It is important to shut down the HVAC system because the movement of air will both feed the fire and spread smoke throughout the building.

It is important to shut down the HVAC system because the movement of air will both feed the fire and spread smoke throughout the building.

• A. True
• B. False
• C. Only during maintenance
• D. It has no effect on fire safety

Answer: (A)

Airflow from HVAC systems can feed a fire by supplying it with oxygen and can push smoke through ducts and into other parts of the building. Shutting down or isolating the HVAC reduces those air pathways, cutting off the extra oxygen to the fire and limiting the spread of smoke. This helps contain the fire and makes evacuation safer because smoke is less likely to travel to adjacent areas. It’s a fire safety measure that applies during an incident, not just during maintenance, and saying it has no effect would ignore how ventilation interacts with fire and smoke movement.

Airflow from HVAC systems can feed a fire by supplying it with oxygen and can push smoke through ducts and into other parts of the building. Shutting down or isolating the HVAC reduces those air pathways, cutting off the extra oxygen to the fire and limiting the spread of smoke. This helps contain the fire and makes evacuation safer because smoke is less likely to travel to adjacent areas. It’s a fire safety measure that applies during an incident, not just during maintenance, and saying it has no effect would ignore how ventilation interacts with fire and smoke movement.