FSDs require local duct detector?

[welectrical]

It's standard to see fire smoke dampers provided with local duct detecting means, or detector located just outside of the duct within 5'-0" but is it actually a code requirement? The fire smoke rating is just to not that the damper is fire rated and smoke tight. If a space is fully sprinklered, then whenever a flow switch shows flow, the entire FA system starts and the dampers close anyways. So, what would be the point of the local detecting means?

 

[infinity]

It's standard to see fire smoke dampers provided with local duct detecting means

I've never seen such an arrangement. What would be the purpose of the local duct detector?

 

[ASG]

I's in the mechanical code.

607.3.3.2 Smoke damper actuation.

The smoke damper shall close upon actuation of a listed smoke detector or detectors installed in accordance with Section 606 of this code and Section 907.3 of the International Building Code and one of the following methods, as applicable:

1. Where a smoke damper is installed within a duct, a smoke detector shall be installed inside the duct or outside the duct with sampling tubes protruding into the duct. The detector or tubes within the duct shall be within 5 feet (1524 mm) of the damper. Air outlets and inlets shall not be located between the detector or tubes and the damper. The detector shall be listed for the air velocity, temperature and humidity anticipated at the point where it is installed. Other than in mechanical smoke control systems, dampers shall be closed upon fan shutdown where local smoke detectors require a minimum velocity to operate.

 

[infinity]

I's in the mechanical code.

607.3.3.2 Smoke damper actuation.

The smoke damper shall close upon actuation of a listed smoke detector or detectors installed in accordance with Section 606 of this code and Section 907.3 of the International Building Code and one of the following methods, as applicable:

1. Where a smoke damper is installed within a duct, a smoke detector shall be installed inside the duct or outside the duct with sampling tubes protruding into the duct. The detector or tubes within the duct shall be within 5 feet (1524 mm) of the damper. Air outlets and inlets shall not be located between the detector or tubes and the damper. The detector shall be listed for the air velocity, temperature and humidity anticipated at the point where it is installed. Other than in mechanical smoke control systems, dampers shall be closed upon fan shutdown where local smoke detectors require a minimum velocity to operate.

Your post only has one of the "following methods" what are the other ones?

 

[ASG]

2. Where a smoke damper is installed above smoke barrier doors in a smoke barrier, a spot-type detector shall be installed on either side of the smoke barrier door opening. The detector shall be listed for releasing service if used for direct interface with the damper.

3. Where a smoke damper is installed within an unducted opening in a wall, a spot-type detector shall be installed within 5 feet (1524 mm) horizontally of the damper. The detector shall be listed for releasing service if used for direct interface with the damper.

4. Where a smoke damper is installed in a corridor wall or ceiling, the damper shall be permitted to be controlled by a smoke detection system installed in the corridor.

5. Where a smoke detection system is installed in all areas served by the duct in which the damper will be located, the smoke dampers shall be permitted to be controlled by the smoke detection system.

This is copied from NYC since I can't seem to copy from IMC on the ICC site.

 

[gadfly56]

2. Where a smoke damper is installed above smoke barrier doors in a smoke barrier, a spot-type detector shall be installed on either side of the smoke barrier door opening. The detector shall be listed for releasing service if used for direct interface with the damper.

3. Where a smoke damper is installed within an unducted opening in a wall, a spot-type detector shall be installed within 5 feet (1524 mm) horizontally of the damper. The detector shall be listed for releasing service if used for direct interface with the damper.

4. Where a smoke damper is installed in a corridor wall or ceiling, the damper shall be permitted to be controlled by a smoke detection system installed in the corridor.

5. Where a smoke detection system is installed in all areas served by the duct in which the damper will be located, the smoke dampers shall be permitted to be controlled by the smoke detection system.

This is copied from NYC since I can't seem to copy from IMC on the ICC site.

I did a quick scan of the IMC from the ICC site and don't see any differences between NYC and the ICC version.

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