GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter X 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

Recommendations for minisplit? Climate Zone 6 report included

brandons | Posted in Mechanicals on

This is a follow up on an earlier post. I have attached the engineer’s report I received along with plans. What I don’t know is what the ideal location for heads and zones on the mini split should be. Any recommendations?

The report shows a furnace but please disregard we are trying to use a mini split. We are also using an hrv for the ventilation.

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. brandons | | #1

    Report and plans

  2. user-1137156 | | #2

    First off you have a serious air leakage problem! 3.93ACH@50pa is terrible! getting that down to an acceptable 1ACH@50pa knocks about 7500BTU/h off you load so a 3 ton multisplit will work.

  3. Expert Member
    Dana Dorsett | | #3

    I'll have to disagree with Jerry, ~4ACH/50 isn't really "terrible", especially if it's a retrofit situation. It's pretty crummy for new construction though, failing the IRC code requirement of 3 ACH/50 maximum. It's definitely worth working on, fixing what you can, but not worth tearing the house apart or gutting walls.

  4. brandons | | #4

    Thank you for catching that. I am disappointed in that number as I carefully detailed our air seal approach prior to the design. Zip sheathing for walls, roof, and "bonus" room floor. Poly ceiling barrier. We used the minimum operational windows necessary but they are casements. I'm confident we will be under 1 ACH50

    Edit: These are based on the prints not an actual blower door test. For now we are trying to identify the equipment, placement, and if it necessitates any changes.


Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |