Shaft penetration

[Codegeek]

I have a project which involves a shaft penetrating at least three floors for an R use group. This shaft is being utilized for bathroom exhaust ventilation which meet the subduct requirements of 716.5.3 (2006 IBC).

My problem is that I say that the fire and smoke dampers can be eliminated if the shaft meets ALL of the requirements, which I read to include an exhaust fan at the top of the shaft which operates continuously as well as being provided with two sources of power.

I’m having problems convincing the client that this is a code related requirement. I’m being told that by both the client and a codes expert this is the first they’ve had to do this and that smoke protection is not required for a shaft enclosure.

Other thoughts?

 

[RLGA]

It's not a smoke control system per Section 909, which is what they seem to be stuck on.

What it is is a continuously exhausted ventilation system, and you're correct, Exception 2 to Section 716.5.3 would be acceptable if all conditions are met.

 

[Coug Dad]

It actually is smoke control since the normally required smoke damper is allowed to be eliminated if specific conditions are met. The cross reference to Chapter 9 then requires a secondary power supply. That does not automatically require a generator if other reliable sources are available.

 

[Codegeek]

Thank you both for your responses. I tried to explain that this did not have to meet the provisions for smoke control, only meet the requirements to meet the exceptions permitted for the shaft penetration protection. I tried to explain that if there is no backup power, then the fan will not operate and the smoke will migrate back into the building under fire conditions, which defeats the whole purpose to the exception!

 

[brudgers]

Providing a continuous fan is going to be hell on energy efficiency - not so much for fan power as for the effect of all that makeup air on heating and cooling loads.