Fire Dampers are fire production products that prevents the spread of fire inside the ductwork or plenum. When a rise in temperature occurs, the fire damper closes, usually activated by a thermal element which melts at temperatures higher than ambient or closes from an electrical signal from a fire alarm system utilizing detectors remote from the damper, indicating the sensing of heat or smoke in the building occupied spaces or in the HVAC duct system. Combination fire/smoke dampers are also available if a smoke barrier is desired at the same location as a fire barrier.