Is this venting necessary?

[sfalvey]

Todays inspection was on a 23 year old condo.

Both the gas hot water heater and boiler are in separate closets on the 2nd floor. Both closets have a short metal vent in the ceiling (assuming to let warm air out (to the attic)) and combustion air in from the attic.

Are these necessary? What are the draw backs and general comments.

It doesn't sit right with me, but I can't put my finger on it.

Also check out the flue pipe job.

[Colin Cutler]

Scott, my take on the vent pipes in the attic is, there's more free air available in the attic than in perhaps a closed closet. but the horizontal flue looks kinda long.

[Charley L. Bottger]

That is the way we draw combustion air from attic here in this state all the time almost on every one The short pipe is suppose to be into the closet at least 12 inches and the longer pipe is suppose to be 12 inches from the floor creates a natural circulation.

[lfoster]

On pic 5, what about the piping that doesn't reach the ceiling vent opening?

[Mark Thorman]

Linda, that looks like an opitcal conclusion. I think there are two holes there with the one pipe (against the wall) extending toward the floor.

[William J. Decker]

Originally Posted by cbottger

That is the way we draw combustion air from attic here in this state all the time almost on every one The short pipe is suppose to be into the closet at least 12 inches and the longer pipe is suppose to be 12 inches from the floor creates a natural circulation.

Combustion air cannot be drawn from the attic. The attic is ventilated to allow air outflow. The attic is under negative pressure, therefore. Stack effect.

[sfalvey]

Originally Posted by Mark Thorman

Linda, that looks like an opitcal conclusion. I think there are two holes there with the one pipe (against the wall) extending toward the floor.

That is correct.

[Brian E. Kelly]

Originally Posted by wdecker

Combustion air cannot be drawn from the attic. The attic is ventilated to allow air outflow. The attic is under negative pressure, therefore. Stack effect.

03 IRC allows attic combustion air. 1703.2

[David A. Andersen]

Attic air here too.

[Larry D. Kage]

Originally Posted by wdecker

Combustion air cannot be drawn from the attic. The attic is ventilated to allow air outflow. The attic is under negative pressure, therefore. Stack effect.

It is allowed around here, too, Will.

[Charley L. Bottger]

Originally Posted by wdecker

Combustion air cannot be drawn from the attic. The attic is ventilated to allow air outflow. The attic is under negative pressure, therefore. Stack effect.

What, Two million homes in Ok improperly vented for combustion air

[msylvester]

It's OK here in Illinois as well.

[Charley L. Bottger]

Originally Posted by msylvester

It's OK here in Illinois as well.

Mark Chicago is not in Illinois right
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[msylvester]

nowhere near Illinois.

[William J. Decker]

I stand corrected by my peers.

I was always taught that getting combustion air from the attic was wrong, mainly because of the stack effect and that the attic tends to craw air out.

Must have been wrong.

Sorry.