AE202 Ch 4

Fire Protection Statistics

pinpoint problems; formulate solutions

Fire Protection Objectives

prevent life loss, injuries, and property damage; continuity of operation

Why are the statistics for U.S. worse than more crowded countries?

wood construction; "American Dream" is to move to the suburbs with just family - no neighbors to help alert in times of fires

Reported Fires by Year Trend

decreased by 1/2

Civilian Fire Deaths by Year Trend

decreased

Estimated Fire Property Loss by Year Trend

no change

Population-Based Fire and Civilian Fire Death Rates Trends

total fires decreased; home fires decreased

Civilian Fire Deaths per million Population Trend

decreased

Fires per thousand Population by Size of Community Trend

decreased below national rate (4.5)

Fire Deaths by Incident Type in U.S. Trends

1. structure

2. home structure

3. vehicle

all decreasing

Average Loss per Structure Fire Trend

growing trend (more expensive to build)

Deaths per 10,000 Reported Home Fires Trend

homes remain unchanged

apartments decreased due to neighbors helping neighbors

Beverly Hills Supper Club

-165 deaths

-delayed alarm (alarm didn't exist)

-inadequate exits (locked doors)

-overcrowding

-rapid fire spread (wood construction)

MGM Grand

-85 deaths

-improper electric wiring

-rapid fire and smoke spread (holes in staircase)

-improper protection of vertical openings

-improper enclosed exits

-distribution of smoke by air handling equipment (smoke went to hotel rooms)

Station Night Club

-100 deaths

-many exit through the entrance

-occupants unaware of other exits

-over maximum capacity

-acoustic insulation gave off toxic smoke

Brunswick Building

-6 deaths

-no fire alarm system

-smoke in staircase

Residential fire account for __% of casualties

40

What age groups make up the majority of casualties?

0-9, >60

Percent of casualties by time of day

Noon - 4PM = 9.3%

4PM - 8PM = 9.2%

8PM - Midnight = 12.8%

Midnight - 4AM = 36.8%

4AM - 8AM = 19.2%

8AM - Noon = 12.5%

Causes of death

Asphyxiation = 74%

Burns = 24%

Mechanical Injuries = 2%

Heart Attacks = 0.5%

What are the conclusions to save lives?

-Early warning

-Smoke detectors and alarms

-Public awareness

-Careful with smoking materials

Combustion is a continuous reaction of what?

a fuel (reducing agent) with oxygen (oxidizing agent)

2 Modes of Combustion

1. Non-flaming

2. Flaming

Non-flaming Combustion

-glowing and deep-seated embers

-fuel is in the form of incandescent solid

Flaming Combustion

-high burning rates including explosion

-fuel is in the for of vapor (smoke)

Methods of Extinguishing

1. Cooling

2. Heat Removal

3. Volumetric Expansion

4. Fire Extinguisher

5. Oxygen Dilution

6. Fuel Removal

7. Chemical Flame Inhibition

Cooling Extinguishing

- water, straight hose (hose stream too forceful)

Heat Removal Extinguishing

-sensible heat (1 BTU/°F*lb)

-latent heat (970 BTU/lb)

Volumetric Expansion Extinguishing

-water displaces oxygen (2500:1)

-water stream can induce ventilation (used during firefighting)

Fire Extinguisher

-addition of surfactants, alkali carbonate

-retards run off

-prolongs soaking

Oxygen Dilution Extinguishing

-air is 20.9% oxygen so

-water/steam or CO2 can dilute the oxygen

Fuel Removal Extinguishing

-limit combustibles in the building

-fire loading

Chemical Flame Inhibition Extinguishing

-apply to flaming mode only

-puts our glowing fire only after long periods of exposure

-Halon 1301 CBrF3 ties up O, OH, H

-close doors, damper duct openings to develop concentration level

6 Stages of Fire

1. Overheat

2. Ignition

3. Established Burning

4. Sustained Burning

5. Flame at Ceiling

6. Full Roof Involvement (flash-over)

Overheat

-heat energy decomposes a fuel volatilize the gasses

Ignition

-ignitable fuel

-source of heat is sufficient to initiate combustion

-heat flux intensity and duration

-combination of heat flux and fuel

Established Burning

-a 10-inch flame (feedback changes from conductive and convective to radiative)

Sustained Burning

-6-foot-tall flame (one stuffed chair)

Flame at Ceiling

-flame is two stuffed chairs tall

Full Room Involvement (flash-over)

-everything is burning

Are thermal (flame & heat) or non-thermal (smoke & gasses) more dangerous?

non-thermal

Fire growth potential hazards

-fuel

-ignitability

-thermal inertia

-surface roughness

-thickness

-surface area

Automatic suppression

-contain fire to room of origin

Manual suppression

-by occupants

-depends on immediate detection

Barrier effectiveness

-Containment of fire for a period of time

-UL rating assembly

-Opening protection

-Fire Rated Doors

-Fire dampers

-Fusible links

Structural Frame Analysis

-supports barriers

-failure due to deflection/collapse

-U.L. rating

Smoke Movement Analysis

-the fire

-the building

-HVAC operation

-the forces

HVAC Operation

-dilution

-pressurization

-exhaust (smoke purge)

People protection - life safety

-location of fire

-location of people

-physical and mental limitations

-egress

Codes

-constantly changing

-MINIMUM REQUIREMENTS established by society or insurance carriers for the level of risk they are willing to accept

Building Codes

-provide sound and progressive construction practices

-minimum requirements

-don't cover everything

AHJ (Authority Having Jurisdiction)

Zoning Codes

-regulates type and size of buildings in specific area of municipality

-protects property value

-result of land use planning

Federal Regulations

-OSHA = work place

-HUD

-Farmer's home

Nearby State Codes

-PA

-NY

Nearby Local Codes

-NYC

-Philadelphia

-Pittsburgh

-Washington D.C.

Model Codes

-written by model code organizations

-adopted by municipalities

-updated every few years

International Code Council (ICC)

an international association that creates standards and codes for buildings

Standards (how-to-codes)

National Fire Protection Association (NFPA)

-NFPA - 13 = Sprinklers

-NFPA - 14 = Standpipes

-NFPA - 101 = Life Safety

International Building Code (IBC)

code that is dedicated to providing safety regulations for life safety, structural, and fire protection issues that occur throughout the life of a building

What are the height and area modifications regarding implementation of automatic sprinklers?

height is increased by 20 feet

max number of stories increases by 1 story

(200% increase in area)

Name the fire-rated walls that are most and least produced and sold.

MOST - 2hr or 3hr

LEAST - 4hr (most expensive, not necessary for building)

Means of Egress

Exit Access

Exit (stair)

Exit Discharge

Exit Access

corridor leading to an exit

Exit (stair)

temporarily as safe as outside

Exit Discharge

between the termination of an exit and a public way (door to the outside)

Max occupancy with one means of egress

50

Max length of exit access

200 ft, 300 ft with sprinklers

Average person can walk this distance holding their breath

100 ft

Max length of exit access in a dead-end corridor

20 ft, 50 ft with sprinklers

Area of Refuge

30"x48" floor area a wheelchair

in an enclosed stair or smoke component

1 for each 200 occupants

two-way communication to a central control point or public phone

Door widths

minimum 32" clear (36" door)

Door swings

- Shall not reduce the required exit width by one half during the course of the swing

- Shall not project more than 7" into the required width

Exit signs

5 ft candles

illuminated at all times

90 mins battery of generator

6" high letters

2" wide letters, except for "I"

3/4" wide spacing

Emergency lighting

1 ft candle minimum

illuminated when primary power source fails

90 mins battery of generator

Where does the emergency lighting illuminate?

aisles in rooms and space requiring 2 exits

passageways

exit access corridors

exits

exit discharge

Stair requirements

minimum 4' wide

4" - 7" riser

minimum 11" tread

uniform in size - 3/8" variation max

Water for Fire Suppression

low cost

available

removes 970 BTU/lb to vaporize

volumetric expansion

Types of Water Supression

standpipe - distributes water where needed

sprinkler - detect, notify, and apply agent (water)

First aid hoses purpose

used by occupants until fire department arrival (1 1/2")

Second aid hoses and valves purpose

firemen use (2 1/2")

used when exterior windows can't open

brings water into building where it's needed

Where are standpipes required?

- top floor is >30 ft above fire departments vehicle access

- any area within the building is >400 ft from a hydrant

Wet Standpipe

water pressure maintained at all times

Dry Standpipe

permanent water connection does not exist

not recommended

IBC pipe dimensions

building >75ft (6 stories) = 4"

building >150ft (12 stories) = 6"

Class I Standpipe

fire department use only

Class II Standpipe

occupant use

Class III Standpipe

fire department and occupant use

Flow Requirements

1 standpipe = 500 GPM (100 garden hoses)

2 standpipes = 750 GPM

3 standpipes = 1000 GPM

9 standpipes = 2500 GPM (max)

first standpipe = 500 GPM, additional standpipes = 250

Siamese Connection

fire department connection (FDC)

-must be labeled and visible

-18" 42" above grade

Components of a standpipe

2 sources (water supply + FDC)

check valves (prevent water from exiting at FDC)

auto ball drip (prevents freezing)

hose racks

risers

supply piping

fire pumps

Controlling pressure process

- water main = 30 psi

- jockey pump must pump up pressure to achiever 100psi at the test station (roof)

- reduce pressure to 85 psi on each floor

Static Pressure Reading

- read the gauge closest to the building while gauge 2 is closed

Residual Pressure Reading

- read the pressure at gauge 1

- measure velocity pressure at gauge 2, convert to GPM

Pressure Calculations

BHP = QP/1710E

- BHP = fire pump horsepower

- Q flow = GPM

- P = pressure (psi)

- E = efficiency (50-75%)

Sprinkler system objectives

control fires

notify fire department and occupants

Sprinkler system components

supply system

post indicator valve

backflow preventer (double-check valve)

Miscellaneous requirements

branch on each floor

FA required of system with 12+ heads

Flow switch

detects flow

connected to FA system

Tamper switch

keep OS&Y valve open

connected to FA system

Sprinkler systems piping network

supply main

cross main

branch piping - 8 heads max

black iron

copper

screw fittings

mechanical fittings