# Janitorial closet exaust.



## chris kennedy (Sep 27, 2011)

I'm looking around in the IBC and IMC for a requirement that exhaust fans run 24/7, is this a design issue, NFPA issue or am I off base?

Thanks.


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## JustReid (Sep 28, 2011)

This is usually related to a sub-duct system where a damper has been eliminated. Not sure if there are other times when they are required to run 24/7. Sorry do not have code sections right now and have to run.


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## mtlogcabin (Sep 28, 2011)

2009 IMC

607.5.5 Shaft enclosures.

Shaft enclosures that are permitted to be penetrated by ducts and air transfer openings shall be protected with approved fire and smoke dampers installed in accordance with their listing.

Exceptions:

1. Fire dampers are not required at penetrations of shafts where:

1.1. Steel exhaust subducts extend at least 22 inches (559 mm) vertically in exhaust shafts provided that there is a continuous airflow upward to the outdoors; or

1.2. Penetrations are tested in accordance with ASTM E 119 or UL 263 as part of the fire-resistance-rated assembly; or

1.3. Ducts are used as part of an approved smoke control system in accordance with Section 909 of the International Building Code, and where the fire damper will interfere with the operation of the smoke control system; or

1.4. The penetrations are in parking garage exhaust or supply shafts that are separated from other building shafts by not less than 2-hour fire-resistance-rated construction.

2. In Group B and R occupancies equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 of the International Building Code , smoke dampers are not required at penetrations of shafts where kitchen, clothes dryer, bathroom and toilet room exhaust openings with steel exhaust subducts, having a minimum thickness of 0.0187 inch (0.4712 mm) (No. 26 gage), extend at least 22 inches (559 mm) vertically and the exhaust fan at the upper terminus is powered continuously in accordance with the provisions of Section 909.11 of the International Building Code , and maintains airflow upward to the outdoors.


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## imhotep (Sep 28, 2011)

chris kennedy said:
			
		

> I'm looking around in the IBC and IMC for a requirement that exhaust fans run 24/7, is this a design issue, NFPA issue or am I off base?Thanks.


2009 IMC



> *401.6 Contaminant sources.* Stationary local sources producing airborne particulates, heat, odors, fumes, spray, vapors, smoke or gases in such quantities as to be irritating or injurious to health shall be provided with an exhaust system in accordance with Chapter 5 or a means of collection and removal of the contaminants. Such exhaust shall discharge directly to an approved location at the exterior of the building.


Here is the closest I can come up with.  Seems like it would be a stretch.  What is the concern?


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## Codegeek (Sep 28, 2011)

Chapter 5 of the IMC does not list exhaust for a janitor's closet as a required system.  If you reference back to Table 403.3 for exhaust rates, there is nothing listed there that would resemble a janitor's closet.

Do you have access to ASHRAE Standards?  You might check there, ASHRAE 62.


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