In general a fire damper works when heat from a fire causes the normal temperature of a room to rise to approximately 165 degrees Fahrenheit i.e. it is designed to close automatically on the detection of heat. The fusible link which is attached to the damper melts causing the dampers' door to close.

What is a fire damper and how does it work?

In general a fire damper works when heat from a fire causes the normal temperature of a room to rise to approximately 165 degrees Fahrenheit i.e. it is designed to close automatically on the detection of heat. The fusible link which is attached to the damper melts causing the dampers' door to close.

How does fire smoke damper work?

Fire dampers respond to heat, when the temperature reaches a set point the damper slams shut. Smoke dampers respond to the detection of smoke, and close automatically. ... They resist the passage of smoke, toxic gases and air through a fire barrier.