Frequently Asked Questions
effective are fire sprinklers?
Sprinklers operate automatically in the area of fire origin, preventing a fire from
growing undetected to a dangerous size, while simultaneously sounding an alarm.
Automatic fire sprinklers keep fires
small. The majority of fires in sprinklered buildings are handled by one or two sprinklers.
How do fire sprinklers
Automatic fire sprinklers are individually heat-activated, and tied into a network of piping with water
under pressure. When the heat of a fire raises the sprinkler temperature to its operating point (usually 165ºF), a solder
link will melt or a liquid-filled glass bulb will shatter to open that single sprinkler, releasing water directly over the
source of the heat.
When a fire starts, do all sprinklers discharge at once?
Contrary to what is sometimes
shown on television sitcoms, all sprinklers in the building do not operate simultaneously. Sprinklers distribute water directly
where it is needed to confine and control a fire. In the majority of fires, only one or two sprinklers are required to operate.
sprinklers discharge accidentally
The likelihood of a sprinkler discharging water in the absence of a fire is very
small. Each model of sprinkler is subjected to rigorous laboratory tests to guarantee long-term integrity, and every single
sprinkler is hydrostatically tested at twice the maximum system water pressure prior to leaving the factory.
of Factory Mutual Research indicate that the probability of a standard response spray sprinkler discharging accidentally due
to a manufacturing defect is only 1 in 16,000,000 sprinklers per year in service.
How reliable are fire sprinklers?
All fire protection features have a reliability factor. Walls and shafts can be breached by means of poke-throughs
and building alterations. Exit doors can be blocked or locked.
Sprinklers may be the most reliable fire protection
system known. Detailed fire records for Australia and New Zealand (where fire must be reported) for the years 1886 through
1968 showed that 99.76% of all fires were extinguished or controlled by the sprinklers. Fire records in this country are less
dependable due to lack of full reporting, especially for small fires where the sprinklers are successful. Nevertheless, the
range includes a 96.2% success record reported by the National Fire Protection Association for the years 1925 through 1969,
98.4% success record for New York City high-rise buildings between 1969 and 1978, and a 98.2% success record for U.S. Department
of Energy facilities between 1952 and 1980.
How much water damage is caused by sprinklers?
sprinklers attack the fire while it is still small, the total amount of water needed for fire suppression is small, often
less than 50 gallons per minute. If the fire is permitted to grow, the fire department will typically apply hundreds of gallons
of water per minute during their operations. For this reason, total amounts of water used in sprinklered buildings approximate
one-tenth the amounts used in fires in non-sprinklered buildings.
What is the life safety record for fully sprinklered
Aside from fire fighting and explosion fatalities, there has never been a multiple loss of life in a fully
sprinklered building due to fire or smoke. Individual lives have been lost when the victim or his clothing or immediate surroundings
became the source of the fire.
A National Fire Protection Association study for the years 1971-1975 found that approximately
20 lives are lost each year in this country in sprinklered buildings, as compared to approximately 4,000 per year in unsprinklered
buildings. Some 68% of the lives lost in sprinklered buildings were due to explosions, and an additional 18% were due to the
fact that the fire originated in an unsprinklered area of the building.
What is a "listed" sprinkler?
sprinklers installed in conformance with National Fire Protection Association (NFPA) standards must be listed. A listing basically
means that the manufacturer has successfully submitted the product to an independent laboratory for testing against an established
standard of quality. Both Underwriters Laboratories and Factory Mutual Research have established special listing categories
for fire sprinklers.
What is a residential sprinkler?
The residential sprinkler was the first sprinkler
to incorporate the new fast response technology. It was developed in the late 1970s in conjunction with federally funded research
into a low-cost residential sprinkler system. Research showed that in order to make relatively small domestic water supplies
effective for sprinkler protection, and to control a residential fire before small rooms could fill up with toxic smoke, a
sprinkler needed to be considerably more sensitive to heat than the standard sprinklers. The needed residential sprinklers
were developed by sprinkler manufacturers while appropriate product testing criteria were being developed by Underwriters
Laboratories and appropriate installation rules were being developed by the NFPA Committee on Automatic Sprinklers. The result
is that there are now listed residential sprinklers which can be installed in conformance with NFPA 13D and, in some cases,
NFPA 13. The listed residential sprinklers are tested not only for fast response, but also for special distribution and cooling
What is a quick response sprinkler?
Quick response sprinklers are those which are tested under
the same product testing criteria as standard sprinklers, but also exhibit the fast response characteristics of listed residential
sprinklers. Some manufacturers developed these sprinklers by inserting the residential sprinkler operating mechanism into
a standard sprinkler frame. Other manufacturers successfully submitted residential sprinklers to the laboratory for testing
under the criteria for standard sprinklers. In both cases, Underwriters Laboratories designated these special sprinklers as
quick response sprinklers. By establishing a separate listing category, UL has identified listed quick response sprinklers
as being different from both standard and residential sprinklers. Unlike the residential sprinklers, quick response sprinklers
are not required to have special cooling and distribution abilities.
What are "trade-offs" between fire protection
system costs and savings?
The system cost can often be offset by insurance savings, and by specific design alternatives
or "trade-offs" permitted by most building codes in view of the superior protection afforded by sprinklers. These trade-offs
often include reduced fire-resistant requirements for structural components, longer exit travel distances, and larger building
areas and heights.
How often should my system be inspected?
The National Fire Protection Association publishes
NFPA 25 Inspection, Testing and Maintenance of Water-Based Fire Protection Systems. This document recommends that control
valves without electronic supervision be checked on a weekly basis, just to make sure that they are in the open position.
Other system components have different requirements. Check with the NFPA 25 or the manufacturers' literature for details.
least four times each year, a full sprinkler system inspection should be performed by a knowledgeable professional. Some states
and cities require more frequent inspections. Most sprinkler contractors offer economical long-term service agreements. These
contractors can provide you with the test certificates which will comply with your insurance company and local fire department
inspection requirements. To learn more about inspection, please visit the Modern Sprinkler website...
inspection affect my insurance rate?
Buildings which are completely sprinklered enjoy special reduced rates. However,
if the insurance company does not receive verification of system inspection, penalties in the form of higher insurance rates
The Insurance Services Office (ISO) publishes a Commercial Fire Rating Schedule (CFRS). Section 402 of the CFRS
requires building owners to have annual inspections of sprinkler systems to enjoy the "sprinklered" insurance rate.
an inspection is overdue for up to 12 months, a 5% penalty applies. If the inspection is overdue for 12-24 months a 20% penalty
applies. If an inspection is 24-36 months overdue, a 60% penalty applies. If after 36 months an inspection is still not performed,
a fully sprinklered building is rated as "Unsprinklered" for the purpose of insurance, with no credit allowed.
with your insurance carrier about the rate for your building. Even though it is fully sprinklered you may not be getting as
big a discount you're entitled to. Get your sprinkler system inspected and take full financial advantage of your fire sprinkler
system. To learn more about inspection, please visit the Modern Sprinkler website...
How does inspection affect
Recent court decisions have held building owners and managers liable because they did not have a fire
sprinkler system in a building which had a fire. Even though sprinkler systems were not required in these buildings by fire
or building codes, owners still had to pay out millions of dollars. Similarly, an owner or manager of a building with a fire
sprinkler system would be held liable if he failed to maintain that system in a working condition.
In addition, owners
and managers of commercial and business facilities have an obligation to maintain safe conditions for employees and occupants.
By working in a sprinklered building, employees come to expect a certain level of protection. It is incumbent on the owner
to maintain this level of protection. To learn more about inspection, please visit the Modern Sprinkler website...
National Fire Sprinkler Association
For more FAQs on fire sprinklers and their applications, visit the National Fire Sprinkler