Essentials Of Ff Chap 11

Front 1

Bowstring Truss

Back 1

Lightweight truss design noted by the bow shape, or curve, of the top chord.

Front 2

Chimney Effect

Back 2

Created when a ventilation opening is made in the upper portion of a building and air currents throughout the building are drawn in the direction of the opening; also occurs in wildland fires when the fire advances up a V-shaped drainage swale.

Front 3

Churning

Back 3

Movement of smoke being blown out of a ventilation opening only to be drawn back inside by the negative pressure created by the ejector because the open area around the ejector has not been sealed. Also called recirculation.

Front 4

Forced Ventilation

Back 4

Any means other than natural ventilation. This type of ventilation may involve the use of fans, blowers, smoke ejectors, and fire streams. Also called Mechanical Ventilation.

Front 5

Horizontal Ventilation

Back 5

Any technique by which heat, smoke, and other products of combustion are channeled horizontally out of a structure by way of existing or created horizontal openings such as windows, doors, or other holes in walls.

Front 6

Hydraulic Ventilation

Back 6

Method of ventilating a fire building by directing a fog stream of water out a window to increase air and smoke movement.

Front 7

Kerf Cut

Back 7

A single cut the width of the saw blade made in a roof to check for fire extension.

Front 8

Louver Cut or Vent

Back 8

Rectangular exit opening cut in a roof, allowing a section of roof deck (still nailed to a center rafter) to be tilted, thus creating an opening similar to a louver. Also called center rafter cut.

Front 9

Lamella Arch

Back 9

A special type of arch constructed of short pieces of wood called lamellas.

Front 10

Leeward Side

Back 10

Protected side; the direction opposite from which the wind is blowing.

Front 11

Mushrooming

Back 11

Tendency of heat, smoke, and other products of combustion to rise until they encounter a horizontal obstruction. At this point they will spread laterally until they encounter vertical obstructions and begin to bank downward.

Front 12

Natural Ventilation

Back 12

Techniques that use the wind, convection currents, and other natural phenomena to ventilate a structure without the use of fans, blowers, or other mechanical devices.

Front 13

Negative-Pressure Ventilation

Back 13

Technique using smoke ejectors to develop artificial circulation and to pull smoke out of a structure. Smoke ejectors are placed in windows, doors, or roof vent holes to pull the smoke, heat, and gases from inside the building and eject them to the exterior.

Front 14

Positive-Pressure Ventilation (PPV)

Back 14

Method of ventilating a confined space by mechanically blowing fresh air into the space in sufficient volume to create a slight positive pressure within and thereby forcing the contaminated atmosphere out the exit opening.

Front 15

Purlin

Back 15

Horizontal member between trusses that supports the roof.

Front 16

Pyrolysis (Pyrolysis Process or Sublimation)

Back 16

Thermal or chemical decomposition of fuel (matter) because of heat that generally results in the lowered ignition temperature of the material. The pre-ignition combustion phase of burning during which heat energy is absorbed by the fuel, which in turn gives off flammable tars, pitches, and gases.

Front 17

Roof Covering

Back 17

Final outside cover that is placed on top of a roof deck assembly. Common roof coverings include composition or wood shake shingles, tile, slate, tin, or asphaltic tar paper.

Front 18

Roof Ladder

Back 18

Straight ladder with folding hooks at the top end. The hooks anchor the ladder over the roof ridge.

Front 19

Stack Effect

Back 19

Phenomenon of a strong air draft moving from ground level to the roof level of a building. Affected by building height, configuration, and temperature differences between inside and outside air.

Front 20

Thermal Column

Back 20

Updraft of heated air, fire gases, and smoke directly above the involved fire area.

Front 21

Thermal Layering (of Gases)

Back 21

Outcome of combustion in a confined space in which gases tend to form into layers, according to temperature, with the hottest gases are found at the ceiling and the coolest gases at floor level.

Front 22

Trench Ventilation

Back 22

Defensive tactic that involves cutting an exit opening in the roof of a burning building, extending from one outside wall to the other, to create an opening at which a spreading fire may be cut off.

Front 23

Vertical Ventilation

Back 23

Ventilating at the highest point of a building through existing or created openings and channeling the contaminated atmosphere vertically within the structure and out the top. Done with holes in the roof, skylights, roof vents, or roof doors.

Front 24

Windward Side

Back 24

The side or direction from which the wind is blowing.

Front 25

three phenomenon of fire

Back 25

flashover, backdraft, and rollover

Front 26

efficient ventilation will:

Back 26

reduce water use, smoke and gases, heat, and increase visibilityreduces risk of bkdrft, flshvr... increase life safety

Front 27

white smoke, grey

Back 27

steam

Front 28

brown smoke

Back 28

wood

Front 29

black smoke

Back 29

unburned fuel, hydro carbon fire

Front 30

lapping

Back 30

extension of fire from a window to a story above it

Front 31

types of ventilation

Back 31

natural, mechanical, horizontal, vertical

Front 32

three roof types are

Back 32

arched, pitched and flat

Front 33

methods

Back 33

hydraulic, natural horizontal, positive-negative pressure, forced vertical/horizontal

Front 34

inspection cut

Back 34

building construction- depth, material type, etc

Front 35

indicator holecut

Back 35

see what th smoke is doing, 5 inch triangle. remove insulation

Front 36

ID cut

Back 36

firat cut to identify a rafter and create a heat hole

Front 37

distance between Beams

Back 37

12’-40’

Front 38

Light weight construction commercial roofs uses _____for structural support of roof

Back 38

beams, purlins, short rafters (sometimes not nailed in)

Front 39

PPV, blower should be set back __-__ feet

Back 39

four to ten

Front 40

fan cone to cover

Back 40

entire door

Front 41

tilt blower __-__degrees,

Back 41

20-30

Front 42

hydraulic ventilation involves holding the nozzle back __ ft from the window, with the fog pattern covering ___% of the open area

Back 42

2, 85-95

Front 43

7-9-8 cut is also called the

Back 43

coffin cut

Front 44

additional cuts made in ventilation holes to make it easier

Back 44

dicing

Front 45

Poor ventilation will contribute to

Back 45

mushrooming and fire spread

Front 46

Dark/black smoke is

Back 46

unburned fuel

Front 47

hot smoke and gases travel up until they are coold to the temp of the surrounding air, forming layers within the building

Back 47

stratifying effect

Front 48

High rise ventilation often requires the use of ___ for ventilation

Back 48

vertical passages, hvac, horizontal with mechanical devices

Front 49

basements and windowless building require the use of ____ ventilation

Back 49

mechanical

Front 50

need to ventilate is determined by what factors

Back 50

heat smoke and gas conditions in the structure, as well as the structural condition and life hazard

Front 51

basement fire ventilation should be directed

Back 51

away from the entry point

Front 52

creating pressure differentials in a stucture is

Back 52

positive pressure ventilation

Front 53

the size of ventilation entry and exit holes should be

Back 53

the same size

Front 54

Pos pressure fan should _____ cover the door

Back 54

completely

Front 55

high rise ventilation requires ___to ___ times the personnel

Back 55

four to six times

Front 56

disavantage of PPV is that it can introduce __ into the structure

Back 56

CO

Front 57

reasons for fireground ventilation include (6)

Back 57

life safety, fire attack and extinguishment, fire spread, reduction of flashover, " of backdraft, property conservation