NICET Level 2 Fire Alarm Systems 2025 – 400 Free Practice Questions to Pass the Exam

Smoke detectors installed in HVAC ducts are critical components in fire detection and prevention systems, serving to identify smoke present in the airflow of the duct system. According to NFPA standards, these detectors play a vital role in ensuring the safety of occupants and the integrity of the building by allowing for a prompt response to potential fire conditions.

The reason why the correct answer includes both "Alarm" and "Supervisory" is rooted in the functions these detectors must perform. When smoke is detected in the ductwork, the system needs to trigger an alarm to alert occupants and facilitate an immediate evacuation or response. This is the alarm function, which ensures that the fire condition is acknowledged.

In addition to the alarm function, smoke detectors in ducts also serve a supervisory role. This means they monitor the status of the ductwork and provide feedback on the operational state of the detection system. If there is a malfunction, such as a blockage or the detector failing to operate, supervisory signals will alert the control panel. This is crucial for maintaining the integrity and reliability of the fire alarm system.

Thus, the requirement for smoke detectors in HVAC ducts to initiate either an alarm or supervisory signal aligns with ensuring that both immediate dangers are addressed and that the overall system remains functional and effective for fire