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

ERV install questions- dryer periscopes, return air grilles, and flex duct

brandons | Posted in General Questions on

I am installing the Renewaire EV200 to run continuous as a dedicated ducted system.  The home has 6 bedrooms and 4 bathrooms.  

-Any issues with using dryer periscopes for the fresh air supply to the bedrooms?  The periscope would stub into the joist cavity and up into the 2×4 wall about 24” high for the fresh air supply register.  The install requires two 90 degree transitions per room, then straight to the plenum.  The periscope appears to simplify things. 

-Is flex duct still recommended for at least 6’ from the registers to reduce noise?

-Are the round adjustable air grilles by Fantech etc sufficient for balancing the airflow and use in the bathroom return air locations?

Thank you, 

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

    I haven't tried these, I would guess they will be fine on low flow, but could be loud when the unit is on boost.

    You generally don't want to hear the unit ramping up in a bedroom at all, this is partly why there is the recommendation of larger ducting plus the length of flex. A length of flex between the ERV supply and the main supply trunk also helps. You can try to mock up one of these and see how loud it is.

    A 5" oval hard pipe with an oval round 90° boot on the bottom and oval stackhead on the top can work inside a 2x4 wall. The simpler option is to bump up the framing depth slightly there and run 4" flex to a 3x10 boot.

    Flow control is always best set with a damper. These are not something you should need to adjust after commissioning.

Log in or create an account to post an answer.

Community

Recent Questions and Replies

  • |
  • |
  • |
  • |