Toilet exhaust duct-Multi Family

[joecode]

50 CFM ceiling exhaust fan-4" duct in a wood framed-1 hr rated ceiling: What are people here doing to protect the penetration of the membrane?

It seems to me a Fire Damper at the fan is required or encase the fan and duct all the way to the exterior with FR gyp bd. Any exceptions? the AHJ
does not know at the moment....

All ducts are within the units, go horizontally directly to the exterior wall, and do not penetrate any fire partitions. The runs are under 20'
Project is in NY state- 2020 code which is 2018 IBC.

Thank you all

 

[mtlogcabin]

Usually the fire rating is above the exhaust fan which is installed in a lower non-rated ceiling. The duct work runs below the rated floor ceiling assembly in a soffit.
Or the exhaust fan is installed in the non rated wall and the metal duct is installed within the rated assembly.

 

[Jay Smith]

This one has a built-in damper and shows the UL assemblies in which it works.

 

[joecode]

Usually the fire rating is above the exhaust fan which is installed in a lower non-rated ceiling. The duct work runs below the rated floor ceiling assembly in a soffit.
Or the exhaust fan is installed in the non rated wall and the metal duct is installed within the rated assembly.

Yes i do have some soffits for interior units. Fan in the wall is something I have not thought of- thanks.