Interpretation #7539
Published July 20, 2015
Original Request
- Code Version
- 2010
- Code
- MECHANIC
- Code Description
- Mechanical
- Chapter
- 5
- Section
- 513.6
- Topic
- Smoke removal
Question
Is it the intent of FBC 2010 Mechanical 513.6, Pressurization method, to have the floor of fire origin, exhaust or remove smoke ? The last sentence of the Code section indicates " Maintenance of a tenable environment is not required in the smoke control zone of fire origin. ".
Answer Published 07/20/2015 at 12:19 PM
No, it is not the intent of this section to require exhaust.
Commentary
The intent is to prevent the spread of smoke to other floors
or exit paths by keeping the smoke in the zone of origin
through pressure "differences". This may result from
exhausting the space lower than surrounding spaces or
increasing pressures in surrounding spaces. If the space is
exhausted at the same time surrounding areas are
pressurized, it is easy to exceed the maximum allowable door
opening/closing forces per 513.6.2. So long as that force is
not exceeded, internal exhaust and external pressurization
could be combined.