# Laundry room makeup air via corridor?



## Yikes (Nov 6, 2015)

Small laundry room (with gas dryers) in fully sprinklered building that is next to an corridor that is open to the outside at both ends.

CBC 1018.5 exception #1 allows the corridor to be used as a "source of makeup air for exhaust systems" in adjacent rooms, including toilet and dressing rooms, janitor closets, etc.  It is silent on laundry rooms, so it is neither inclusionary nor exclusionary of them.

Our laundry room has gas dryers, which means the makeup air is simultaneously being used for an exhaust system (the dryer moist air exhaust) and also for combustion (the dryer heat), all in the same process.

Would you allow this laundry to pull air from the open-air corridor?  Are low+ high vents required?  Is there anything that would compel a fire- or smoke/fire damper?


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## north star (Nov 6, 2015)

*@ | @ | @*

Is the corridor rated ?

Here's the code section:

*`13 CBC, Section 1018.5 - Air movement in corridors:*

Corridors shall not serve as a supply, return, exhaust, relief or

ventilation air duct:

*Exceptions:*

*1.*  Use of a corridor as a source of makeup air for exhaust systems in

rooms that open directly onto such corridor;  including toilet rooms,

bathrooms,  dressing rooms, and janitor closets,  shall be permitted

provided that each such corridor is directly supplied with outdoor air

at a rate greater than the rate of makeup air taken from the corridor.

*@ | @ | @*


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## Yikes (Nov 6, 2015)

north star said:
			
		

> *@ | @ | @*Is the corridor rated ?
> 
> Here's the code section:
> 
> ...


Yes, that is correct.  I just wanted to make sure that there would not be a problem if the air is being used for two simultaneous purposes (exhaust makeup AND combustion) by the  same device (the gas dryer).


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## Yikes (Nov 6, 2015)

And yes, the corridor is one-hour rated.  It is a new apartment building.


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## cda (Nov 6, 2015)

""""Would you allow this laundry to pull air from the open-air corridor? Are low+ high vents required? Is there anything that would compel a fire- or smoke/fire damper?"""

If you are penetrating the rated wall!


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## Yikes (Nov 6, 2015)

cda, good point... just because I am allowed use of makeup air form the corridor does not mitigate the need for dampers per 717.5.4.1.

Thanks for snapping me back to reality.


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## ICE (Nov 6, 2015)

Yikes said:
			
		

> And yes, the corridor is one-hour rated.  It is a new apartment building.


The architect is responsible for this.


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## cda (Nov 6, 2015)

Yikes said:
			
		

> cda, good point... just because I am allowed use of makeup air form the corridor does not mitigate the need for dampers per 717.5.4.1.Thanks for snapping me back to reality.


It is Friday, time to dump all code knowledge


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## ADAguy (Nov 10, 2015)

If, as you previously stated, this is a new apartment building, then how did the architect design the laundry rooms to vent if dryers are gas?


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## Yikes (Nov 10, 2015)

ADAguy said:
			
		

> If, as you previously stated, this is a new apartment building, then how did the architect design the laundry rooms to vent if dryers are gas?


Laundry room was designed to vent to the exterior.  There's just not enough wall space to correctly separate the exhaust from the intake.

Intake supply can be brought down from the roof, but the question was asked if it could come from the corridor instead to avoid shaft construction.


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