GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Audio Play Icon Headphones Icon Plus Icon Minus Icon Check Icon Print Icon Picture icon Single Arrow Icon Double Arrow Icon Hamburger Icon TV Icon Close Icon Sorted Hamburger/Search Icon

Community and Q&A

Power vent water heater is backfeeding cold air

Mid michigan | Posted in Mechanicals on

Hi guys, We here in Michigan just got over a single digit 11 day cold spell. This is where you really can test your basement for cold air leaks. Speaking of that, I waked by my water tank and was pretty much blown back by a wave of cold air. So when the fan kicks on it pulls air from the basement to vent the gas out the rim joist through 2″ pvc tube. Ok, that’s great. Now when the fan is not blowing the pvc is just letting the cold outside air to backfeed right through the fan intake into the basement. I guess it would need a spring loaded flapper or something on the end of that pipe outside to block it off when fan is not running. Sadly I cant find any application for this. Any ideas, thanks

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. User avatar GBA Editor
    Martin Holladay | | #1

    Mid Michigan,
    Either your house is depressurized (due to the operation of bathroom exhaust fans, the range hood fan, or the clothes dryer), or you have big leaks in your top-floor ceiling (the attic floor).

    If you seal the attic leaks, you will reduce the stack effect (and reduce the entry of cold air into your basement). Here is a link to an article that describes the necessary work: Air Sealing an Attic.

    Concerning exhaust fans, there's not much you can do about the bath fans and the clothes dryer -- but if you have a big range hood fan, you should read this article: Makeup Air for Range Hoods.

  2. Tom May | | #2

    2 X 4 pvc coupling....4" dryer vent outside.....done

Log in or create an account to post an answer.

Community

Recent Questions and Replies

  • |
  • |
  • |
  • |