During a fire event, what is a key HVAC control action related to smoke control?

During a fire event, what is a key HVAC control action related to smoke control?

• A. Interlock dampers and fans, and either shut down or isolate HVAC as required while maintaining egress path pressurization.
• B. Increase general ventilation to dilute smoke.
• C. Run all HVAC at maximum.
• D. Ignore HVAC operation unless a fire alarm triggers.

Answer: (A)

Managing smoke movement and preserving safe egress paths is the priority in HVAC during a fire. The best action is to interlock dampers and fans with the fire event and either shut down or isolate the HVAC system as required, while keeping egress routes pressurized. This coordinated control stops smoke from circulating through ducts and spaces, which helps prevent smoke from reaching occupied areas and keeps stairwells and exits clearer for people evacuating. Keeping the HVAC from running at full blast or trying to dilute the smoke with general ventilation would just push smoke into more areas and across barriers, making evacuation harder. Ignoring HVAC operation until a fire alarm triggers misses automatic protective actions designed to limit smoke spread and protect occupants.

Managing smoke movement and preserving safe egress paths is the priority in HVAC during a fire. The best action is to interlock dampers and fans with the fire event and either shut down or isolate the HVAC system as required, while keeping egress routes pressurized. This coordinated control stops smoke from circulating through ducts and spaces, which helps prevent smoke from reaching occupied areas and keeps stairwells and exits clearer for people evacuating.

Keeping the HVAC from running at full blast or trying to dilute the smoke with general ventilation would just push smoke into more areas and across barriers, making evacuation harder. Ignoring HVAC operation until a fire alarm triggers misses automatic protective actions designed to limit smoke spread and protect occupants.