Essentials of Fire Fighting (4th Edition)
Chapter 10 Terms
Ventilation
Cockloft
Concealed space between the top floor and the roof of a structure.
Convection
Transfer of heat by the movement of fluids or gases; usually in an upward direction.
Forced Ventilation
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.
Gabled Roof
Style of pitched roof with square ends in which the end walls of the building form triangular areas beneath the roof.
Horizontal Ventilation
Any technique by which heat, smoke, and other products of combustion are channeled out of a structure by way of existing or created horizontal openings such as windows, doors, or other holes in walls.
Lapping
Means by which fire spreads vertically from floor to floor in a multistory building. Fire issuing from a window laps up the outside of the building and enters the floor(s) above, usually through the windows.
Leeward
Protected side; the direction opposite from which the wind is blowing. Also called Lee.
Mechanical Ventilation
Any means other than natural ventilation. This type of ventilation may involve the use of fans, blowers, smoke ejectors, and fire streams. Also called Forced Ventilation.
Monitor
Rectangular projection through roofs with metal, glass, or louvered sides. The sides are counterweighted, hinged, and designed to stay in place when held shut with a fusible link. Monitors are designed to ventilate an area when heat fuses the link.
Mushrooming
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.
Natural Ventilation
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.
Negative Pressure Ventilation
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.
Parapet
(1) Extension of the exterior walls above the roof. (2) Any required fire walls surrounding or dividing a roof or surrounding roof openings such as light/ ventilation shafts.
Point Of Entry
Point at which entrance is made into a structure.
Positive Pressure Ventilation
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.
Scuttle Hatch
Openings in the ceilings or roofs of buildings; fitted with removable covers for the purpose of providing access and ventilation to the cockloft or roof.
Sounding
Process of testing structural integrity of a roof or floor of a building, or of locating underlying supporting members, by striking the surface of the assembly with the blunt end of a hand tool.
Stack Effect
(1) Air or smoke movement through a building. Simply stated, cool air enters the lower levels of a building, and warm air within the building rises to the upper levels. (2) Tendency of any vertical shaft within a tall building to act as a chimney or "smokestack" by channeling heat, smoke, and other products of combustion upward due to convection.
Stratification
Settling of smoke at various vertical levels of accumulations or layers according to density of weight, the heaviest on the bottom.
Trench Ventilation
Strip or trench ventilation is the process of opening a roof area the width of the building with an opening 2 foot wide to channel out fire and heat.
Ventilation
Systematic removal of heated air, smoke, and/or gases from a structure and replacing them with cooler and/or fresher air to reduce damage and to facilitate fire fighting operations.
Vertical Ventilation
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. Also called Top Ventilation.
Windward
Side of the building the wind is striking.