Question

During a fire alarm activation, which of the following will automatically shut down the entire HVAC system to minimize the air flow?

1) Smoke detectors
2) Heat detectors
3) Sprinkler system
4) Fire alarm control panel

Answer 1

During a fire alarm activation, smoke detectors will automatically shutdown the HVAC system to minimize airflow and prevent the spread of smoke. Smoke detectors use an ionization chamber to detect smoke, which then communicates with the fire alarm control panel to manage emergency protocols.

Step-by-step explanation:

During a fire alarm activation, it is typically the smoke detectors that are connected to an HVAC system which will automatically initiate the shutdown of the system. The purpose of this is to minimize the airflow that might feed the fire or spread smoke throughout the building. When a smoke detector senses smoke, it sends a signal to the fire alarm control panel, which then triggers various fire control measures, including the shutdown of the HVAC system.

The schematic of a smoke detector indicates an ionization chamber that can detect smoke through a disruption of ionized particles between charged metal plates, which is caused by smoke particles interfering with alpha particles emitted from an Americium source. This disruption is what activates the smoke alarm and can lead to a sequence of events for fire containment, including communications with the fire alarm control panel to manage building systems like the HVAC.