What is the primary function of a fire damper?

To close automatically upon detection of heat via a fusible link, stopping the spread of fire through ductwork penetrating a fire-rated barrier. (Clause 3.1)

What is the difference between a fire damper and a smoke damper?

A fire damper is heat-activated (fusible link) to stop fire. A smoke damper is typically motorized and connected to a smoke detection system to control the spread of smoke. (Clause 3.1 & 3.2)

What is a combination fire and smoke damper?

A damper that serves both functions: it closes via a fusible link in case of high heat and can also be controlled by a smoke detection system to manage smoke. (Clause 3.3)

What is the standard operating temperature for a fusible link?

The standard temperature is 74°C, which is low enough to react to a fire but high enough to avoid nuisance tripping from ambient heat. (Clause 6.2.1)

IS 13913

: 1993

Fire Dampers and Smoke Dampers for Air Distribution Systems - Specification

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This standard specifies the requirements for materials, construction, performance, and testing of fire dampers and smoke dampers used in HVAC air distribution systems. It aims to ensure these devices reliably prevent the spread of fire and smoke through ductwork penetrating fire-rated barriers. The code covers fire resistance ratings, leakage limits, and operational integrity.

Specifies requirements for the construction, performance, and testing of fire and smoke dampers used in air distribution systems.

Quick Reference Values

Fusible Link Operating Temperature74°C

Minimum Fire Resistance Rating90 minutes (1.5 hours)

Maximum Smoke Leakage Rate0.1 m³/s/m² at 250 Pa static pressure

Minimum Casing Sheet Thickness (GI)1.25 mm

Maximum Velocity Rating10 m/s

Maximum Operating Pressure1000 Pa

Practical Notes

Crucially, this 1993 standard has been superseded by IS 13913 (Part 1):2018 for fire dampers and IS 13913 (Part 2):2018 for motorized fire/smoke dampers. Always refer to the latest versions for new projects.

The fire rating of the damper must be selected to match the fire rating of the wall or slab it penetrates, as mandated by the National Building Code.

Correct installation is critical for performance. Ensure installation is done as per manufacturer's guidelines and the approved 'breakaway' connections for ducts are used to prevent structural damage during a fire.