Podcast Beta
Questions and Answers
What is the main priority at any high-rise incident?
How many factors contribute to smoke movement in a high-rise building?
What is the primary effect of expansion due to heat from a fire?
What is the term used to describe the movement of air inside a tightly sealed building?
Signup and view all the answers
How does buoyancy affect smoke movement?
Signup and view all the answers
What is the purpose of referencing TN 101.1.2 - HVAC?
Signup and view all the answers
What is the term used to describe smoke that has migrated to the uppermost part of a building and been forced back down by hotter, rising smoke and gases?
Signup and view all the answers
What is the primary responsibility of the Ventilation Sector Officer?
Signup and view all the answers
What should be done to the air handling system if it is spreading smoke within the building?
Signup and view all the answers
What is the purpose of activating supply fans in certain HVAC zones?
Signup and view all the answers
What should be implemented if building supply fans are not activated or unavailable?
Signup and view all the answers
What is the responsibility of the Ventilation Sector Officer when it comes to stairwell doors?
Signup and view all the answers
Study Notes
Ventilation in High-Rise Buildings
- Ventilation is a priority at any high-rise incident.
Mechanisms of Smoke Movement
- Five factors cause smoke to move throughout a high-rise building: Expansion, Buoyancy, HVAC Systems, Stack Effect, and Mushrooming Effect.
- Expansion and Buoyancy fill areas closer to the fire's origin with smoke.
- HVAC Systems and Stack Effect can rapidly fill the entire building with smoke.
- These four mechanisms can act in conjunction with one another to fill an entire building with smoke.
Expansion
- Heat from a fire causes gas to expand, typically three to four times in volume.
- In compartments with limited openings, this can cause an increase in pressure, driving smoke into adjacent compartments.
Buoyancy
- Superheated gases are less dense than the surrounding air and therefore more buoyant.
- This buoyant smoke/air migrates into adjacent compartments, particularly those above the fire compartment.
HVAC Systems
- A building's HVAC system can either enhance or interfere with the ventilation of smoke and gases.
Stack Effect
- The movement of air inside a tightly sealed building due to the temperature difference between the inside and outside of a building.
Mushrooming Effect
- Smoke that has migrated to the uppermost part of a building and been forced back down, in a boiling or rolling motion, by hotter, rising smoke and gases.
Tactical Considerations for the Ventilation Sector Officer
- The Ventilation Sector Officer may be Mobile or Static based on the size and complexity of the incident.
Investigation
- The Ventilation Sector Officer directs at least two Firefighters to each stairwell to determine smoke conditions.
- They travel each stairwell in its entirety, checking to ensure stairwell doors on each floor are closed and smoke conditions on each floor.
- They receive updates from personnel regarding smoke conditions at different floor levels.
- They notify the Incident Commander of smoke conditions and update them on changes.
Stairwell Strategy
- The Ventilation Sector Officer identifies the fire attack stairwell and evacuation stairwell.
- Attempts are made to restrict entry or remove occupants from fire attack stairwells.
- Ventilation strategies are developed in conjunction with stairwell search and secure initiatives.
Determine Fire Floor
- The Ventilation Sector Officer monitors communications from the primary team(s) regarding the location and extent of the fire and smoke conditions.
Determine Status of HVAC System
- If the air handling system is spreading smoke within the building, it should be manually shut down.
- The air handling system should remain operational if it is pressurizing uncontaminated areas or exhausting smoke from the fire area.
Positive Pressure Ventilation
- If building supply fans are not activated or unavailable, then Positive-Pressure Ventilation (PPV) must be implemented by firefighters.
- Use PPV as per TN 105.5 – Positive Pressure Ventilation if trying to pressurize stairwells and keep smoke contained.
Entry Control
- If the Ventilation Sector Officer is Mobile, all PITs are transferred to Entry Control.
- If the Ventilation Sector Officer remains Static outside the Controlled Area, crews shall PIT in with Ventilation Sector Officer or a dedicated Entry Control.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Learn about the basic principles of ventilation in high-rise buildings and the five factors that cause smoke to move during an incident.
