Ch 9 pg 240-247
43 Questions
10 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What was the initial purpose of testing positive pressure ventilation (PPV)?

  • To improve air quality in smoke-filled environments
  • To enhance the efficiency of firefighting
  • To reduce stack effect in high-rise fires (correct)
  • To increase the rate of fire containment

Which fire department expanded the use of positive pressure ventilation beyond high-rises?

  • Los Angeles Fire Department (correct)
  • New York Fire Department
  • Chicago Fire Department
  • Miami Fire Department

What negative outcome can result from improper use of positive pressure ventilation?

  • Longer firefighting times
  • Decreased visibility
  • Increased stack effect
  • Fanning smolders into a conflagration (correct)

How does positive pressure in a stairwell affect heated gas flows?

<p>It reverses their flow away from attack crews (A)</p> Signup and view all the answers

What is an important factor for the effectiveness of positive pressure ventilation on the fireground?

<p>Understanding what environmental conditions exist (B)</p> Signup and view all the answers

What is a potential disadvantage of using hose streams on minor fires?

<p>They can use up water needed for fire control. (A)</p> Signup and view all the answers

Which factor is NOT mentioned as a drawback of using smoke ejectors and similar devices?

<p>Need for continuous maintenance (D)</p> Signup and view all the answers

In which situation should hose streams be avoided due to potential safety hazards?

<p>In areas of below freezing temperatures (B)</p> Signup and view all the answers

What positional distance from the window is recommended to create a venturi effect?

<p>6-8 feet (B)</p> Signup and view all the answers

What is a possible risk when attempting to ventilate from the window in a commercial area?

<p>Igniting smoldering materials. (B)</p> Signup and view all the answers

What angle of the nozzle pattern is identified as optimum for air flow?

<p>30 (D)</p> Signup and view all the answers

What is one significant drawback of early mechanical ventilation methods for firefighter smoke removal?

<p>Fans often did not fit openings correctly. (D)</p> Signup and view all the answers

Which of the following modes of operation is NOT typically associated with smoke-removal devices?

<p>Creating a vacuum to trap smoke. (D)</p> Signup and view all the answers

What issue arises when fans are improperly fitted in mechanical ventilation systems?

<p>They lead to a churning effect that decreases efficiency. (D)</p> Signup and view all the answers

What was the common use of mechanical ventilation techniques in the first two decades?

<p>Primarily as exhaust devices for smoke removal. (A)</p> Signup and view all the answers

What is one advantage of positive pressure ventilation compared to negative pressure methods?

<p>It effectively expels smoke while introducing fresh air. (D)</p> Signup and view all the answers

Which consideration is least critical when planning the use of PPV in a fire situation?

<p>The status of the building's overall structural integrity (B)</p> Signup and view all the answers

What key factor should NOT be overlooked when using PPV?

<p>The timing for opening and closing windows (D)</p> Signup and view all the answers

Which factor should be assessed to determine the effectiveness of PPV?

<p>The location and extent of the fire (A)</p> Signup and view all the answers

What condition would make the implementation of PPV hazardous for victims and firefighters?

<p>Entering through points other than where the PPV fan is operating (D)</p> Signup and view all the answers

What is the primary purpose of making an opening at the top of multistory structures?

<p>To facilitate the upward movement of fire gases. (D)</p> Signup and view all the answers

Which architectural feature is most commonly associated with vertical fire spread?

<p>Staircases (C)</p> Signup and view all the answers

What is a common feature of staircases in multistory buildings concerning fire safety?

<p>They can extend past the top floor onto the roof. (A)</p> Signup and view all the answers

What is the primary purpose of leaning the door against the bulkhead at a 45° angle?

<p>To establish a ramp for reaching heights (A)</p> Signup and view all the answers

Which tool is used to secure the door in place while using it as a ramp?

<p>A Halligan tool (C)</p> Signup and view all the answers

How should the forked end of the Halligan tool be positioned when securing the door?

<p>Parallel to the bottom edge of the door (B)</p> Signup and view all the answers

What is required for the firefighter to successfully ascend the ramp created by the door?

<p>A running start (A)</p> Signup and view all the answers

What height range can the bulkhead reach above the roof level?

<p>8 to 10 feet (B)</p> Signup and view all the answers

Which of the following statements about breaking skylights is true in the context of firefighter operations?

<p>Personnel ascending the stairs need to be considered before proceeding. (C)</p> Signup and view all the answers

What common issue arises in most fire departments regarding the response of ladder trucks?

<p>There is usually a delay in the ladder truck's arrival compared to the engine. (C)</p> Signup and view all the answers

What is an important precaution to take when providing ventilation over a critical vertical artery during a fire?

<p>Check if the stairway is clear of personnel before acting. (C)</p> Signup and view all the answers

What was the main purpose of dumbwaiter shafts in late 1800s through early 1900s buildings?

<p>To simplify garbage disposal (D)</p> Signup and view all the answers

How does fire typically extend in a building with trash shoots?

<p>By finding alternative vertical pathways (B)</p> Signup and view all the answers

What is a significant benefit of removing the lid of a dumbwaiter shaft during a fire emergency?

<p>It delays horizontal fire extension into the cockloft (D)</p> Signup and view all the answers

What role does the soil pipe serve in fire scenarios?

<p>It indicates potential vertical fire extension pathways (A)</p> Signup and view all the answers

When checking for fire extension, what should be done with the soil pipes on each floor?

<p>Feel for heat and check the base (B)</p> Signup and view all the answers

The danger with vertical ventilation of staircases much as with horizontal ventilation is what?

<p>Geometry and wind direction (A)</p> Signup and view all the answers

For the first ___ or so years mechanical ventilation used exhaust devices most commonly

<p>20</p> Signup and view all the answers

The idea of fans blowing in fresh air was originally tested as a way of reducing _____ effect

<p>Stack</p> Signup and view all the answers

PPV the fan is set up __ to 12 ft away from the desired opening

<p>8</p> Signup and view all the answers

The danger with venting over a staircase is much the same as with horizontal vent, depends on the building ____ and wind direction

<p>Geometry</p> Signup and view all the answers

Dumbwaiter shafts were replaced with compactors and ____

<p>Incinerators</p> Signup and view all the answers

Pg 246 says that the second most common vertical avenue is the ____

<p>Pipe chase</p> Signup and view all the answers

Flashcards

Hose Stream Ventilation

Using a hose stream to create airflow and remove smoke, reducing the intensity of a fire.

Venturi Effect Ventilation

A method for improving the effectiveness of a hose stream by positioning the nozzle 6-8 feet from the target, creating a Venturi effect that increases the air flow.

Narrow Hose Stream

Reducing the size of a hose stream to achieve a narrower and potentially safer spray of water, useful in situations where maintaining a safe distance is essential.

Hose Stream Depletion

The potential dangers associated with using a hose stream on small fires, as it can deplete valuable water resources needed for larger fires.

Signup and view all the flashcards

Hose Stream in Freezing Temperatures

The risk of using a hose stream in freezing temperatures, as ice can form, creating hazardous trip and slip conditions.

Signup and view all the flashcards

Smoke Removal Devices

Mechanical devices like smoke ejectors, blowers, and exhaust fans used to remove smoke and create safer fire fighting conditions by bypassing some limitations of hose streams.

Signup and view all the flashcards

Smoke Removal Device Hazards

The risk of using smoke removal devices near explosive gases, requiring careful assessment of the environment and the presence of potentially volatile substances.

Signup and view all the flashcards

Positive Pressure Ventilation (PPV)

A ventilation technique involving directing fresh air into a burning structure, pushing out smoke and heat, potentially assisting in fire control.

Signup and view all the flashcards

PPV Safety Concerns

The potential for PPV to unintentionally direct flames towards victims or firefighters, necessitating careful planning and strategic deployment.

Signup and view all the flashcards

Mechanical Ventilation

The use of mechanical devices to create airflow, either extracting smoke or introducing fresh air, effectively managing fire conditions.

Signup and view all the flashcards

Exhaust Techniques

Historical focus on extracting smoke, often resulting in limited effectiveness due to inadequate sealing around devices, highlighting the importance of proper sealing for effective ventilation.

Signup and view all the flashcards

PPV Target Safety

The importance of ensuring that PPV strategies do not accidentally direct flames towards victims, requiring careful planning and situational awareness.

Signup and view all the flashcards

PPV Resource Check

The necessity of checking hoselines and water supply status before deploying PPV, ensuring sufficient resources for effective fire suppression.

Signup and view all the flashcards

PPV Deployment Criteria

The need to avoid using PPV on contained and well-ventilated fires, as it may create unnecessary risks and complications.

Signup and view all the flashcards

Window Control in PPV

Strategic opening and closing of windows during PPV operations to optimize airflow and enhance the effectiveness of smoke removal.

Signup and view all the flashcards

Vertical Ventilation Strategies

Creating openings above vertical shafts like stairwells to allow for efficient heat and smoke evacuation, improving safety and accessibility.

Signup and view all the flashcards

Ventilation via Skylights

The importance of skylights in ventilation, providing a crucial outlet for heat and smoke, but requiring caution during glass breaking operations.

Signup and view all the flashcards

Opening Bulkheads

The crucial step of promptly opening bulkheads once hoselines operate, enabling effective heat and smoke management during fire suppression.

Signup and view all the flashcards

Door-Ramp Technique

Using a securely positioned ramp created by leaning a door, facilitating access to high bulkheads for firefighters, improving operational efficiency.

Signup and view all the flashcards

Trash Chute Fire Hazards

The presence of trash chutes, now often replaced by compactors, which can act as vertical fire conduits, potentially allowing fires to spread rapidly to upper levels.

Signup and view all the flashcards

Dumbwaiter Shaft Hazard

The potential for fire to extend into dumbwaiter shafts, particularly if they contain skylights, requiring prompt access to prevent horizontal fire spread.

Signup and view all the flashcards

Soil Pipe Identification

Using soil pipes as indicators of vertical pipe arteries, helping identify potential fire extension points within a structure.

Signup and view all the flashcards

Heat Check on Soil Pipes

Checking for heat along soil pipes to assess potential fire movement into the attic, providing valuable information regarding fire spread direction.

Signup and view all the flashcards

Ventilation

Applying ventilation techniques to remove smoke and heat from a structure, creating a safer environment for firefighting operations and occupants.

Signup and view all the flashcards

Ventilation Considerations

Understanding the limitations and risks associated with various ventilation techniques, ensuring safe and effective fire suppression strategies.

Signup and view all the flashcards

Ventilation Tactics

A strategic approach to ventilation involving the use of hose streams, PPV, or other techniques to control the spread of smoke, heat, and flames.

Signup and view all the flashcards

Ventilation as a Firefighting Tool

The use of ventilation techniques combined with other firefighting tactics to effectively control a fire and save lives.

Signup and view all the flashcards

Study Notes

Geometry of Ventilation

  • Venturi effect improves stream efficiency by positioning 6-8 feet from window or door.
  • In commercial settings, this distance may expose firefighters to smoldering materials, risking reignition.
  • A narrower stream can be used if maintaining distance is necessary for safety.

Hose Stream Limitations

  • Using a hose stream on small fires can deplete limited water supplies needed for control.
  • Avoid using hose streams in freezing temperatures; ice can create fall hazards.

Smoke Removal Devices

  • Smoke ejectors, blowers, and exhaust fans are effective without the limitations of hose streams.
  • Care must be taken regarding power supply availability and safety around explosive gases.

Positive Pressure Ventilation (PPV)

  • PPV can reverse heat and gas flow, aiding in fire attack via strategic airflow.
  • Originally used to combat stack effect in high-rise fires, has been adapted for various structures.
  • Must be used with care to prevent directing flames onto victims or firefighters.

Mechanical Ventilation

  • Mechanical ventilation can channel combustion products effectively by either sucking smoke out or blowing fresh air in.
  • Historically focused on exhaust techniques which were less effective due to poor sealing around devices.

Key Considerations for PPV Use

  • Ensure the strategy does not blow fire towards victims.
  • Assess all hoselines and water supply status before deployment.
  • Avoid using PPV if the fire is contained and well-ventilated.
  • Coordinate the opening and closing of windows during the operation to optimize airflow.

Vertical Ventilation Strategies

  • Create openings above vertical arteries like staircases for effective heat and smoke evacuation.
  • Skylights provide a crucial opportunity for ventilation, and caution is advised when breaking glass for this purpose.

Bulkhead and Ladder Techniques

  • Opening bulkheads promptly is essential once hoselines operate to manage heat and smoke.
  • Use of a secured ramp created by leaning a door can assist firefighters in reaching high bulkheads.

Structural Considerations

  • Early 20th-century buildings employed trash chutes, now often replaced by compactors.
  • Fires extending into trash chutes can rapidly progress to upper levels.
  • Dumbwaiter shafts may feature skylights that can prevent horizontal fire extension if accessed promptly.

Soil Pipe Identification

  • Soil pipes indicate the presence of vertical pipe arteries and can help locate fire extension points.
  • Checking for heat along soil pipes can provide insight into potential fire movement towards the attic.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Description

This quiz explores the principles of geometry concerning the openings in windows and doors, particularly in commercial settings. Learn how the positioning relative to these openings can affect airflow and efficiency, specifically focusing on the venturi effect in real-world applications.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser