Fire growth No sprinklers Fire growth Sprinklers present

Fire growth: No sprinklers

Fire growth: Sprinklers present Workbook Page 2

Why Fire Sprinklers? n n n 80% of fire deaths occur in the home Low probability, high consequence event Over 4, 000 people die each year in home fires $$$ millions in property damage Less than 2% of homes contain sprinklers

Residential sprinkler benefits Life safety

Residential sprinkler benefits Property safety Conservation Environmental impact FF safety. Housing density Demand on FD

Causes of house fires (%) 10 25 15 13 22 15

Who Is Most At Risk In A Fire? n n Sleeping occupants Small children and the elderly n Twice as likely to die as able-bodied adults

What Is Flashover? n When ceiling temp reaches ~1, 200° F: n n n Bottom of smoky layer erupts into flame Everything combustible ignites at once Can take as little as five minutes

Heat Spread by Convection

Heat Spread by Convection

Most victims in postflashover fires are remote from the room of origin

Residential Sprinklers & Demand on Resources n Water: n n Apparatus & personnel: n n 9 -12 GPM v. 200 GPM per line. Fewer critical tasks = fewer resources. Organization: n Can be EMS-oriented v. suppressionoriented.

Critical fireground task n n A task that must be performed simultaneously, or in a highly coordinated manner, with other tasks. Examples of critical tasks n n Attack line and ventilation Attack line and water supply

Critical Fireground Tasks Task Personnel Attack S&R Ventilation Backup line Safety Pump oper. Water supp. Command 2 2 1 2 1 1 Assignment 1 st engine Ladder Co. As assigned 2 nd engine As assigned Each engine 2 nd engine District chief

Sprinkler v. manual suppression n n 30 -90 seconds after flames 13 GPM @ 10 PSI Very little has burned Room of origin still tenable to life Operates automatically n n n 8 -15 minutes after report 200 GPM @ 100 PSI A lot has burned Entire home untenable to life Someone needs to call fire department

Sprinkler v. fire department n Sprinkler Operates whether you can take action or not n n Elderly, bedridden, children Operates whether you are there or not n Asleep, in another room, in yard, away n n Fire department Firefighters can’t respond until someone calls Fire can burn unnoticed until it breaks out of house

Why sprinklers? n n n Builders build safe homes – then people move in Houses don’t catch fire, contents do Contents loaded with synthetic material n n Burn twice as hot, twice as fast Homes are tight for energy

Why FD’s want sprinklers n Can’t respond in time to save lives n n n Content fires go to flashover in 5 minutes or less Occupants start dying halfway to flashover Occupants who can’t get out under own power twice as likely to die n The young, elderly

Smoke alarm limits n n In house fire where deaths occurred, over 40 percent of the homes had working smoke detectors Occupants often disable smoke alarms to prevent nuisance alarms

Sprinkler effectiveness n n Smoke detectors by themselves less than 50 % effective Smoke detectors + sprinklers increase survival rates to 97% n Based on long-term studies in Napa CA, Prince Georges County MD, Scottsdale AZ

Why sprinklers are effective n Quick acting (30 -60 seconds after flames visible) n n n Fire is small and containable Stop spread of smoke and flame before flashover Control fire with 10 -15 GPM v. 200 GPM from fire hose

Sprinkler experience n Zero lives lost in sprinklered homes n n n Scottsdale, AZ Napa, CA Prince George’s County, MD Property damage (including water damage) nine times less Fire departments handle with fewer stations and firefighters

Before 13 D n n NFPA 13 was the only standard Categorizes buildings by “hazard class” n n Fire load, rate of heat release, peak heat release Uses area v. density to determine water flow n As hazard class increases, density and coverage area increase n n Higher hazard = more GPM, more sprinklers Additional gallonage for fire hoses

NFPA 13 Area/Density curves

Density and area coverage n n Function of orifice size and pressure. Orifice size indicated by K factor. n n Examples - 3. 0, 3. 9, 4. 2, 5. 6. The higher the K factor, the larger the orifice.

Lower pressure = smaller area

Higher pressure = larger area

Use of higher pressure n n Sprinklers with the same orifice size can cover wider areas with the same density Reliable RES 16, 3. 0 K factor n n n 9 GPM over 12 x 12 area at 9 PSI 10 GPM over 14 x 14 area at 11. 1 PSI Both supply. 04 GPM per sq. foot

Use of larger orifices n Compared to a head with a smaller K factor, one with a larger K factor supplies a higher density to the same area. n n 3. 0 for 14 x 14 area flows 10 GPM at 11. 1 PSI. 3. 9 for 14 x 14 area flows 12 GPM at 9. 5 PSI.

Hydraulically most remote n The hydraulically most “demanding” n n At the minimum required flow, the sprinkler that causes the highest drop in pressure from the street Not the geographically most remote on gridded systems n Water enters grid at different points

NFPA 13 D Installation of Sprinkler Systems in One - and Two-Family Dwellings and Manufactured Homes

NFPA 13 D’s beginnings n “America Burning” published in 1973 n n n US leads in fire deaths. Most fire deaths occur in homes. NFPA 13 committee formed residential sub-committee to investigate sprinkler protection.

Format of 13 D n n n n 1 - General information. 2 - Water supply. 3 - System components. 4 - System design. 5 - Limited area dwellings. 6 - Referenced publications. App. A - Explanatory material App. B - Referenced publications.

13 D objectives n n n Limit maximum ceiling temp to 600°F. Limit temp at 5’ 3” to 200°F. Prevent flashover and keep room of origin tenable to life for 10 minutes. Attain objectives with no more than two sprinklers operating, with density of. 04 GPM/sq. foot. No minimum area requirement.

Committee recommendations n n n System can be slightly less reliable, with fewer operational features, and be effective Must be substantially less expensive Primary goal: life safety Secondary goal: property safety Should control fire for sufficient escape time – 10 minutes

Recommendations n n n Piping, components, hangers must be compatible with residential construction techniques Combined sprinkler/plumbing systems are acceptable from a fire protection standpoint Sprinklers can be omitted in areas of low incidence of fire deaths

First edition of 13 D in 1975 n n n Based on relatively limited scientific understanding of residential fires and how sprinklers should protect against them Applied technology that was applicable to property protection or commercial, industrial occupancies Was not cost-effective but spurred research and development

Full scale tests n n n Discharge rates Spray patterns Response sensitivity Design criteria Ability to maintain tenability to life for escape time

Goal: Tenability in room of origin n Carbon monoxide concentration n n Temperature at breathing level n n 3000 PPM 200°F Oxygen depletion

1980 edition n Based on better understanding of residential fires Had a new class of sprinkler Based on different method for calculating minimum water flow

Criteria for residential sprinklers n Prevent flashover. n n Maintain 200 o. F at eye level n n n Turning point in fire for victims, firefighters Temperature is survivable near the floor 150 o. F of moist air will prevent breathing Control fire with one or two sprinklers n Allows smaller water supply

Sprinkler incentives n n n Narrower streets Smaller setbacks Smaller water mains Fewer fire hydrants Fewer fire stations

WHAT LIES AHEAD

10 -20 GPM v. 200 GPM

Fire threat, 1 -2 family homes n n n Sleeping occupants Small children, elderly and no special exit arrangements Cooking facilities Smoking Unprotected vertical openings

House fires n n A low probability event, but a highconsequence event A reasonably expected risk in this community

Flashover is the enemy n n n Flashover - all exposed surfaces in room ignite almost simultaneously Flashover description - flames out the door of room of origin Time to flashover dictated by rate of heat release n Synthetics burn twice as hot, twice as fast

Time to flashover n n Measured from time of flaming stage A large portion of fires go to flaming stage quickly Smoldering stage nearly always progresses to flaming May not produce much hot smoke until shortly before flaming

Fire cause and time to flashover n n n Unattended cooking (25 -30 %) Playing with matches (13 %) Arson (15%) Smoldering cigarette (20 -25%) Heating (15%) Electrical (10 -12%) Very quickly Minutes-hour

Most victims in postflashover fires are remote from the room of origin

Home fires by victim location & extent of flame damage

Residential Sprinkler Characteristics n n Fast response n 30 -60 seconds v. 120 -180 seconds for commercial sprinklers Discharge pattern n Hits wall at 12” below ceiling Prevents flashover in room of origin Reduces number of critical fireground tasks

… characteristics. n n Responds before room of origin becomes untenable to human life Tenability: o n Eye-level temp > 150 F, moist air n CO > 3000 ppm n Smoke >. 5 Optical Density/m

House fire at 4842 Oak Street n n Two-story home Fire in kitchen Source - Electric heater Material ignited - synthetic-lined drapes, spread to cabinets and cupboards

Residential fires n n n 23 % of fires 80 % of fire deaths 75 % of fire injuries

Events after discovery n n n Family sleeping in upstairs bedrooms Parents awakened (maybe smoke alarm). Mother saw incipient fire, called 911 Smoke, heat blocked mother from returning upstairs, she escaped through front door Father rescued two sons, could not reach third One fatality, four injured

Fire growth n Flashover occurred 4 minutes after flaming stage n n n Untenable in 2 minutes Fire department arrived 4 -5 minutes after call Victim died of CO poisoning

Witness statements confirm model results n Mother’s description n n Saw curtains on fire Grabbed extinguisher, fire too large Went to living room to call 911 Tried to go back upstairs, stopped by smoke/heat Neighboring firefighter’s description n n Saw fire in kitchen as he started across street In seconds, flames were out front door

If sprinklers had been installed No sprinkler n n Untenability in 123 seconds (smoke, heat, O 2) Flashover in 4 minutes, 8 seconds Sprinkler present n n n Sprinkler operated in 68 seconds Ceiling temp = 250 F Not enough smoke, heat, CO to make room untenable