Smoke Control in Existing Buildings

[odelgado]

Hello, I have a question regarding smoke management. I have an 11 story medical offices building with a big atrium right in the middle. The original mechanical plans date from 1980 and had a smoke control system that was never installed. The building executive board wants to install the system now. The original system does not comply with today's codes in terms of required cfms. My question is, since the board is installing these fans mostly for peace of mind since tha AHJ is not requiring it and the building is not being renovated, can they install the fans as per the 1980's plans or does this qualifies as a level 2 alteration according to the IEBC and a new design (or at least the Chapter 13 Compliance Method) must be performed? Thanks for any light you can shed on this issue.

 

[pipesnpumps]

11 story and it is just medical offices with all the 'patients' capable of self preservation? Wow that is a large medical office.

I am assuming you are a contractor based on the wording of your question. I would say anything new must be inspected and permitted. I am almost certain an AHJ would not allow a 30 year old design to be used.. If i were you i wouldn't proceed until I had 1) letter from AHJ saying they agree that the original plans may be used even though this does not conform to modern standards. And 2) a signed statement from the building owner stating they are aware that the original design is based on old standards and that building to these would not meet modern versions of similar standards, etc and they accept all risk etc etc (lawyer it up).

If you are an engineering firm just explain why this is a bad idea and offer to redesign to current applicable codes and standards.

As in all situations ask yourself how a jury of housewives and the like would view things if there were to be a death; Not too favorably on using a 30 yr old design drawing.

Real world knowledge doesn't fall out of the sky on a parachute, but rather is gained in small increments during moments of panic or curiosity.

 

[cdafd]

if you permit it through the ahj, looks like they would require meet present code, give them a call

 

[stookeyfpe]

You want to perpetuate a mistake. I will assume the building is located West of the Mississippi and on or near the Pacific Ocean and your client wants an approved smoke control system under the legacy Uniform Building Code.

6 ACH in atrium is what is prescribed. And I'll bet the building is partially sprinklered.

Good luck with that.

 

[odelgado]

Thanks,

I'm not the contractor, I'm just trying to convince the executive board (to deaf ears I might add) that they HAVE to update the smoke control design.

 

[cdafd]

Drag the CEO or whatever down to the ahj, and have a set down meeting with them, since hopefully it will be permitted

And let the ahj tell you and the CEO what will be required

 

[EGFPE]

I have a similar situation with a seven story office building where the fire alarm system was replaced but no one noted how the smoke control system was to operate. The building was constructed prior to the end of the 1980's so I too suspect it is based on 6 air changes per hour. According to a operating matrix found by the building engineer, operation of any detector or water flow device will cause the exhaust and supply dampers to close on the fire floor, and start all the building supply and exhaust fans for the remainder of the building including the stairs and stair vestibules. Basically negative pressure on the fire floor and positive pressure on the other floors. That is basically the method used in the early smoke control systems.