BCAB #1532 - Smoke Detectors in Air Handling Systems, Sentence 22.214.171.124.(1)
March 22, 2001
Re: Smoke Detectors in Air Handling Systems, Sentence 126.96.36.199.(1)
The subject building is a 4 storey sprinklered noncombustible building with residential and institutional occupancies. The building incorporates a common system for bathroom exhaust that complies with Sentences 188.8.131.52.(1) and 184.108.40.206.(1) and serves suites located on different storeys. A fan at the roof level maintains a negative pressure within the main exhaust riser.
Reason for Appeal
Sentence 220.127.116.11.(1) requires that an air handling system to be designed to prevent the circulation of smoke upon a signal from a duct-type smoke detector if the air handling system serves more than one storey.
The appellant contends the exhaust system being under a constant negative pressure inherently prevents the migration of smoke, by exhausting the smoke to the exterior.
Building Official's Position
The Building Official maintains that Sentence 18.104.22.168.(1) requires a duct-type smoke detector be installed in the main exhaust riser to shut down the exhaust fan in the event of smoke in the riser.
Appeal Board Decision #1532
It is the determination of the Board that for the purposes of Sentence 22.214.171.124.(1) a common exhaust system used for bathroom exhaust is not considered an air handling system as defined in common construction dictionaries. A duct-type smoke detector is therefore not required.
George Humphrey, Chair