What device is used to help prevent smoke spread by shutting down the HVAC system during a fire?

The device that is instrumental in preventing smoke spread by shutting down the HVAC system during a fire is the duct smoke detector. These detectors are designed to sense the presence of smoke within the air duct systems of a building. When smoke is detected, the duct smoke detector sends a signal to shut down the HVAC system, which is crucial for limiting the movement of smoke throughout the building.

By initiating this shutdown, duct smoke detectors help to control smoke spread and provide a safer environment for occupants. This action also serves to prevent smoke from infiltrating other areas of the building, which can exacerbate the situation during a fire incident. The importance of duct smoke detectors lies in their role within fire protection strategies, ensuring that the HVAC system does not contribute to the dispersal of smoke and potentially harmful gases during emergencies.

In contrast, heat detectors generally respond to elevated temperatures but do not directly control smoking spread through HVAC systems, while fire alarms primarily function to alert occupants and facilitate evacuation, and ventilation systems themselves may otherwise contribute to smoke spread if not properly controlled.