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

Combustion air requirements

jj1989 | Posted in Building Code Questions on

Without getting into the other air intake possibilities…code requires that the outside air intake ducts be covered with no less than a 1/4″ screen. My concern is that there are a lot of bugs, mold spores, etc. that are much smaller. There’s no way to fit this with a filter?

More details:
I bought a foreclosed house and the bank had just installed a brand new power vent water heater. Unfortunately, as I would like to seal up the house I am worried about providing combustion air to this appliance. A direct vent water heater would have been preferable but I’m not willing to shell out the cash to replace an 8 month old water heater.

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. GBA Editor
    Martin Holladay | | #1

    Jim,
    If I understand correctly, this code-mandated air intake duct leads from the intake grille to a mechanical room or basement. Usually this type of duct terminates near the appliance it serves.

    Unless you have noticed an infestation of insects or indoor air quality problems, I would stop worrying if I were you.

    It may be possible to build a partition to separate your mechanical room from the rest of the house, if you are worried that your indoor air could be contaminated. But you need to be sure that the room meets minimum volume requirements, and that your fresh air duct is adequately sized, or you could further exacerbate the combustion air problem.

    Finally, if you have chemical sensitivity issues, or if you have a particular medical reason why you need all outdoor air to be filtered before it enters the house, you may be happier if you swap the powered-vented water heater with a new sealed-combustion water heater.

Log in or create an account to post an answer.

Community

Recent Questions and Replies

  • |
  • |
  • |
  • |