Fire Safety Flashcards
What are the 7 main culprits of bad IAQ?
Combustibles VOCs Standing Moisture Formaldehyde Poisons Particle board
What are the 3 classes of standpipe? Describe them.
Class 1: equipped with 2.5 inch outlets. To be used by fire dept only. Dry system Class I (Dry Standpipe): used by fire department only. • Dry system without a directly connected water supply, 2.5” outlets, • Located at every level of a building within stairway enclosures or within the vestibule if exit enclosure is pressurized • Must be used when any portion of a building interior is more than 200 feet of travel from the nearest point of fire department access • Used in buildings with more than three stories, and shopping malls • If more than 75’ above grade, the pipe connection must be provided in every required stairway as well • Ball Drip used to insure the standpipe remains dry • Won’t freeze or rust Class 2: used by occupants before the fire department arrives • Wet system directly connected to water supply system • Equipped with 1.5” outlets and hoses for occupant use • Required in buildings 4 or more stories tall, theaters, assembly spaces, B, H, I, M, and S occupancies • Every point of the building must be within 30’ of the end of a 100’ hose attached to an outlet • Must be designed to supply at least 35 gpm at 25 psi for at least 30 minutes • Water system must be designed to provide 70 gpm at 25 psi for 30 minutes Class 3: used by both occupants and fire department • A combo system directly connected to a water supply with both 1.5” and 2.5”outlets • Installed in buildings where the highest floor level is more than 30’ above the lowest level of fire dept. access • Every point of the building must be within 30’ of the end of a 100’ hose attached to an outlet • Installed in buildings where the highest floor level is over 30’ above the lowest fire department vehicle access, or where the lowest floor level is 30’ below the highest fire department vehicle access • Exception to use a Class I Standpipe Are: • Buildings equipped with a sprinkler system • Open parking garages less than 150’ tall • Open parking garages subject to freezing temperatures • Basements that are sprinklered
Which of the following types of standpipe connection are intended for use by building occupants? A. Class I only B. Class II only C. Class I and Class II only D. Class II and Class III only
D Class II and Class III only
- Which electric feeder has highest total first cost, but lowest labor cost? a) Cable tray b) Wire and conduit c) Busduct d) Cablebus
c) Busduct
Where are fire detectors required?
Near fire doors, exit corridors, hotel rooms, bedrooms, public places of assembly
What are the types of fire detection devices?
Ionization detector: responds to products of combustion-ionized particles rather than smoke; photoelectric detectors: respond to smoke which obscures a light beam; rise of temperature detectors: responds to precense of heat and triggers when a temp is reached;
What is the principal advantage of dry- type transformer? a) Low voltage b) Ease of installation c) Low noise d) Small size
b) Ease of installation
True of false. Dry-pipe sprinkler systems are most efficient than wet-pipe systems/
false
True or false. Siamese connections serve both sprinklers and standpipes.
true
True or false. The hazard classification does not necessarily affect sprinkler layout.
false
True or false. Standpipes must be provided within stairways or within vestibules of smoke proof enclosures.
true
True or false. Standpipes are required in building four or more stories high and those exceeding 150 ft.
true
True or false. Sprinkler piping can be either copper or plastic.
true
The normal concentration of oxygen in air is:
21%
Evacuation and fire protection in high-rise buildings can be problematic because fire fighting equipment cannot usually reach higher than:
90 ft (27m)
Exterior fire escapes are generally no longer permitted because:
smoke plumes rising from exterior windows can redner these devices unusable early in a fire
n order of importance, it is most important to fire-protect:
columns, girders, beams, floor slab
CoGiBeFl
Supplying fresh air to a smoke-free stair entirely from the top or bottom is not advisable because:
It is too likely that open doors near the source would deplete fresh air for the rest of the stair
Sprinkler and smoke removal systems are sometimes at cross-purposes because:
the buaoncy of smoke is reduced by cooling water
In a reinforced-concrete building, reinforcing rods can be used as lightning conductors only if:
the rods are welded, not tied
What is a standard temperature for fusible link activation?
165 deg F is most comon
What are the 3 things a fire needs?
fuel source
high temperature
oxygen
Three common objectives of building fire safety, in order of usual importance are:
1 protection of life
2 protection of property
3 continuity of operation
Outline how occupant make decisions in a fire:
1 cues are detected (smell smoke, hear alarm bells)
2 occupant define situation (how serious is fire, how other people are reacting
3 coping behavior begins (fight or flight)
Fire passes through four stages in this order:
- Incipient: invisible particulate matter like combustion gas is given off but no flame is visible, nor any smoke/heat generated. Sensors detect gas
- Smoldering: large particles become visible as smoke, but no visible flame or appreciable heat. Sensors are photoelectric
- Flame: appreciable heat is not immediate present, but follows very quickly. Sensors detect flame
- Heat: uncontrolled heat and rapidly expanding air is present and flames and smoke become major hazards. Smoke inhalation ultimately causes most injuries. Sensors detect heat.
Active Smoke Control System:
an engineered system that uses mechanical fans to produce pressure differentials across smoke barriers or to establish airflows to limit and direct smoke movement
• Open doors with automatic closing devices close
• Supply and return air ducts to the fire zone shut down
• Exhaust to the outside air is turned on creating negative pressure
• In places or refuge, return an exhaust air ducts are closed and supply air is forced
into a space creating a positive pressure.
Compartmentation:
Critical, as it separates a building into sections
• Goal is to contain a fire and limit its spread so people can escape and to protect other parts of the building that weren’t originally subject to fire
• Can serve as an area of refuge for occupants
• Separation is required:
• Between different occupancies
• At Structural members, they are isolated to protect from fire exposure
• Depending on occupancy at walls, floors, and ceiling that separate compartments
(aka: spaces)
• At parts of the a building where the max allowable area is exceeded
• At all openings (e.g.: doors, windows, ducts) through rated walls, closed with
approved fire rated devices
• At exterior walls so to avoid fire spreading to other structures
Smokeproof Enclosure:
a required exit which consist of a vestibule and continuous stairway enclosed from the highest point to the lowest point by 2-Hour walls and which exist into a public way or exit passage leading to one
How do sprinkler systems hamper the functioning of smoke exhaust systems?
they create a curtain of water that inhibits the movement of smoke and it cools the smoke, thus reducing its bouoyancy. As less bouyant smoke descends, visibility is reduced and the danger of smoke inhalation increases. The buoyancy of smoke is the factor relied on by smoke exhaust systems, whose intakes are located at ceiling level.
Describe Class I standpipes
used for full scale fire fighting
typically required in both sprinklered and unsprinklered buildings more than 3 stories high, as well as in malls
used by firefighters only
2.5 inch hose connection
System of choice as the use of class I and II decline
Describe Class II standpipes
used for first aid fire fighting before fire stucks arrive
use 1.5 inch hose connection with hose, nozzle and hose rack
Describe Class III standpipes.
combine characteristic of both class I and II
Types: automatic wet, automatic dry, semi-automatic dry, manual dry, manual wet.
quick response sprinklers
required in all light hazard occupancies (hotels, motels, offices)
Response time index
response time index which indicates how fast the sprinkler can absorb heat from its surroundings sufficient to cause activation
early suppression fast response sprinklers:
recommended for specific high challenge fire hazards encountered in high pile strorage
operate at a high pressure and flow(50 psi minimum)
Fire Extinguishers:
- Type A: ordinary combustibles (paper, wood, cloth), contains water or water based agents
- Type B: flammable liquids (gas, paint, solvents), contains smothering types of chemicals (carbon dioxide, foam)
- Type C: electrical equipment, contains nonconductive agents
- Type ABC: all of the above
- Type D: combustible metals, matched with the fire they might be used on
Halon extinguisher:
used when water damage might be bad for the room (e.g.: computer rooms)
Foam extinguisher:
used where flammable liquid fires might occur (e.g.: industrial buildings,
aircraft hangers)
intumescent paint/calk/putty:
material expands rapidly when exposed to heat
insulating the surface
Sprinkler Head Types:
- Upright: sit on top of the pipe directly under the structure where combustion gases are likely to form
- Pendant: suspended under a pipe, typically seen in lay-in ceiling systems
- Sidewall: located in small rooms that usually only require one head
- Must be replaced, regardless of type, after being activated
- Glass Bulb Color/Temperature Code:
Preaction Systems:
• Reduce likelihood of a false start by requiring both a sprinkler head and fire
detection system to be activated
• Water is allowed into the system before a sprinkler head is opened
Deluge Systems:
- Used in high fire hazard areas to flood area in case of a fire
- Heads are always open and water is controlled by a sensor
- Sprinklers are activated all at once regardless of the location of the fire
Dry pipe System:
• Used in areas subject to freezing because no water sits in the pipes
• Hold valves closed with compressed air, requires constant pressure else the
system will leak
• Slower to deliver water if pipe runs are long
Wet pipe System
- Most common system
- Continually pressurized with water
- Have low initial cost
- Have quick response time, will work when a sprinkler head reaches 135 ̊F - 170 ̊F
- Susceptible to damage from freezing
Circulating closed loop systems
These wet pipe systems use the rather large sprinkler piping to ciruclate water for water source heat pumps. Water is not removed from the system, only circulated.
Advantages of mist sprinkler systems over water systems:
mist sprinklers emit less water, thus reducing water damage
mist also moves around obstructions more easily
What were the advatnages of halon extinguishers
no oxygen dusplacement, little harm to people, and no residue on computer equipment
Why was halon phased out as a fire extinguisher in 1994
the use of halon depleted earths ozone
What are the advanages of foam extinguishers?
foam can be used in areas where high velocity streams of water may damages delicate machinery
foam is effective in reducing a fire heat, and is effective at protecting structures from collapsing due to excessive temperatures
Advantages of CO2 extenguihers
provides cooling effect and smothering action
noncombustible and will not react to most substances
does not conduct electricity
will not normally damage electrical equipment
Disadvantages of foam extinguishers
conducts electricity, thus it shouldn’t be used for electrical fires
must be used in great quantities to be effective
Disadvantages of CO2 extinguishers
displaces oxygen (must be used in confined spaces where there are no people, spaces that that are not ventilated, ie raised floors or suspended ceilings)
Where would a clean agent extinguisher be used
confined and vital spaces such as control rooms, computer and communication facilities
3 techniques for lightning protection
frankin cone - mast with conductor runnogn straight to ground
overhead ground shield wire - grounded overhead shiled wire supported by two masts
faraday cage- conductive mesh surround conconductive mass
3 basic part to fire alarm system:
1 signal initiation
2 signal processing
3 alarm indication
Fire alarm
• Controls the detection, suppression, and notification of fire
• Alarms are wired to a central port, when a signal is received the system can
activate the fire suppression system and/or notify desired people
• Can integrate with security systems so normally secured doors can be
opened for a safe evacuation
• Can link to the electrical system to provide emergency lighting or elevator
capture during a fire/emergency
How are drawings for a fire sprinkler system of a retail building typically prepared?
The owner’s fire protection consultant prepares a set of criteria drawings per the owner’s requirements, and then a fire protection sub-contractor prepares the construction drawings based on them
or
A fire protection sub-contractor can prepare the entire construction drawing set as part of his design - build contract without the involvement of the owners fire protection consultant.
