Smoke Control and HVAC Systems Flashcards

What is the purpose of stairwell pressurization?

Answer: To keep smoke out of the exit stair by maintaining higher pressure inside

Positive pressure in the stair prevents smoke from entering the protected exit path.

Under NFPA 92, what is the typical maximum force allowed to open an exit door in a pressurized smoke control system?

Answer: 30 lbf

Door opening force must not exceed 30 lbf so occupants can still exit.

What is the minimum design pressure difference across a smoke barrier in a sprinklered building per NFPA 92?

Answer: 0.05 in. w.c.

NFPA 92 lists 0.05 in. water column as the minimum for sprinklered spaces with typical ceiling heights.

What is the Firefighter's Smoke Control Station (FSCS)?

Answer: A control panel giving firefighters manual override of smoke control equipment

The FSCS lets the fire department monitor and manually control fans and dampers.

When the FSCS issues a manual command that conflicts with an automatic smoke control sequence, which takes priority?

Answer: The FSCS manual command

Manual commands at the FSCS have the highest priority over automatic and BMS controls.

What does 'zoned smoke control' generally do in the fire zone?

Answer: Exhausts the fire zone while pressurizing adjacent zones

Exhausting the fire zone and pressurizing neighbors keeps smoke contained to its zone of origin.

Why are dedicated smoke control systems tested periodically more often than non-dedicated ones?

Answer: They are never used for normal HVAC, so faults would otherwise go unnoticed

Dedicated systems sit idle in normal operation, so testing is the only way to confirm they still work.