F80 Smoke Control and HVAC Systems

Question 1

During a high-rise fire, what is the primary purpose of stairwell pressurization?

Accepted Answer

To prevent smoke from infiltrating evacuation stairwells

Answer

Stairwell pressurization creates a positive air pressure differential that prevents smoke from migrating into the stairwell, keeping evacuation routes tenable for building occupants and firefighters.

Question 2

When a fire is confirmed in a high-rise building, what is the correct action regarding the HVAC system serving the fire floor?

Accepted Answer

Shut down HVAC serving the fire floor to prevent smoke spread through ductwork

Answer

HVAC systems can rapidly distribute smoke throughout a building via ductwork. Shutting down HVAC on the fire floor — and often the floors immediately above and below — is standard procedure to contain smoke spread.

Question 3

A smoke damper's primary function in a fire is to:

Accepted Answer

Close automatically to prevent smoke migration through duct openings in fire barriers

Answer

Smoke dampers are installed in HVAC ducts where they penetrate smoke barriers. On activation (typically via smoke detector or fire alarm), they close to maintain the integrity of smoke compartments.

Question 4

In a high-rise building, which area is typically maintained at the HIGHEST air pressure during a smoke control event?

Accepted Answer

The protected stairwell enclosure

Answer

Protected stairwells are pressurized to the highest level so that when doors are opened, air flows outward into corridors rather than allowing smoke to enter. This maintains tenable conditions in the primary evacuation route.

Question 5

The Fire Safety Director receives an alarm indicating smoke detector activation in the return air plenum. What is the MOST likely concern?

Accepted Answer

Smoke is being drawn from a fire location and distributed through the HVAC return system

Answer

Return air plenums collect air from occupied spaces before recirculating it. A smoke alarm in the return plenum is a strong indicator that smoke from a fire is entering the HVAC system and risks being distributed building-wide.

F80 Practice Test

F80 Practice Test

F80 Smoke Control and HVAC Systems