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

ERV duct sizing for residential house

ken_o | Posted in Mechanicals on

I think I’ve read most everything I can find online, and yet, I’m still puzzled.  I’ve read Alison Bailes ductwork guides, and I think I understand TESP, ASP, TEL, FR, etc.  The ERV that sounds right for my house (still in planning) is a Lifebreath 130 ERVD. Ductwork will all be within the heated envelope.

If I follow Alison Bailes design methods (which really only seem to reference heating and cooling systems, but I assume they would also apply to dedicated ERV ductwork), I come up with a 6.5″ round or 3.5″ x 12″ rectangular trunk.  Most ERV/HRV diagrams show ductwork no bigger than the ports on the ERV/HRV unit.  Is a bigger trunk size unusual, or did I miscalculate or misinterpret something?  

Thanks for your thoughts.

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.

Replies

  1. Expert Member
    Akos | | #1

    This is not uncommon. When you end up with longer/complicated main trunk, you end up needing to upsize to stay within the pressure loss limits. You can sometimes re-design your ducting to avoid this by making some of your supply lines longer instead of the extra long main trunk.

    Put a reducer right at the unit and run the larger ducts.

  2. ken_o | | #2

    Thanks. That's the "vote of confidence" I needed. The ducts will fit OK, I just didn't want to pay for the bigger ducts if I didn't need them.

Log in or create an account to post an answer.

Community

Recent Questions and Replies

  • |
  • |
  • |
  • |