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Critter damage to mini-split lines. How to protect/prevent?

This is a two year old mini-split installation. Rodentals of some sort have started to chew through the outer coverings. I want to use something to deter/prevent this from happening. As well as the associated wiring. They are only exposed for about 2-3 feet before they go up the line set cover.

I was thinking wire loom, but it's just simple plastic. I suspect they'd chew right through it. The OD is 1 1/4". It's got to be something I can add on without breaking the lines.



  • pecmsg
    pecmsg Member Posts: 4,847
    The insulation is only to prevent condensation form forming and creating water damage. Outside you can cover with anything.

    As far as electrical it should all be in seal tight.
  • mattmia2
    mattmia2 Member Posts: 9,646
    you could also make it so they can't climb on that ledge and chew on it in the first place
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,837
  • Derheatmeister
    Derheatmeister Member Posts: 1,543
    You could use a sonic frequency devise,Wrap it with Steel wool or put a Cat on watch ;) ..Mice do not like either one of these.
  • ratio
    ratio Member Posts: 3,626
    My preference is rapid-onset lead poisoning, but wrapping that portion with metal screen (copper or stainless) will keep the varmints from chewing on it.
  • Paul Wolf
    Paul Wolf Member Posts: 38
    Thanks for the replies and suggestions. I am sure I can figure something out. I just thought (like line set covering) there might have been something made for the exact purpose.

    Also, Pecmsg, the electrical feed for the unit *IS* in seal tight. The wall unit(s) wiring is not. It's exposed for about 2-3 feet then up into the line set covering. Thoughts?

  • PC7060
    PC7060 Member Posts: 1,159
    edited April 2021
    Looks like squirrel damage? I’ve had good luck with NixALite to prevent bird roosting along with discouraging rodent damage. 

    Very pointy stuff so not good option if you will have to routinely work in that area. 
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,294
    edited April 2021
    Hi, Maybe something like this "smurf tube" slit down the side? This is only one inch. Not sure how big it's made.

    Yours, Larry
    JUGHNE Member Posts: 11,061
    Direct burial wires were often chewed by gophers. The solution was DB (direct burial) pipe, SCH 20 thin PVC, or "gopher pipe".
    It protected the wires because it was too large of a diameter that the critters could not get their mouth around the pipe.

    There is "Smurf" tube that it about 2" diameter. Typically is orange and used for UG fiber optics cables.
    Probably plenty of 2-3' scraps thrown away. Not usually split, you would have to cut. A few cable ties would keep it closed.

    I always pack SS wool in the ends of the lineset cover to keep mice out.
  • Intplm.
    Intplm. Member Posts: 1,949
    What I would do in your situation is get some of that spiral black flex pipe you can find in your local garden center. Cut it lengthwise and snap-fit it over the line set bundles. (Sort of like the "same" yellow stuff fitted on the top of little league fences .)
    Then I would use a little spray foam to seal the ends, or just pack the ends with steel wool. Critters don't like steel wool.
    This should do what you need.
  • PC7060
    PC7060 Member Posts: 1,159
    For outside uses,I’ve used the coarser stainless steel scrubby pads versus standard steel wool.  
  • Kybeans403
    Kybeans403 Member Posts: 56
    I use 1/2" smurf tube all the time, especially in historic homes which we've retrofitted with High Velocity systems. The old, old homes seem to always have critters.. They make snap in connectors for the tubing so you can sleeve the low voltage all the way point to point.. It's a minimum cost to eat so we don't have to come out and find a short somewhere in comm wire to condenser that was chewed.

    **they also make UV resistant duct tape to repair damage like that **

    Also used:
    - dryer sheets 
    - moth balls
    - scotch Brite pads in any holes to units 
  • SlamDunk
    SlamDunk Member Posts: 1,580
    My coworker had squirrels chew up an engine wire harness in his F-250. He came to find out that Ford started using soy base wire insulation and it attracts rodents. Maybe something similar is going on here?
  • clammy
    clammy Member Posts: 3,111
    I ve seen this happen on a mini split I installed what type of rodent is unknown but we re insulated and though nothing about it till it happened again we then covered w regular metal foil tape and it’s been fine now for about 10 years . I guess wrapping it w the foil tape was the cure . As for inter connecting wiring we switched years ago to the rubber coated bx wire being according to codes the Honeywell stranded rubber is not to code to run through a building weather residential or commercial it can only be used if you run directly into the unit say from your lineset penetration into the unit . Inspector stated rodent issue sort of like nyc and no Romex . As another note we stopped using the line sets w white insulation it seems the supply house no longer carry them wonder why but it have noticed all the lineset say 10 year warranty what a great out for leaks lol peace and good luck clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
    EBEBRATT-Ed Member Posts: 15,525
    edited April 2021
    TC Cable (Tray Cable) is not approved for wiring (generally) unless it is in a raceway (EMT, Conduit, Greenfield ETC.)

    It is not approved exposed without a raceway on any commercial job. It can be used exposed indoors without a raceway only in one and two family dwellings. It's used for generator hook ups and ductless splits

    NEC Code 336.10