Chpt 4 Flashcards
Stairs that are not part of the means of egress are often referred to as
Convenience stairs
In buildings four or more stories in height, ____ is generally required to extend to the roof unless the slope of the roof is especially steep
One stairway
A key component is the step itself, which consists of the tread and the riser, commonly referred to as the
Run and rise
Extend in a straight line for their entire length
Straight run stairs
Have an intermediate landing between floors and reverse direction at that point.
Return stairs
Are two separate sets of stairs constructed in a common shaft
Scissor stairs
This type of stair design is common in modern construction
Return stairs
Are often found as grand stairs or convenience stairs serving two levels
Circular stairs
Are typically found in dwellings where they are used to provide access to an attic space that does not have permanent access stair.
Folding stairs
Consist of a series of steps spiraling around a single column
Spiral stairs
Because protecting the stairwell from the products of combustion is extremely important, building codes require a high level of protection for most stairs used as a
Means of egress
Generally, ____ are required to be separated from the rest of the building
Stair enclosures
As defined by codes, ____ are exterior to a building and are open to the air.
Exterior stairs
Are open metal stairs and landings attached to the outside of a building
Fire escapes
Are usually anchored to the building and are not supported at ground level
Fire escapes
Building codes have traditionally required a minimum of one _____ for stairs serving buildings five stories or higher, and more recently, stairs serving floor levels more than 30 feet below the level of exit discharge.
Smoke proof enclosure
Stair enclosures may be classified as ____ using either active or passive smoke control.
Smokeproof
Typically, _____ are on the exterior perimeter of the building and are entered through ventilated vestibules or open balconies
Smokeproof stair enclosures
A common alternative approach over the past 25 years to provide a smokeproof enclosure is to pressurize stairwells when the building is in
Fire mode
Activated by automatic fire smoke detection equipment, a dedicated mechanical air handling system is designed to keep smoke out of the stair enclosure by
Pressurizing the shaft
Is a hoisting and lowering mechanism equipped with a car or platform that moves in guide rails and serves two or more levels or landings
Elevator
Is another term used to describe elevators and often defines as a passenger elevator that has been designed to carry freight
Service elevator
Electric elevators are subdivided into either
Drum or traction devices
Older style elevators employ a drum on which the hoisting cable is wound
Drum elevators
The most common type of elevator in buildings over six stories is the traction elevator because it is very fast and does not have the height limitations of either hydraulic or drum type elevators
Traction elevators
Is an electric switch designed to stop the car by removing power before it reaches the upper or lower limits of the hoistway
Terminal device
Are large springs or hydraulic cylinders and pistons located at the bottom of the pit that act as shock absorbers should the terminal switch fail.
Buffers
Buffers cannot safely stop a free falling car. They can only stop one traveling at its
Normal rate of speed
Is also known as the speed governor. This switch slows the drive motor when an elevator starts to exceed a safe speed. If the car continues to accelerate, it applies the car safeties and trips the over speed switch.
Speed reducing switch
Is also connected to the speed governor. This switch is activated of the speed reducing switch fails to slow the car sufficiently.
Over speed switch
Are tapered sets of steel jaws that wedge against the guide rails and bring the elevator to a stop.
Car safeties
Elevator safeties are designed to stop a
Free falling car
An ____ is the vertical shaft in which the elevator car travels and includes the elevator pit .
Elevator hoistways
Elevator hoistway enclosures usually are required to be a fire rated assembly with a _____
1 to 2 hour rating
Penetrations through the hoistway walls are protected by the installation of an appropriately rated assembly such as a listed and labeled
Door and frame
present a potential for acting as a vertical chimney to spread fire and smoke throughout a building
Hoistways
To prevent mushrooming, building codes require venting at the ____ of practically every hoistway built today
Top
Single elevator hoistways that only serves upper levels have____ for rescue purposes every three floors or so in that portion without normal hoistways doors
Access doors
In very tall buildings, elevators are divided into zones, with one zone serving the lower floors and another zone serving upper floors. A zone usually serves
15 to 20 floors
Are used for express elevators that serve the upper elevators zones in tall buildings
Blind hoistways
Passenger elevator car doors are powered by an electric motor mounted on the
Top of the elevator car
On hydraulic elevators a top exit may or not be provided depending on whether the system is equipped with a
Manual Lowering valve
A ___ is provided on all electric traction elevators
Top exit
In multiple elevator hoistways, most elevator cars are equipped with _____to allow passengers to be transferred and laterally from a stalled car to a functioning car next to it
Side exits
Commonly called escalators, are stairways with electrically powered steps that move continuously in One Direction
Moving stairs
Vertical opening protection also can be provided by a ____at the top of the escalator
Rolling shutter
The most common method to protecting the vertical opening is to use closely spaced ______ around the opening
Sprinklers in conjunction with draft stops
Are similar to escalators but are only used to move people horizontally or a slight inclines
Moving walkways
Are often found in airports to move occupants long distances between the main terminal and remote concourses
Moving walkways
Is typically found in manufacturing or storage occupancies and is used to transport items and materials
Conveyor system
A primary concern for conveyor penetrations during a fire is incomplete
Door or shutter closure
Also include stairways and elevator and dumbwaiter hoistways
Vertical shafts
Is a term generally applied to the vertical pathway in a building that contains utility services
Utility chase
It is usually not practical to provide any horizontal fire barrier along the length of the
Shaft
Is a type of utility cheese used to contain piping needed for building services such as hot and cold potable water, drain lines, steam, hot and chilled water for heating and air-conditioning, and sprinkler piping
Pipe chase
Provides for the removal of trash and garbage from upper floor of building such as residential properties
Refuse chute
Refuse chutes are required to be constructed of
Non combustible material with rated doors
A fire in a properly designed, installed, and maintained Refuse or laundry chute should be contained within the
Chute
Is installed as part of an exhaust system for commercial cooking appliances that produce grease laden vapors
Grease duct
Typically, ____ are installed over deep fat fryers and grills
Grease ducts
Are provided in building primarily to maintain a comfortable environment for occupants
HVAC systems
Systems that make use of water as the heat transfer medium are known as
Hydronic systems
However, many HVAC systems involve the distribution of conditioned air through a building from one or more mechanical equipment rooms. Such systems are generally known as
Forced air systems
Is the air distribution component of the HVAC system
Air ducts
Sometimes _____ the space between a suspended ceiling and the roof deck are used as a return air plenum
Interstitial spaces
Experienced firefighters know that when a fire occurs in any building, fire control and occupant safety are in enhanced by
Venting the products of combustion to the outside by the shortest route
Means the use of mechanical equipment to produce pressure differences across smoke barriers to inhibit smoke movement
Smoke control
Automatic transfer of an hvac system to ____ can be accomplished by smoke detectors serving the various floors of the building
Fire operation
Automatic initiation of _____ in an hvac system must always take priority over the normal system functions
Fire operation
When a system has both a manual and automatic capability, the ____ shall take priority over the automatic control
Manual
A ____ is a type of smokeproof enclosure that makes use of a vestibule between the corridor and the stairwell that is open to the atmosphere
Smokeproof tower
Utilizes a blower or fan to provide a slightly greater pressure in the stairwell then the Corridor to prevent the infiltration of smoke from the Corridor into the stairwell
Pressurized stairwell
There are two general design methods used for pressurized stairwells. One method is to have a fan supply air to a stairwell at a single point. This is known as the
Single injection method
To overcome the possible limitations of a single injection system, a____ can be used
Multiple injection system
In a ____ an air supply shaft runs parallel to the stairwell from the supply fan. Air discharge point into the stairwell are located at several points along the stairwell. This method providing more uniform flow of air into the stairwell.
Multiple injection system
In a________, the airflow into the stairwell can be adjusted depending on the number of doors that may be open
Compensated system
A ________ can adjust the pressure in the stairwell either by modulating the air supply or through over pressure relief
Compensating system
Over pressure relief in the stairwell is accomplished through the use of______ that open to the outside, thus relieving the pressure buildup in the stairwell
Dampers
The simplest means of controlling the exhaust dampers is to use dampers with
Adjustable counterweights
can be provided in the roofs of buildings to permit the release of smoke and heat from the fire.
Vents
have spring operated opening mechanisms that can be released by a fusible link or other automatic detectors, including smoke detectors
Vents with metal lids
Are used in conjunction with smoke vents to increase their effectiveness
Curtain boards
The ____ reduce the dissipation of the heated air currents from a fire and increase the speed of operation of the vents
Curtain boards
The depth of a curtain board will vary depending on the nature of the hazards within an occupancy, but should be not less than
20 percent of the ceiling height
Curtain boards should be spaced so that they are not farther apart than ___ the ceiling height
8 times
Roof vents in the sprinkler building may be a maximum value in removing products of combustion during the final or
Overhaul stages of fire
Are used to convert high-voltage electricity, as supplied by the electrical utility service, to an appropriate voltage for use in the building
Transformers
Air cooled transformers, also called______, use the surrounding air to cool the unit through fins and heat sinks installed on the body of the transformer
Dry transformers
Contain oil to conduct heat away from the core and also to electrically insulate internal components from arcing
Oil cooled or oil filled transformers
Because the oil also provides electrical insulation, it must have _____ properties
Dielectric
Are typically engine driven, using a gasoline, diesel, or natural gas internal combustion engine.
Generator
The ____ is the most common type because gasoline is more hazardous and natural gas may be subject to outages at the same time as the electrical power distribution system
Diesel fuel engine generator
At a minimum, the _____will need to supply the required life safety systems plus critical needs of the occupancy
Generator
Emergency power supplies that require batteries commonly use
Lead acid type storage batteries
Also releases flammable hydrogen gas during battery charging and also during contact with some metals
Sulfuric acid in lead acid batteries
