Life Safety Dampers and Damper Testing
When ductwork passes though rated fire or smoke walls, a life safety damper is required in order to maintain the rating of the wall. In the event of a fire, these dampers close and limit the spread of heat and smoke beyond the wall.
There are 3 main types of life safety dampers:
These dampers can be constructed of blades or curtains. They are typically spring loaded, and are held open by a heat-sensitive link. During a fire the link melts, allowing the damper to shut.
These are spring loaded blade dampers accompanied by a smoke sensor. An actuator holds the damper open under normal conditions. In the event the sensor detects smoke or power is lost, the spring closes the damper.
These dampers function in the same way as smoke dampers, except that the damper carries a fire rating, and the installed sensors are able detect heat as well as smoke.
Through IFC and NFPA references, the state of Wisconsin requires fire and smoke dampers to be tested at 3 intervals:
- Acceptance test prior to occupancy
- One year after occupancy
- At the following interval from that point forward:
- Every six years for hospitals
- Every four years for all other occupancies
During these tests, the dampers must be triggered and inspected to ensure all components function properly. In fire dampers, the link must be removed and the damper must close under its own power. For smoke and fire smoke dampers, the actuator must close the damper fully when the sensors are triggered or power is removed. After testing, dampers which pass must be returned to their original condition and dampers which fail must be repaired immediately.
It is important to ensure adequate access to fire and smoke dampers both in terms of damper location within the room, and duct access door sizing. If you have any questions regarding dampers or would like any further information, contact Ahern today!