Publisher’s version / Version de l'éditeur:
Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.
Questions? Contact the NRC Publications Archive team at
PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information.
https://publications-cnrc.canada.ca/fra/droits
L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.
Paper (National Research Council of Canada. Division of Building Research); no.
DBR-P-1208, 1983-11
READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE. https://nrc-publications.canada.ca/eng/copyright
NRC Publications Archive Record / Notice des Archives des publications du CNRC :
https://nrc-publications.canada.ca/eng/view/object/?id=382d6a68-8930-43fd-9482-231edaecb0e4
https://publications-cnrc.canada.ca/fra/voir/objet/?id=382d6a68-8930-43fd-9482-231edaecb0e4
NRC Publications Archive
Archives des publications du CNRC
This publication could be one of several versions: author’s original, accepted manuscript or the publisher’s version. / La version de cette publication peut être l’une des suivantes : la version prépublication de l’auteur, la version acceptée du manuscrit ou la version de l’éditeur.
For the publisher’s version, please access the DOI link below./ Pour consulter la version de l’éditeur, utilisez le lien DOI ci-dessous.
https://doi.org/10.4224/40001790
Access and use of this website and the material on it are subject to the Terms and Conditions set forth at
An assessment of the performance of automatic sprinkler systems
Richardson, J. K.
Ser
1
THI
n21d
National
Research
Conseil national
0. 1208
$
Council Canada
de recherches Canada
c . 2BLDG
--A N ASSESSMENT OF THE PERFORMANCE OF
AUTOMATIC SPRINKLER SYSTEMS
by J.K. Richardson
ANALYZED
Appeared in
Fire Technology
Vol. 19, No. 4, November 1983
p.
275
-
279
Reprinted with permission
I
DBR Paper No. 1208
Division of Building Research
La p r ' e s e n t e ' e t u d e Q v a l u e t r o i s i m p o r t a n t e s s o u r c e s d e s t a t i s t i q u e s s u r l a p e r f o r m a n c e d e s r 6 s e a u x d ' e x t i n c t e u r s a u t o m a t i q u e s 2 e a u e t a n a l y s e l e s r a i s o n s d e s p a n n e s q u ' i l s s u b i s s e n t . On y p r o p o s e C g a l e m e n t c e r t a i n e s m 6 t h o d e s v i s a n t 2 r s d u i r e l a fr'equence d e c e s p a n n e s . L e s m o d i f i c a t i o n s a i n s i p r o p o s s e s d e v r a i e n t p e r m e t t r e d ' o b t e n i r u n r e n d e m e n t s a t i s f a i s a n t d a n s p l u s d e 99% d e s c a s . Une e t u d e d e l a d o c u m e n t a t i o n s u r l e s e s s a i s d e c o m b u s t i o n e n v r a i e g r a n d e u r r ' e v P l e q u e l e s r ' e s e a u x d ' e x t i n c t e u r s a u t o m a t i q u e s 2 e a u o f f r e n t u n e p r o t e c t i o n q u i r e u s s i t 5 m a i n t e n i r La temp'erature d e s Cl'ements d ' o s s a t u r e a u - d e s s o u s d u n i v e a u s u s c e p t i b l e d e c a u s e r d e s dommages Q l a s t r u c t u r e .
Technical
Notes
AN ASSESSMENT OF THE PERFORMANCE OF AUTOMATIC SPRINKLER S Y m M S
J. Kenneth Richardson, P.E. According to recent reports.' the reli-
ability of automatic sprinkler systems varies between 80 percent and 99 per- cent. This variation has confused efforts to determine the performance level that can be reasonably expected from such systems.
To assess sprinkler system reliability, statistical data on system performance in building fires were reviewed. The data were taken from the following sources:
Automatic Sprinkler Performance Tables. 1970 Edition. Fire Journal. VoL
74, No. 3 (May 1980).
Automatic Sprinkler Performance in Australia and New Zealand. 1886- 1968.
Australian Fire Protection Association. Sprinkler Experience in High-Rise Buildings. 1969-1979. New York Board
is achieved if
the
system extinguishesthe fire or controls the fire in the specific area for which
the
system was d@pd. For example. if the design of a sspidder system allows for the simultaneous operation of all sprinklers in a certain room. or over a specific area in a larger space. satisfactory performance wouldmean that the system controUed or ex- tinguished the fire within that room or that area.
The Fire J o u d Performance Tables
define "control" as the prevention of ex- cessive fire spread in accordance with the nature of the occupancy. In certain occupancies. fewer
than
five sprinklm should establish control while in other occupancies more than 100 may be needed. If. by reason of poor dm@ or of Fire Underwriters. human failure. a sprinkler system does Other possible sources were identified, not establish control, its performancebut were not analyzed because of doubts must be labeled unsatisfactory.
as to their reliability. and size of the The Australian definition of satisfac- statistical tory performance is "performance
where. after
the
£ire has been extiu- SATISFACTORY PERFORMANCEguished. the building has suffered only The answer to the question "What minor damage. and the loss of contents constituh satisfactory performance by through fire, water
and
smoke is aan automatic sprinkler system?" is relatively small partion (say of the order i largely subjective. One approach is to of not more
than
20 percent) ofthe
totali
consider that satisfactory performance value involved."Mr. Richardson is a Research Officer in the Codes and Standnrda Group. Division of Building Research. National Research Council. Ottawa. Ontario. Canada.
This paper is a contribution from the Division of Building Research. National- Research
276
Fire
Technology
Satisfactory sprinkler perfonnance is even more difficult to define in terms of life safety. The
Fire
Journal observes that the only reported fatalities in fully sprinklered structures were the result of:Explosions or flash fires,
Ignition of
bedding
or clothing of a person incapable of escaping,Closure of system water supply valves, or
Hazards too severe for effective sprinkler performance.
Australian experience
indicates
that no one has died there in a sprinklered residential building, and only one person has died in an institutional building. The one victim was an elderly woman who dropped a cigarette that ignited therub-
ber chair cushion on which she was sit- ting. Four fatalities, including three in explosions and one in a flash fire, were reported in industrial and commercial occupancies.
Although the New York City statistics do not define satisfactory performance, it appears that satisfactory performance is as assigned by the Fire Patrol of the New York Board of Fire Underwriters.6
The system's capabity to protect the supporting structure of a building must be considered when assessing the system's performance because a struc- tural failure could result in a sprinkler system failwe. If the sprinkler system is to be an alternative to other f i r e resistive measures, it is essential that it be designed to provide the required pre tection.
The type of buildmg construction did not directly affect the performance of automatic sprinklers in the Australian. experience, except in the fourteen cases in which automatic sprinkler perfor- mance was judged to be unsatisfactory. The reason stated is that, in most cases,
only the contents of the buildings were involved in fire. There were very few cases in which the building structure was involved. No damage to, or dietor- tion of. steel roof members was reported in those cases where sprinkler perfor- . rnance was considered satisfactory.
The value of automatic sprinklers in maintaining structural integrity is indi-
cated in fire tests by Factmy Mutual
Research Corp. (FMRCY on unprotected steel library book stacks. (Unprotected structural steel begins to fail a t approxi- mately 1.000"
F.)
The temperature of the steel in stacks protected by sprin- klers did not exceed 500" F. In stacks not so protected, the temperature of the steel was approximately 1,500"F.
In a study to assess the capability of automatic sprinklers to contain fires in exhibition halls following the 1967 Mc- Cormick
Place
Fire in Chicago.' temper- atures of unprotected steel members above the test fire area were recorded to determine possible structural damage. Where sprinklers were permitted to operate normally. the temperatures of unprotected steel. and at the ceiling, w&e in the 500" F range, while tempera- tures ,at the fire source were in the1,700" F range. Where sprinkler dis- charge was purposely delayed, tempera- tures of the unprotected steel ranged from 1,350' F to 1,550" F prior to sprin- kler discharge. Following sprinkler dis- charge, the temperature of the unpm tected steel was reduced to less than
500" F.
These studies show that activated automatic sprinkler systems can protect structural members by keeping temper- atures below the point a t which struc- tural damage will occur.
The NFPA statistics are
based
on fire reports voluntarily submitted to the Association from 1897 to 1969. The statistics probably exclude the manyTechnical Notes
2?7
TABLE 1. Summary of Causes of Unsatisfactory Sprinkler Performunce INFPA)Cause
PREVENTABLE FAILURES Water shutaff
Partial protection Inadequate water supply System frozen
Slow operation
Faulty building construction Obstruction t o distribution Hazard of occupancy Inadequate maintenance Antiquated system
Defective dry-pipe valve (equipment)
Number
of Fires of Total Percent
FAILURES NOT PREVENTABLE
Water shutaff (premature shut-of0 243 0.30
Inadequate water supply (mains broken) 13 0.02
Explosion 184 0.23
External exposure fire 52 0.06
Miscellaneous and unknown 60 0.07
fires which were extinguished by one or two sprinklers and not reported. Includ- ing these unreported fires would increase the reported satisfactory performance percentage. According to these statis- tics, sprinkler operation was judged to be satisfactory in 96.15 percent of the 81.425 fires reported. The causes of un- satisfactory performance are summa- rized in Table 1.
The Australian statistics include vir- tttally all fires involving sprinkler opera- tion in Australia and New Zealand from 1886 to 1968. In both countries. alarms from fires involving sprinklers are transmitted to the fire brigade and the resulting fire statistics are reported na- tionally. These statistics include data from small and large fires and appear to give a more complete representation of sprinkler response to all types of fires than the NFPA statistics. They should be evaluated, however, in terms of Australian building and maintenance practices, which may differ from North American practices.
Sprinkler operation was judged to be satisfactory in 99.75 percent of the 5.734
fires analyzed in the Australian statis- tics. Possible reasons for this slightly higher level of satisfactory performance are:
By law, automatic sprinkler systems are subjected to weekly maintenance procedures.
Most have electrical supervision of trouble signals and water flow alarms with automatic transmittal to the fire brigade.
Causes of unsatisfactory performance are summarized in Table 2.
Australian statistics show that 12.6 percent of the sprinklered buildings were of fireresistive construction and 84.3 percent were not. (Information on
the remaining 3.1 percent was not
reported.) More than half (58.1 percent) of the buildings were multistory. 38.8 percent were onestory, and the rest of unknown height.
These
data suggest that construction type and height of building do not play a sigmfkant role in sprinkler system reliability.Australian statisticsa based on fires from 1968 to 1973 indicate that sprin- kler operation was judged to be satisfac-
278
F i eTechnology
TABLE 2. Summary o f Causes of Unsatisfactory Sprinkler Performance (Austmlian)Number Percent
Cause o f Fires o f Total
PREVENTABLE FAILURES
Partial protection 4 0.07
High hazard 1 0.02
Inadequate water supply 1 0.02
FAILURES NOT PREVENTABLE
External exposure 4 0.07
Explosion 3 0.05
Others 1 0.02
tory in 99.36 percent of the fires. These data show that modem building prac- tices and procedures have not signifi- cantly affected the level of satisfactory performance.
New York City statistics are based on fires responded to by the New York Board of Fire Underwriters between
1969 and 1978. Representatives of the Board respond to almost all fires in sprinklered buildings. Details of the few fires to which they did not respond were obtained from the fire department.
The New York City statistics ,are reported under three headings: high-rise office buildings, other high-rise buildings, and buildings that are not high-rise. A total of 5,709 fires involving
sprinklers are included and satisfactory performance is reported in 96.5 percent
of them. The causes of unsatisfactory performance are summarized in Table 3.
IMPROVING SPRINKLER SYSTEM RELIAB~LITV
Many of the causes of unsatisfactory performance of sprinkler systems are preventable. If a system designed, in- stalled, and tested to current standards and modern equipment as specified in those standards is used, many of the causes of failure shown in Tables 1, 2 and 3 can be avoided.
When only the factors that commonly available equipment and procedures can reasonably be expected to handle are considered, the reliability of sprinkler systems can theoretically be increased above those reported. For the NFPA statistics, the increase is from 96.15 per- cent to 99.32 percent; for the Australian statistics, from 99.75 percent to 99.86 percent; and for the New York City statistics. from 96.57 percent to 98.97 percent.
TABLE 3. Summary of Causes of Unsatisfactory Sprinkler Performance (New York Cityl
-- . - - - -- -
Number Percent
Cause of Fires of Total
PREVENTABLE FAILURES
Water shut-off 111 1.94
Obstruction to distribution 1 0.02
Partial protection 12 0.21
Inadequate water supply 3 0.05
Faulty building construction 10 0.18 FAILURES NOT PREVENTABLE
Arson
S stem not restored following fire X s h fire, high haz+rd and explosion External exposure fire
Technical Notes
279
The analysis of the causes of sprinkler system failures indicates several solu- tions to reduce failures and improve the reliability of sprinkler systems:
The sprinkler system should be d e signed. installed, and tested in confor- mance with NFPA 13. "Installation of Sprinkler Systems." This design stan- dard incorporates modern installation techniques and equipment and is r e garded as the stateof-theart.
The sprinkler system should be com- plete throughout the building being p r e
tected. This means having sprinklers in- stalled in
all
areas, including concealed spaces containing combustibles and under obstructions. as required by NFPA 13.Where an occupancy presents an unusual hazard that is not directly ad- dressed in NFPA 13, the appropriate sprinkler system requirements in other NFPA standards must be used to s u p plement the general rules in NFPA 13.
The sprinkler system valves and water supply should be electrically supervised and waterflow and trouble signals should be automatically trans- mitted to a location where appropriate action will be taken.
The sprinkler system, including supervisory equipment, should be main-
tained and tested in conformance with present-day fire protection standards.
The building in which the sprinkler system is installed should be con- structed or renovated in conformance with modern building codes for proper fire compartmentation and firestopping. In new buildings,
all
of these solutions can be accomplished with relative ease. In existing buildings, some of the solu- tions may be difficult and costly. However, measures such as valve and water supply supervision and proper maintenance can be provided without difficulty in existing buildings and will give high returns, since they tend to pre- vent the most common causes of sprin- kler system failure.R E F E R E N C E S
'
Barria. James P.. and CoateRussian ISario L.. "Sprinkler Trade-offs, Are TheyJustified," Fire Journal, VoC 74. No. 3 [May
19801. p 63 70.
: ~ei!$: ~ d w a r d J.. and Flemin Russell
P..
"w&
Sprinkler Trade-offs ~ o r t . " BuiLd- ing Standards, VoL 1, No. 1. Inkwtional Conference of Building Officials (January-February 1981).
'
Colville. James: Wala h. Daniel, and Van-noy. Donald W.. "A Study of Fire Losses in hw-Rise Multi-Family Residential Build-
ings," University of M land, Department of Civtl ~ n ~ n e e r i n g . y o ~ e ~ Park, MD
(19791.
'
U:S. De. artment of Energy, "AutomaticSprinkler berfnmanre and Reliability in
United States Department nf En- Facil.
ities, 1952-1980, " Washington, DC (19821.
Powerg. Robert W., "Sprinkler Ex*
ence in High-Rise Buildin@ (1969-19791,''
SFPE Techiaolagy Report 7 9 1 . Soc~ety of
Fire Protection Engineers, Boston 119791.
'Cotton, P.E., "Fire Tests of Library Baokstacks.'~ NFPA Quarteri Nat~onal
Fire Protection Association. &incy, MA.
Vol. 84. NO. 15 ( A riI 1960l. pp. 281-295.
'
Webb, W . A . "kffectlveness of S rinlderSystems in Exhibition Halls,'. Pire fpchnol-
o ~ y , Vol. 4. No. 2 lMay 19681. pp. 115-125.
"
Ma att. H.W.. "The Australian Ex ri mce w% A"tomatic Sprinklers." Fire8;
nol, Austrahn Fire Protect~on Aaaociation.
T h i s paper, w h i l e b e i n g d i s t r i b u t e d i n r e p r i n t form by t h e D i v i s i o n of B u i l d i n g R e s e a r c h , remains t h e c o p y r i g h t of t h e o r i g i n a l p u b l i s h e r . It s h o u l d n o t be reproduced i n whole o r i n p a r t w i t h o u t t h e p e r m i s s i o n of t h e p u b l i s h e r . A l i s t of a l l p u b l i c a t i o n s a v a i l a b l e from t h e D i v i s i o n may be o b t a i n e d by w r i t i n g t o t h e P u b l i c a t i o n s S e c t i o n , D i v i s i o n of B u i l d i n g R e s e a r c h , N a t i o n a l R e s e a r c h C o u n c i l of C a n a d a , O t t a w a , O n t a r i o , KIA 0R6.
