Do you just need a fire damper or a combination fire smoke damper?

 

 You need just a fire damper when the barrier (wall, floor) is only a fire separation.  You need a combination fire-smoke damper when the barrier is both a fire and a smoke separation.  Who decides the nature of the barrier?  An architect or the City.
An actuator-driven damper gives you the flexibility to quickly bring back the damper to its normal (open position).
    The combination fire-smoke damper is actuated two different ways:
1.    Fire.  In case of a fire event, the high temperature is sensed by the sensor associated with the damper; a contact gets open, power to the actuator is cut off; the damper is closed.
2.    Smoke.  There is normally no smoke sensor being an integral part of the combination fire-smoke damper.  The signal of smoke detection must come from an external source (a duct-mounted smoke detector or a fire alarm panel).  The external signal is fed into the electronics of the damper.  When a signal is received, a contact gets open, power to the actuator is cut off; the damper is closed.

You don’t need a duct mounted combination fire-smoke damper in a fire-smoke separation barrier when the air moving system has a capacity of over 2000 CFM since such an air moving system is already required to have an automatic shut off based on smoke detection at the equipment level.

CAMC 608.1
“Air-moving systems supplying air in excess of 2,000 cubic feet per minute (944 L/s) to enclosed spaces within buildings shall be equipped with an automatic shutoff.  Automatic shutoff shall be accomplished by interrupting the power source of the air-moving equipment upon detection of smoke in the main supply-air duct served by such equipment.  Smoke detectors shall be labeled by an approved agency approved and listed by California State Fire Marshal for air duct installation and shall be installed in accordance with the manufacturer's approved installation instructions.....Where fire detection or alarm systems are provided for the building, the smoke detectors required by this section shall be supervised by such systems and installed in accordance with NFPA 72 and the California Building and Fire Codes.”

Photo courtesy of Ruskin

Tags: How does a combination fire-smoke damper operate?

Is there a smoke sensor in the combination fire-smoke damper?

A combination fire-smoke damper operated by a smoke detector.

A combination fire-smoke damper operated by a fire alarm panel.