Ch 18 pg 461-464 Ventilation at High-Rise Fires

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Questions and Answers

What essential equipment should the two firefighters who go to the top floor have when responding to a fire in a high rise?

Fire hose and ladder

SCBA and forcible entry tools (correct)

Water pump and emergency radio

Thermal imaging camera and fire blanket

What is a critical factor for the Incident Commander (IC) to consider before allowing the HVAC system to operate?

The type of building materials used

The time of day the fire started

The color of the smoke

The exact location of the fire (correct)

What two factors outweigh all other others for ventilation in high-rise fires?

Temperature and humidity

Building design and fire load

Occupant density and response time

Wind and the stack effect (correct)

When is it most appropriate to utilize the HVAC system for ventilation during a fire?

In cases of small fires that do not require window breaking Signup and view all the answers

What is the primary reason that vertical ventilation often becomes difficult to achieve in high-rise buildings?

The complexity of the stack effect. Signup and view all the answers

What defines the stack effect?

Natural movement of air through the building. Warm air rises Signup and view all the answers

What should a firefighting team do first upon reaching the roof of a high-rise building during a fire?

Contact the Incident Commander and check the fires reaction to their briefly opening of the door while the door to the fire area is also open. Signup and view all the answers

What additional steps should be taken after accomplishing initial ventilation on the roof?

Make additional openings at the elevator bulkheads and penthouses Signup and view all the answers

What should firefighters prioritize when using stairs during a fire evacuation?

Ensuring the ventilation stairway door remains shut during ascent Signup and view all the answers

What challenges might occur when attempting to land a helicopter on a high-rise rooftop during a fire?

Thermal updrafts hindering pilot visibility and control Signup and view all the answers

What is a necessary condition for a helicopter to land safely on a rooftop?

A flat roof structure devoid of obstructions Signup and view all the answers

When evacuating occupants from a building during a fire, what should firefighters do with those in the stairway?

Direct them to designated stairs for safer evacuation Signup and view all the answers

What is a primary danger of using elevator shafts for ventilation during a fire in tall buildings?

Firefighters may fall into the elevator shaft due to lack of visibility. Signup and view all the answers

Why is it not effective to vent a floor using the elevator hoistway?

There are only small openings available at the top of the hoistway for venting. Signup and view all the answers

What action should be taken regarding the elevator hoistway door on the fire floor during ventilation efforts?

It should remain closed to prevent smoke and heat from spreading. Signup and view all the answers

What should be done to vent smoke that has entered the elevator shaft?

Open the elevator room door at the roof. Signup and view all the answers

What happens during the stratification of smoke in sealed buildings?

Smoke settles at lower levels due to insufficient heat. Signup and view all the answers

What is the reverse stack effect in high-rises?

A downward movement of smoke due to the cooling of fire gases. Signup and view all the answers

In which situation is smoke stratification most likely to occur?

In sealed buildings with low smoke temperatures. Signup and view all the answers

What phenomenon occurs in air-conditioned high-rise buildings during hot weather?

Reverse stack effect Signup and view all the answers

Under what conditions is the reverse stack effect likely to pose a severe problem?

On very hot days with fire on upper floors Signup and view all the answers

Study Notes

Ventilation Strategies in High-Rise Fires

Ventilation is crucial for removing smoke and heat during serious fires, with options including vertical ventilation via stairways, horizontal ventilation through windows, and HVAC systems.
Both natural and mechanical methods can be employed to move fire gases; wind and the stack effect are key factors influencing upper-level ventilation decisions.

Vertical Ventilation Considerations

Important information for using HVAC systems includes fire location, floor layout, stair placement, HVAC openings, personnel locations, and current fire conditions.
Knowledge of these elements is essential before controlling smoke with HVAC systems to avoid endangering firefighters or civilians.

Understanding the Stack Effect

The stack effect is the upward movement of warm air in tall buildings, becoming significant in structures above 60 feet.
This natural air movement is present year-round and can accelerate with height, allowing smoke and gases to escape if upper windows are opened, especially beneficial during fires.

Firefighting Procedures

Firefighters should carry SCBA and forcible entry tools, using elevators only to two floors below the fire before taking stairs to the roof.
Maintain the fire floor door closed until reaching the roof to prevent exposure to smoke and flames; clear stairways of occupants, redirecting them to evacuation routes.

Helicopter Deployment in Firefighting

Helicopters can be used for rooftop ventilation but require prior planning and practice; difficult conditions can complicate this during emergencies.
Upon arrival at the roof, firefighters must assess fire behavior when opening doors to ensure safety and effectiveness in ventilation.

Utilizing Elevators in Ventilation

Using elevator shafts for ventilation is discouraged due to the dangers posed by open hoistway doors and insufficient venting capacity.
Recommended practice involves venting through the roof while keeping hoistway doors on fire floors closed to prevent smoke and heat spread.

Unique Phenomena in High-Rise Fires

Smoke stratification can occur when smoke does not rise sufficiently due to inadequate heat, causing it to accumulate below upper floors.
Inverse stack effect represents a situation where cooler indoor air draws smoke downward during hot weather, which can complicate fire management but is generally manageable unless significant temperature differences exist.

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Description

This quiz covers essential strategies for ventilation during high-rise fires. It explores various methods including vertical and horizontal ventilation, as well as the use of HVAC systems. Understanding these techniques is crucial for effective smoke and heat removal in emergency situations.