any refrigerant from escaping during installation.

Which Mini-Splits Use Pre-Charged Line Sets?

To the best of our knowledge, MRCOOL DIY ductless mini-splits are the only ductless split systems that currently use pre-charged line sets. There could be some knock-offs out there. For right now though, no other company supplies pre-charged line sets on anything close to the same scale. Basically, if you want a ductless unit with pre-charged line sets, buy a MRCOOL DIY.

Now, we must specify that not all MRCOOL ductless mini-splits offer this capability. The MRCOOL Advantage, and Olympus products all use conventional line sets. An installer must connect, vacuum, and charge these models just like any other normal mini-split. So don't buy a MRCOOL Advantage to save a few bucks and expect it to be as easy to install as the MRCOOL DIY. Same brand, different products.

Questions or Comments?

Do you still have questions about pre-charged line sets? Or do you just want to tell us what you think? Let us know here, on Facebook, or on Twitter.

10 comments (view/add)
  • Joe Osgood
    Joe Osgood
    Posted on 8/9/2019

    Can these lines be disconnected without losing the charge? Example. To move the condenser for service.

  • Kyle
    Kyle from Ingrams
    Posted on 8/12/2019

    With the MRCOOL DIY, if you disconnect the unit correctly, it will not lose the charge. That is not something they recommend though.

  • Ken ICE-Ashbrook
    Ken ICE-Ashbrook
    Posted on 8/16/2019

    Are the compressors pre-charged too? Seems like there would be a small vacancy in it to be evacuated?
    Thanks for great product.

  • Kyle
    Kyle from Ingrams
    Posted on 8/19/2019

    Yes, the MRCOOL DIY condenser is pre-charged as well. There is no need for any evacuation with the DIY.

  • Sebastian
    Sebastian
    Posted on 8/18/2019

    I need a system for 3 small room to install myself. Can you do a diy condenser connected to 3 rooms?

  • Kyle
    Kyle from Ingrams
    Posted on 8/19/2019

    Unfortunately, that is not possible at this time.

  • michael meglen
    michael meglen
    Posted on 8/19/2019

    Are there any diy for a 2 room system

  • Kyle
    Kyle from Ingrams
    Posted on 8/20/2019

    The MRCOOL DIY is currently only available in a single-zone installation.

  • Mike
    Mike
    Posted on 8/23/2019

    What if I need like 35 feet to go from a room over garage to condenser can I get a longer line?

  • Kyle
    Kyle from Ingrams
    Posted on 8/23/2019

    At the present time, the only pre-charged linesets we know of are 25'.


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