14 Special Vent Ops

Question 1

Physical exertion of crews to reach the fire floor will mean

Answer 1

They may have less energy to perform firefighting functions

Question 2

Truck crews should never enter high rise empty handed. Of they aren’t carrying forced entry tools or vent equipment they should have

Answer 2

Space Scba cylinders
Hose
Tools
Lights

Question 3

Moving large amounts of tools is generally coordinated by those assigned to

Answer 3

Lobby control

Question 4

Low rise elevators

Answer 4

Floors 1-10

Question 5

Mid rise elevators

Answer 5

Only floors between low and high elevators ex, floor 1 and floor 10-20

Question 6

Highrise elevators

Answer 6

Serve only upper floors, ex.. Floor 1 and 20-30

Question 7

Express elevators

Answer 7

Ground floor to upper most floor. Ex. Floor 1 and 31 or whatever highest floor is

Question 8

Freight elevators

Answer 8

Serve some or all floors

Question 9

Freight elevators should be used whenever possible if approved by officer in charge because

Answer 9

They can handle the additional weight of ff’s in full ppe along with extra tools and equipment, weighting more than a ton

Question 10

Dangers of using elevators in a fire

Answer 10

Malfunction or damage from heat could recall elevator car to the fire floor or strand the elevator between floors in the shaft.

Question 11

Fire behavior in highrises is mostly affected by

Answer 11

Stack effect and mushrooming

Question 12

Stack effect

Answer 12

Natural vertical mvnt of air, or heat and smoke, in tall structures based on differences of air density inside and outside the buildings due to temp differences. Strong vertical column of mvnt.

Question 13

With the stack effect, the greater difference between the inside and outside temp and the greater the building height,

Answer 13

The greater the stack effect will be

Question 14

If temp is lower outside and hotter inside highrise the stack effect moves up. If it’s hotter outside and cooler inside it moves

Answer 14

Down and out, called reverse stack.

Question 15

Mushrooming, aka ceiling jets

Answer 15

Smoke rising until it hit barrier, then move horizontally until same. Then banks down and fills

Question 16

When smoke reaches the same temp as ambient air in the highrise, it loses its buoyancy and

Answer 16

Stratifies, forming layers of smoke in the building.

Question 17

Stratification can occur near the top floor and

Answer 17

Or several floors down below.

Question 18

Most ppv positioned at street level are only effective up to how many floors up

Answer 18

22

Question 19

If the building is higher than 22 floors, how do you vent with fans

Answer 19

Add more fans at the 22 floor or around there, or add smoke ejectors at the top most floor to be vented, or both

Question 20

Highrise vent options

Answer 20

Vertical or top ventilation
Horizontal fire floor
Horizontal above and below fire floor

Question 21

If vertical vent may endanger fleeing occupants, what might have to be used

Answer 21

Horizontal vent

Question 22

Fire and smoke should be vented vertically through stairwells and other vertical shafts, taking advantage of

Answer 22

The stack effect

Question 23

Vertical venting in highrises can prevent

Answer 23

Mushrooming on upper floors and does not promote lapping

Question 24

One of the biggest challenges to vertical or top venting is

Answer 24

Getting ff and equipment to the roof

Question 25

If the roof is within reach of an aerial on a highrise, it is the preferred method for

Answer 25

Moving manpower and equipment to the roof for venting

Question 26

If an aerial does not reach the roof, how can it be used to gain access

Answer 26

Reach the farthest floor it can, enter through a fire escape or window and use stair and elevators the rest of the way to the roof

Question 27

Although highrises usually have more than one stairway, few have more than one that

Answer 27

Terminates at the roof.

Question 28

During a fire, a stairwell can be relatively free of smoke but congested with

Answer 28

Occupants, attack lines and ff

Question 29

One stairwell must be dedicated to attack and the other to

Answer 29

Evacuation

Question 30

Elevators that service the fire floor or floors above should not be used unless

Answer 30

The officer in charge of the fire floor deems it safe to do so.

Question 31

If a bulkhead or penthouse is used to ventilate the stairwell that terminates at the roof, the door should be blocked open because

Answer 31

If it closes it could change the vent profile dangerously

Question 32

Ventilation in the stairwell that terminates at the top floor should be delayed until

Answer 32

All occupants have been evacuated or on an area of refuge

Question 33

Firefighters should be clear of the vent stairwell prior to venting because

Answer 33

Once it is opened, the stairwell can become untenable

Question 34

If buoyancy is the only force acting on gasses within a closed compartment, then in relation to atmospheric pressure, the pressure will be what at the top

Answer 34

Higher at the top and lower at the bottom

Question 35

Neutral pressure plane

Answer 35

Point in a highrise where interior pressure equals atmospheric pressure outside, moves up or down depending on wind and temp. May be in middle of building

Question 36

The neutral plane in a building without gasses being vented or openings made is where

Answer 36

Between 35-50% of the building height.

Question 37

In extreme distances between the neural plane, if openings are made at the top and bottom of a structure, the escape of high pressure at the top and inward pull of air at the bottom Causes

Answer 37

The entire building to act as a chimney, stack effect

Question 38

When air is pushed in a building by ppv it causes high pressure in the compartment and does what to the air

Answer 38

Forces it outside where there is lower pressure

Question 39

By dragging smoke out of a building with a smoke ejector, it causes negative pressure inside the compartment and

Answer 39

Forces the air out while dragging higher pressure air in from outside

Question 40

What can raise or lower the neutral pressure plane

Answer 40

Wind

Question 41

If the fire is above the neutral plane, if vented on the leeward side of the building it will

Answer 41

Vent naturally because the leeward side outside is lower pressure and the fire is in the higher pressure zone of the building

Question 42

Opening a window below the neutral pressure plane may

Answer 42

Draw air inside the building rather than allow smoke out of it, spreading fire

Question 43

The closer ventilation takes place near the neutral plane,

Answer 43

The less effect, positive or negative, wind will have on it

Question 44

Venting below the fire is not common but may be needed when smoke has spread to lower floors because of

Answer 44

Reverse stack effect

Question 45

Venting floors below the fire can be facilitated by

Answer 45

Using ppv blowers or other fans

Question 46

Venting on the fire floor first requires a knowledge of building layout because

Answer 46

Venting a dead end corridor or into a shaft that doesn't exit can cause vent problems or extension

Question 47

Horizontal venting on the fire floor should be done only when there is no other choice because

Answer 47

It can be Time consuming because of window construction, and dangerous to people on the street below

Question 48

To avoid hazards associated with horizontally venting sealed highrise buildings, what should be done

Answer 48

Vertical vent whenever possible.

Question 49

Vertical venting can be accomplished on intermediate highrise floors by

Answer 49

Venting smoke across the fire floor to the stairwell that reaches the roof. Maybe with assistance from fans.

Question 50

Venting above the fire will be most effective if the ok rices is started where

Answer 50

At the top of the building. Provides clear path out, and starting on the fire floor marry increase damage and put vent crew in danger

Question 51

Smoke dampers

Answer 51

Control airflow in hvac units, usually activated by fire alarm signaling system

Question 52

The actual manipulation of hvac system for smoke control should be left to

Answer 52

The building engineer, who much be available to IC for reference in venting under fd direction

Question 53

Guidelines for effectively using hvac system to control smoke mvnt

Answer 53

Operated only by building engineer Used to assist locating seat of fire Use to limit fire extension and smoke to smallest area possible Should not be allowed to spread fire or smoke beyond area of origin Provide fresh air to trapped occupants in refuge areas

Question 54

To accomplish manual shut down of smoke dampers with the least delay, building engineer should be contacted when

Answer 54

As soon as the fd arrives

Question 55

Curtain boards

Answer 55

Vertical boards, fire resistive half walls that extend down from roof to limit spread of fire and smoke

Question 56

Nfpa 204

Answer 56

Standard for smoke and heat venting

Question 57

Automatic roof vents are intended to limit the spread of fire within a building by

Answer 57

Releasing heat and smoke into the outside before it mushrooms

Question 58

Because automatic roof vents work on their own, it may reduce or eliminate the need for

Answer 58

Additional vertical venting

Question 59

Automatic roof vents may be activated by smoke detectors but otherwise, most still operate using

Answer 59

Spring loaded or counterweight cover assembly with fusible link activator

Question 60

Prevailing winds may prevent automatic roof vents from working, this may require

Answer 60

The vents to be closed and horizontal used instead

Question 61

Sprinklers operating near roof vents may not allow heat to activate them, firefighters should not try to force open vents because it can damage them, but rather they should

Answer 61

Be familiar with manual controls

Question 62

Highrise fires present numerous challenges, including

Answer 62

``` Limited access Large number of offices or apartments Heavy occupant loads Falling glass or debris Rapid smoke and fire spread through shafts Locked interior doors Low water pressure Climbing a lot of stairs ```

Question 63

Monitors are primarily intended to increase natural light in a building but may also provide

Answer 63

Natural ventilation

Question 64

Most monitors have wires glass or glass panels sloping down from their ridge as a roof and rely on what for ventilation

Answer 64

Rely on the glass breaking for vent

Question 65

Monitors with solid walls may have panels hinged at the bottoms with fusible links to

Answer 65

Open automatically from gravity when fire needs to vent

Question 66

Curtain are intended to confine the fire to an area over its source, the walls generally extend how far

Answer 66

A distance of at least 20 percent the vertical distance from the floor to roof but no lower than 10 feet

Question 67

Curtain board may help accelerate the activation of

Answer 67

Sprinkler heads over the area of origin

Question 68

Usually but not always, cellars will have no windows and basements will have

Answer 68

Small windows between grade level and first floor

Question 69

Early ventilation of fire below grade is critically important to firefighting operations because

Answer 69

Pipe chases, shafts, chutes etc can contribute to fire spread on upper floors

Question 70

If an opening in a basement can be made opposite the interior entry point, the fastest way of venting may be

Answer 70

Ppv in the interior point of entry as crews enter with a line.

Question 71

If no openings can be made in a cellar how do you vent

Answer 71

Cut a hole on the first floor near a window and position a smoke ejector to facilitate vent

Question 72

Windowless building require what type of vent

Answer 72

Fast vertical vent to prevent backdraft