GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Siting Minisplit Condenser Unit

jenniferz5 | Posted in General Questions on

I had planned to mount my MRCOOL 27k multi-zone condenser unit facing North, on the East side of the house.  After advice stating that I would need to watch for ice in the base pan, I now wonder if it would be better to situate the condenser on the West side of the house, facing South. It will be protected both on the North and East sides by the house; it will also have a Diversitech roof.  The warmth of the sun will only really affect the unit in the late afternoon, but might that be a bonus for preventing ice?  Also, since we only use air conditioning for 3-5 days of the entire year, I can’t imagine we would need to worry about overheating (which seems to be the concern with placing it on the South side of the home).

This placement will also involve longer line set runs, but the MRCOOL allows for 197′ in total, 75′ per line set, plenty of room for my configuration; and, as a bonus, may minimize the vibration noise that so many mention.

Will my plan work?

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. ERIC WHETZEL | | #1

    I have some anecdotal evidence:

    I'm in the Chicago suburbs, and my outdoor unit is on the north side of my house. During the Polar Vortex in early 2019 when temperatures fell below -18º F, it did shut off for a couple of hours.

    A Passive House in Chicago where the outdoor unit sits on a roof with full southern exposure never turned off at any point during the Polar Vortex, presumably because the bright sunshine was giving the unit enough warmth to avoid shutting off.

    1. jenniferz5 | | #4

      Wonderful! Thank you.

  2. walta100 | | #2

    My opinion anything you might and that is a big might gain you will more than lose if double length of the line set.

    I did not see your location how many day are you likely go without getting above freezing? Does MRCOOL offer a pan heater kit for your unit?


    1. jenniferz5 | | #5

      I am in Zone 5a. I am considering running the line set through the basement. Will that help?

      1. charlie_sullivan | | #6

        Running the line set through the basement vs. what alternative? Around the perimeter outside? What length with each plan?

        1. jenniferz5 | | #7

          Yes - 75' (the maximum allowable) around the perimeter vs. 40' through the basement.

    2. bfw577 | | #9

      I was wondering the same. Most of those Mr Cool units don't have basepan heaters and have poor cold performance. I think the cutoff is 5 degrees and they have lost most of their capacity at that temp.

  3. Jon_R | | #3

    Also consider wind exposure. Too much and it is likely to sometimes have problems defrosting.

  4. walta100 | | #8

    I say a shorter line set is a bigger efficiency advantage then the unit’s orientation to the sun or wind. Use the shortest path possible that will not ugly.


Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |