Corridor air movement question/conflict

[Sifu]

Given a corridor in an R2, a small laundry room with a single dryer opens directly to the corridor with a door with a louver to provide makeup air for the dryer.

IMC 601.2 & IBC 1020.5 prohibits a corridor from acting as makeup air, but excepts small rooms (a laundry room is not specifically listed but would seem to meet the intent of the section) that opens directly to the corridor as long as the OA system of the corridor exceeds the volume of the makeup air being drawn from the corridor, creating a positive pressure in the corridor so that smoke won't be drawn into the corridor. IBC 716.2.2.1.1 does not allow louvers in door assemblies for corridor doors when required to be smoke and draft control door assemblies. Is this a conflict in the codes, or a conflict of my understanding of them?

 

[Sifu]

Or....do they not conflict? Does this mean the corridor can supply the makeup air, but not through a door with a louver in it? So a transfer grill from the corridor is acceptable but a louvered door is not? In a sprinklered building a fire damper could be omitted from the transfer grill if protected as a through penetration but then the transfer opening would require a smoke damper per 717.5.4.1?

 

[klarenbeek]

It's not a conflict. Makeup air can come from the corridor, it just has to be through a transfer duct with the wall penetration protected as you said with a damper. It can't be through a louvered door.

 

[Yikes]

In NFPA 80, a fire rated door can have an undercut up to 3/4" and not lose its fire rating. But the volume of air required for a clothes dryer may exceed what can be provided by an undercut that size.

 

[Yikes]

IMC 601.2 & IBC 1020.5 prohibits a corridor from acting as makeup air, but excepts small rooms

I think you meant IBC 1020.6 (in the more recent editions).

 

[Sifu]

I didn't specify but I was referencing the 2018 for this one, but yes, they moved it.

 

[Paul Sweet]

IBC 716.2.2.1.1 limits the air leakage of fire-rated doors in corridors and smoke barriers and prohibits louvers. The air leakage limit might rule out undercuts,

 

[Yikes]

IBC 716.2.2.1.1 limits the air leakage of fire-rated doors in corridors and smoke barriers and prohibits louvers. The air leakage limit might rule out undercuts,

I see your point, but the leakage tests themselves allow the tester to additionally seal the bottom 6" of the door opening as part of the test procedure. In other words, the door threshold and its NFPA 80 allowable undercut ("clearance at the bottom of the door") are irrelevant to the air leakage performance test.

From UL:
"Artificial bottom seals – UL 1784 allows for an artificial seal to be applied to the bottom 6 inches of the test sample in order to obtain information on the extent of air leakage through the perimeter of a test sample without the sample leakage being influenced by the clearance at the bottom of the door. The artificial seal may be any material, such as an impermeable plastic sheet or tape. The manufacturer chooses whether an artificial bottom seal is applied or not during the test."

https://code-authorities.ul.com/ul-...=The air leakage rate of,400°F) exposure test.