717.5.2 Fire barriers.
BC § 717.5.2
Ducts and air transfer openings that penetrate fire barriers (horizontal and wall assemblies) shall be protected with listed fire dampers installed in accordance with their listing. Ducts and air transfer openings shall not penetrate enclosures for interior exit stairways and ramps and exit passageways, except as permitted by Sections 1023.5 and 1024.6, respectively. In addition, smoke dampers shall be installed in penetrations of public corridor and horizontal exit walls in accordance with Sections 717.5.2.1 and 717.5.2.2. Exception: Fire dampers are not required at penetrations of fire barriers where any of the following apply: 1. Penetrations are tested in accordance with ASTM E 119 or UL 263 as part of the fire-resistance-rated assembly.
2.Ducts are used as part of an engineered smoke control system in accordance with Sections 717.2.1 and 909 of this code where the use of a fire damper would interfere with the operation of a smoke control system.
3.Such walls are penetrated by ducted HVAC systems, have a required fire-resistance rating of 1 hour or less, are in areas of other than Group H and are in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or Section 903.3.1.2 of this code. For the purposes of this exception, a ducted HVAC system shall be a duct system for conveying supply, return or exhaust air as part of the structure's HVAC system. Such a duct system shall be constructed of sheet steel not less than No. 26 gage thickness and shall be continuous from the air-handling appliance or equipment to the air outlet and inlet terminals.
