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Community and Q&A

Protecting Refrigerant Line Insulation from UV Damage

Trevor_Lambert | Posted in General Questions on

I have two minisplits, one Fujitsu and one Senville. The Fujitsu is 3 years old, the Senville is 2 years old. Both have line set covers, but there’s a section of lines between the outdoor unit and the wall that are exposed. I noticed the other day that the white, foam insulation on the Senville unit has deteriorated badly in only two years. The Fujitsu has black rubber insulation, similar to the more expensive type you see for domestic hot water lines. And yet, it is rotting away as well. Not as badly, but certainly in need of replacement. I found this somewhat surprising. Both units are on the north side of the house in zone 6, so sun exposure is definitely on skimpier side.

My question is what should I use to cover these after replacing the insulation? Some kind of wrap? A bigger sleeve of sacrificial foam insulation? I can’t picture a rigid option that wouldn’t look ghetto.

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  1. gstan | | #1

    I have had good luck with a simple coat of latex house paint - seems to stop
    the deterioration and using the leftover touch-up paint matches the house color.

  2. Expert Member
    BILL WICHERS | | #2

    If it's only a short exposed part, I would wrap it with Scotch 88 tape, which is available in a wider 1.5" roll that is great for this kind of thing:

    This is a thicker than usual black electrical tape of good quality, and I've seen it go 15+ years outdoors without any trouble. If you take some care, you can get a nice spiral application of tape that will look professional.


  3. charlie_sullivan | | #3

    A third option would be aluminum tape, but the Scotch 88 would likely look better.

    1. Expert Member
      BILL WICHERS | | #4

      The downside with aluminum tape is that it's nearly impossible to apply without a bunch of wrinkles, and I'd imagine it would be especially difficult to get a clean installation with a spiral wrap. The Scotch 88 is a vinyl tape with a little bit of stretch to it, so it can stretch a bit if your wraps aren't quite perfect and still leave a flat finished surface.


  4. n2dirt | | #5

    Airex makes a nice easy to install product

  5. brian_wiley | | #6

    Eric’s suggestion of the Airex sleeve is a good one. I wasn’t able to use it in my case as I had an oil return bend, and it’s not flexible enough to make tighter bends. It’d be great for straight pipe though.

    I used Pasco pipe wrap and it worked really well.

    1. Expert Member
      BILL WICHERS | | #7

      If you want to spend the time to wrap that with some white Scotch 35 electrical tape, you'll have a cleaner look than the printed black tape. If you can find some good quality stretchy vinyl tape that is white and a few inches wide, it will be easier to install than the 3/4" wide electrical tape, I'm just not aware of any products like that.


      1. user-5946022 | | #8

        Would this stuff work? Would wrapping the insulation with this to begin with be appropriate?

        My linesets are 3/8" and 5/8" OD. The insulation on the 3/8" is very deteriorated. Would this insulation for 1/2" pipe work? There does not seem to be any available for 3/8" or 5/8" od pipe.

        1. Expert Member
          BILL WICHERS | | #9

          That flex tape might work. Ideally you want something a little stretchy though, like electrical tape, so that you can keep it from wrinkling as you apply it. Duct tape is usually reinforced and not stretchy, which would make application more difficult. Duct tape can also delaminate. A single layer vinyl tape would probably be better.


          1. Trevor_Lambert | | #11

            That Flex Tape is quite stretchy; it's nothing like duct tape, despite what the link address implies. I actually have some of the clear stuff. I think the 4" width is excessive, and would make application difficult on anything other than straight pipe. Also pretty pricey.

            I didn't have much luck finding any of the Scotch 88 in wider than 3/4" near me. I found this stuff I might try:

      2. brian_wiley | | #10

        Thanks for the tip on the Scotch 35, Bill. I didn’t know that came in anything but black.

        And I don’t know why I didn’t think of this earlier (and even for my own job) but JM’s Z-Tape should work in this application. I’ve only used 1” indoors, but I looked and it comes in 1.5” and 2” and is rated for exterior use.

        Might be worth a shot unless someone here has had negative experiences with it for this type of application.

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