0 Helpful?

Combustion air requirements

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.

Asked by Jim Johnston
Posted Aug 1, 2014 2:15 AM ET
Edited Aug 1, 2014 6:12 AM ET

Tags:

1 Answer

Select your preferred way to display the comments and click "Save settings" to activate your changes.
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.

Answered by Martin Holladay
Posted Aug 1, 2014 6:10 AM ET

Other Questions in Building Code Questions

Climate Zone suggestion

In General questions | Asked by Edgar Pankey | Mar 27, 17

Hydronic Heating System Hydraulic Buffer Tank vs Hydraulic Seperator

In Mechanicals | Asked by Roger Smith | Feb 26, 17

Second generation Whirlpool heat-pump clothes dryers: Any good?

In Green products and materials | Asked by John Ranson | Mar 26, 17

adding exterior insulation over stucco

In Energy efficiency and durability | Asked by Christopher Houston | Mar 27, 17

Spay foam on the inside of poured foundation to avoid mold?

In General questions | Asked by jim sweazey | Mar 26, 17
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!