Common questions

What is the difference between a smoke damper and an air damper?


What is the difference between a smoke damper and an air damper?

Knowledge of these differences is imperative to the proper application of the dampers and their performance in the life/safety system. A fire damper closes once the duct temperature reaches a high enough level to melt a fusible link. A smoke damper closes upon the detection of smoke.

Are HVAC dampers required?

Smoke dampers are required in HVAC systems with a capacity greater than 15,000 cfm in order to isolate the AHU from duct distribution. Duct-mounted smoke detectors, however, are not required in a return air system if the spaces served by the HVAC system are protected by ceiling-mounted smoke detectors.

How are smoke dampers rated?

Fire/smoke dampers are typically rated for 1-1⁄2 or 3 hours fire resistance. A 1-1⁄2 hour rated damper is sufficient for walls or floors having a rating of less than 3 hours. If the wall or floor has a rating of 3 hours or more, a 3 hour rated damper is required for sufficient protection.

What is FSD damper?

The FSD-331 is a combination fire smoke damper with airfoil blades. This model is rated for use in walls, floors, or partitions with a fire resistance rating of 3 hours or more and a Class I leakage rating.

How do I know if my damper is open or closed?

Before lighting a fire, you can tell if the damper is open by placing your hand into the fireplace. If you feel a draft coming down the chimney, it is a good indicator that the damper is open. If you don’t feel any cold air coming down the chimney, it means that the damper is closed.

Should fire dampers be open or closed?

The fireplace damper should always be in the open position whenever you have a fire in the fireplace. Never close the damper or leave the fireplace unattended while there is a fire in the fireplace. This is not only a fire hazard, it can also cause deadly carbon monoxide poisoning.

Where are smoke dampers located?

Location: Fire dampers are installed in or near the wall or floor, at the point of duct penetration, to retain the integrity and fire rating of a wall or floor whether it is a ducted or open-ple- num return application.

Do fire dampers need to be monitored?

Damper Control – Active When part of a smoke control system, Dampers must be monitored for position and fault. Two fire alarm relays are required to force closed and force on.