Ch 14 Special Vent Operations Flashcards
These elevators serve the lower floors of the building
Low rise elevators
These elevators serve only those floors between the low rise and high-rise elevators
Mid rise elevators
These elevators serve only in the upper floors
High rise elevators
These elevators usually serve on the ground floor and the upper most floor of the building
Express elevators
These elevators serve some or all floors
Freight elevators
Fire behavior in high-rise buildings is most affected by _____ and ______
Stack effect, mushrooming
__________. Tendency of heat, smoke, and other products of combustion to rise until the encounter a horizontal obstruction
Mushrooming
________ . Formation of smoke into layers as a result of differences in density with respect to height with low density layers on the top and high density layers on the bottom
Stratification
Most PPV blowers positioned at street level are effective up to about _______ floors
22
One of the most direct means of moving personnel and equipment to the roof of a high-rise building when weather and smoke conditions permit is through the use of ______
Helicopters
In a closed compartment, the point where the interior pressure is equal to the pressure outside the space is called the__________
Neutral pressure plane
The standard that provides guidelines for the design and installation of smoke and heat venting equipment, NFPA ______, standard for smoke and heat venting, recommends using Automatic heat activated roof vents and curtain boards
204
___________ also known as draft curtains, are fire resistive half walls that extend down from the underside of the roof
Curtain boards
Curtain boards, also known as draft curtains, or fire resistive half walls that extend down from the underside of the roof. They generally extend a distance equal to at least_______ of the vertical distance from the floor to the roof but not lower than ________ above the floor
20 percent, 10 feet
The function of curtain boards is to limit the_______ spread of heat and smoke by confining it to a relatively small area directly above its source
Horizontal
________ is the natural vertical movement of heat and smoke in tall structures
Stack effect
Assuming that the structure is closed, with little or no gas is being vented to the atmosphere, a neutral pressure plane exist at the level of ambient atmospheric pressure usually between 35 and______ percent of the building height
50
Some windowless buildings have various forms of _______ glass walls that admit light but are of little value for tactical ventilation
Translucent
It is SOP in many fire departments to attack high-rise fires from the _____ and to concentrate relief crews and spare equipment on the staging floor, ______ below the fire floor
Floor below the fire, two floors
Some fire departments allow their firefighters to use ______ to ascend partway to the fire floor and to transport additional equipment when it is deemed safe to do so by the incident commander
Freight elevators
A fully equipped fire fighter, especially one wearing a full toolbelt and carrying spare air tanks, can weigh more than _______
300 pounds
If it is hotter inside than outside, the airflow will be inward at the bottom and outward at the top. But if the outside air is hotter than the air inside, the flow will be reversed. This is known as _______ 
Reverse stack effect
Aldo referred to as ceiling jets in technical literature. Firefighters have long called this phenomenon _____
Mushrooming
_______&________ often provides the best means of protecting the occupants of high-rise buildings
Aggressive ventilation, fire attack
_________ can prevent or reduce mushrooming on the upper floors and does not promote lapping, which is always a danger when horizontally venting multistory buildings below the top floor
Top ventilation
________ are the preferred method of roof access in high-rise structures
Aerial devices
Wind also influences the stack effect by raising or lowering the neutral pressure plane. _______ pressure causes the neutral pressure plane to rise, and ______ pressure causes it to fall
Positive wind, negative
Positive pressure ventilation may have to be supplemented if the fire floor is above the ________ floor
22nd
Ventilating above the fire floor will be most effective if the process is started at the __________
Top of the building
______&_____ are most common in large buildings having wide, undivided expenses of floor space
Roof vents, curtain boards
_________ are intended to limit the spread of fire within a building by releasing heat and smoke to the outside before the fire mushrooms throughout the building
Automatic roof vents
________ prevent smoke from spreading to other areas of the structure through the HVAC system
Smoke dampers
Curtain boards, also known as ______, are fire resistive half walls that extend down from the underside of the roof
Draft curtains
The function of curtain boards is to limit the horizontal spread of heat and smoke by confining it to a relatively small area directly above its source. They also concentrate heat and smoke directly under _______ to accelerate their actuation
Automatic roof vents
Usually, but not always, ______have no windows and ______ have small windows between grade level and the first floor of the building
Cellars , basements
As is true in other types of buildings, the greatest number of lives can often be saved in high-rise fires by an _______
Aggressive fire attack
If a high-rise building is opened at the roof and at street level, the direction and intensity of airflow within the building depends primarily on the________
Relative temperature differences
