While fire dampers help to limit the spread of fire, smoke dampers help to maintain the integrity of physical smoke barriers such as floors and walls. They can also be found in the ductwork of air conditioning and ventilation systems, and serve the same purpose as fire dampers in allowing building inhabitants to escape and allowing firefighters easy access. Smoke dampers, however, do not have the same temperature limits as fire dampers. They are frequently placed in regions where smoke penetration would provide particular problems. Smoke dampers serve two purposes in general:
- As part of a passive smoke system, where they are typically activated by smoke detectors located within the duct. They close when smoke is detected, preventing smoke and air from passing through the duct or ventilation opening.
- As part of a smoke control system that has been designed. This is intended to restrict smoke migration by utilising walls and floors as a barrier.
Smoke dampers are closed by an electrical, pneumatic, or spring actuator. They can be manually reset or pushed open by sending a reset signal to the actuator. Pneumatic actuators require air to work effectively, whereas electrical actuators require power to function well. Smoke dampers do not need to be put in sleeves and may instead be inserted straight into the duct. The connections between the damper frame and the duct, on the other hand, must be sealed to prevent air leakage.
Combination – Fire/Smoke Dampers
These are self-explanatory and, as the name suggests, serve as both a fire and a smoke damper. They are often utilised in HVAC penetrations when both smoke and fire dampers are required on a wall, ceiling, or floor. When smoke is detected, they either close through the smoke detector or close due to heat sensing via duct temperature. Unlike fire dampers, which require fusible connections, combination fire/smoke dampers feature electric heat release mechanisms. These are reversible and allow the damper to be regulated rather than slamming shut, producing pressure difficulties in the HVAC system.
Fire and smoke dampers are an important element of a building’s passive fire prevention system. As previously stated, smoke and fire dampers serve very similar functions and are installed in comparable locations. They are both intended to keep ducting from becoming a weak point in a building’s fire protection system, and are essentially louvred vents or shutters positioned within ducting that enable air to pass through normally but close in the case of a fire. Regular maintenance and inspection, like with any other building system, is required to guarantee proper operation.