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

Air intake for ERV

bsawers | Posted in Mechanicals on

Asking again about an ERV installed incorrectly during a renovation before I bought this house. Currently, the ERV connects to the air handler, but both the air intake and exhaust are located inside the attic.

I have exhausted all the local HVAC companies claiming ERV/HRV expertise. One company claimed an intake inside the attic was fine because it was close to a turbine roof vent. The other company sent an apparently knowledgeable technician who said he would get back to me with solutions, but refuses to return my calls now.

One option is running a long pipe to the eave vents to draw in fresh air. The other option is a short pipe through the roof. If the ERV is only used in the winter, how much off-gassing from the shingles happens?

Our windows are open in the spring and fall, so there’s a gap between heating and cooling and I will remember to climb into the attic and turn the ERV off. That’s another “mistake” since there’s no controls for the ERV from inside the house, just the attic.

I do not like putting another hole in my roof, but the alternative is 30 feet and a very constrained eave vent since the eave itself is only 4 inches wide.

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. matthew25 | | #1

    Is this an airtight house? Do you need an ERV at all? Do you have bath fans you can use instead?

  2. bsawers | | #2

    The house is airtight enough that an ERV is needed on the top floor. We had a blower door test, which indicated a probable need. But we notice the difference during the heating season when windows are never opened.

  3. freyr_design | | #3

    You could find a place to locate a bulkhead/chase and just exit it through a wall. Maybe your kitchen cabinets don’t go to the ceiling and you could build a bulkhead above, or somewhere else.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |