Combination Fire/Smoke dampers meeting or exceeding the following specifications shall be furnished and installed at locations shown on plans or as described in schedules. Dampers shall meet the requirements of NFPA90A, 92A, and 92B and shall be Class II leakage rated dampers for use in smoke control systems and 1 to 1/2 hour fire rating in accordance with the latest version of UL555S.
As part of the UL qualification, fire/smoke dampers shall have demonstrated a capacity to open and close under HVAC system operating conditions, with pressures up to 4 inches w.c. in the closed position and 2000 fpm air velocity in the open position.
In addition to the leakage ratings already specified herein, the dampers and their actuators shall be qualified under UL555S to an elevated temperature of 250°F (121°C) or 350°F (177°C) depending upon the actuator. Appropriate pneumatic or electric actuators (specifier selects one) shall be installed by the damper manufacturer at the time of damper fabrication. Damper and actuator shall be supplied as a single entity which meets all applicable UL555S qualifications for both dampers and actuators. Each damper shall be rated for leakage and airflow in either direction through the damper. Damper and actuator assembly shall be factory cycled at least 10 times to assure operation.