Duct Shaft Wall

[cme]

I have a 6 story healthcare building. Each air handler (2 total) is around 140,000 cfm.

What type of construction is permissable for the supply and return shafts?

How are the takeoffs for each floor sealed at the shaft?

Leakage testing advised?

 

[trashcanman]

The duct shaft must be a minimum of 1-hr rated (maybe 2 - check bldg. code). Ducts penetrating the shaft must have fire/smoke damper to maintain the rating of the shaft penetrated.

Always test for leaks.

Good luck

 

[cme]

anybody have experience with this size cfm and duct shaft construction?

 

[cjw81]

In NYC it calls for a two hour rating wiht fire /smoke damper. Also check to see if you need to install plastic breakaway nuts and bolts in the event the duct separates from the damper assembly, the force will not pull the fire damper out of position. Dampers must meet fire smoke ratings as per local juristiction, in the healthcare setting, it must also meet State DOH code specifications.
You must also have duct smoke detectors in certain locations.