607.5.2 Fire barriers.
MC § 607.5.2
Ducts and air transfer openings that penetrate fire barriers 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, of the New York City Building Code. In addition, smoke dampers shall be installed in penetrations of public corridor and horizontal exit walls in accordance with Section 607.5.2.1. Exceptions: 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 Section 513 of this Code and Section 909 of the New York City Building Code and where the fire damper would interfere with the operation of the 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 other than Group H and are in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 of the New York City Building Code. For the purposes of this exception, a ducted HVAC system shall be a duct system for the structure's HVAC system. Such a duct system shall be constructed of sheet metal not less than 26 gage (0.0217 inch) (0.55 mm) thickness and shall be continuous from the air-handling appliance or equipment to the air outlet and inlet terminals.
