Smoke control is a proven technology that saves lives.  Smoke or combination fire/smoke dampers and the devices that control them, such as smoke detectors, are important components of a smoke control system.

It is important to understand that smoke dampers do not inherently detect the presence of smoke.  It is a corresponding smoke detector that normally causes the damper to close and thus "stop" smoke from leaking through the damper.

UL555S, the UL Smoke Damper Test Standard, recognizes three different leakage classes.  Smoke or combination fire/smoke are tested and rated according to one of the following classes:

  • Class 1 leakage is 4 cfm/sqft at 1” w.g. or less
  • Class 2 leakage is a maximum of 10 cfm/sqft at 1” w.g.
  • Class 3 leakage is a maximum of 40 cfm/sqft at 1” w.g.

The volume of air leaking through a closed damper represents smoke "leaking" through the damper during a fire.  In life safety situations it makes good engineering sense to specify and install minimum Class 2 smoke or combination fire/smoke dampers.

The New 2000 International Building Code & 1997 Uniform Building Code state the minimum requirements for smoke rated damper actuation methods.  The requirements are found in Chapter 7 of the respective codes.  The code states "that smoke and combination fire/smoke dampers shall close upon actuation of a listed smoke detector or detectors installed in accordance with one of five methods."  The five methods have for the first time within the building codes set out specific requirements.  The Ruskin smoke detector engineering report explains the five methods in detail.  One of the five methods of smoke detection is to install a smoke detector within 5 feet of the damper with no outlets or inlets between the detector and the damper. 

Ruskin provides the solution to installing a detector within 5 feet by offering two types of factory mounted and wired smoke detectors.  The DSDF flow rated duct smoke detector or DSDN no-flow rated duct smoke detector.  The DSDF is our standard detector that will detect the presence of smoke in the airstream of ductwork operating at no less than 300 fpm.  The DSDN detector offering detects the presence of smoke in the airstream without a minimum operating velocity.

For more complete details concerning detectors and their use please consult the engineering report or the specific data sheets of the detectors. Our engineering report goes into much greater detail on issues such as what are smoke detectors, why are they used, which type is recommended, how Ruskin factory mounts detectors, addressable vs. non-addressable detectors, and NFPA standards.

If further information is required please contact your local representative or Ruskin direct.