717.5.2.2 Public corridors.
BC § 717.5.2.2
A listed smoke damper designed to resist the passage of smoke shall be provided at each point a duct or air transfer opening penetrates a public corridor wall or floor constructed as a fire barrier. Exceptions: 1. Smoke dampers are not required where the building is equipped throughout with an engineered smoke control system in accordance with Section 909, and smoke dampers are not necessary for the operation and control of the system.
2.Smoke dampers are not required in corridor penetrations where the duct is constructed of steel not less than 0.019-inch (0.48 mm) in thickness and there are no openings serving the corridor.
3.Smoke dampers are not required in corridor penetrations in Group R-2 buildings and Public Corridors serving R-2 spaces in mixed use buildings.
4.Smoke dampers shall not be required in ducts where the air continues to move and the air-handling system installed is arranged to prevent recirculation of exhaust or return air under fire emergency conditions. The air-handling system shall be continuously monitored to ensure continuous airflow at a constantly attended location and be inspected and maintained in accordance with the system manufacturer's instructions.
