Interpretation #6940

Published March 08, 2012

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Original Request

Code Version
2007
Code
MECHANIC
Code Description
Mechanical
Chapter
6
Section
607.5.5, Exception #2
Topic
Smoke Dampers

Question

Is it the intent of FMC 607.5.5, Exception #2 to exclude smoke dampers in sprinklered building, of B and R occupancies, as long as 22" boots are used, and a roof exhaust fan at the top of the shaft runs continuously, and is connected to secondary power?

Answer Published 03/08/2012 at 10:45 AM

Yes, If all the requirements of the code section are met
and where all the specific materials and applications are
provided as listed in the exceptions, smoke and fire
dampers may be excluded for kitchen, clothes dryer,
bathroom and toilet room exhaust openings in both B and R
occupancies.

Commentary

an additional requirement of the code section is: "...the exhaust fan at the upper terminus is powered continuously in accordance with the provisions of Section 909.11 of the Florida Building Code, Building, and maintains airflow upward to the outdoors." 909.11 requires a secondary standby power source.