UNIT II STUDY GUIDE
Fire Protection, Detection, and
Suppression Systems
Course Learning Outcomes for Unit II
Upon completion of this unit, students should be able to:
3. Explain how the properties of fire influence design and installation criteria.
3.1 Summarize the benefits of fire protection systems in different types of structures.
3.2 Describe the stages of fire from the ignition phase through decay.
5. Examine emerging technologies related to fire protection.
5.1 Differentiate between the types of fire protection systems.
6. Evaluate design specifications for fire alarm systems.
6.1 Describe the advantages that fire protection, detection, and suppression systems have on life
safety and loss prevention.
Required Unit Resources
Chapter 1: Overview of Fire Protection, Detection, and Suppression Systems
In order to access the following resource, click the link below.
Wilmot, J. (2016, December). Shattering myths: Mass media’s inaccurate portrayal of fire-sprinkler systems
needs to be rectified. PM Engineer, 22(12), 8–9.
https://libraryresources.columbiasouthern.edu/login?url=http://search.ebscohost.com/login.aspx?direc
t=true&db=bth&AN=120179610&site=ehost-live&scope=site
Unit Lesson
Most people believe if you hold a lit match, cigarette lighter, or burning paper under a sprinkler head, it will
activate every sprinkler head in the room, or if you pull the fire alarm, the entire sprinkler system will activate.
These myths or even misrepresentations have been seen in many movies and TV shows making their way
into the mainstream media for their dramatic effects. Some of the films that show these misrepresentations
are Hocus Pocus, where multiple sprinkler heads are activated by holding a lighter against a single head, and
Changing Lanes, where Ben Affleck activates the entire system by holding a burning piece of paper under the
fusible link of a sprinkler head (Johnson, 2017).
Why have these misrepresentations become so real for many? Is it easier to believe what we see than to factcheck it? Some say, “it is just a movie!” However, these misrepresentations are engrained into the behavior of
many during emergency conditions. Fire prevention’s goals are to educate the public and modify behavior.
Modifying behavior can be changed through education and by targeting specific audiences. So how does one
educate or change behavior regarding fire protection, detection, and suppression systems? What activates
sprinkler systems or even a sprinkler head?
It takes heat in the form of fire to activate one sprinkler head by melting the fusible link. Fire is a chemical
reaction that requires three elements: heat, fuel, and oxygen. These elements are essential for combustion to
occur. Historically, this concept is referred to as the fire triangle and is illustrated as a triangle. In order to
eliminate fire, the separation or removal of one of the elements of fuel or oxygen and then the reduction of
heat are required. Today, the concept is referred to as the fire tetrahedron, adding another side illustrated as
a pyramid. The fourth side is the uninhibited chain reaction. Fire prevention requires the separation,
segregation, or removal of one of these elements in order to mitigate the possibility of a fire. The goal is to
reduce or remove ordinary combustibles and flammable liquids that contribute to the spread of fire or even
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support combustion. However, if these combustible items are not separated, itUNIT
can lead
to a fire
that is
x STUDY
GUIDE
classified as either unsuppressed or suppressed. Unsuppressed fires leave a Title
fire signature that is detectable
to fire protection detection systems. The fire signature is the byproducts of combustion (smoke, heat, carbon
monoxide, light, and other byproducts). What is unsuppressed fire? Gagnon (2008) concluded that
unsuppressed fires consist of three stages, which are shown in the graphic below.
Each of these stages of fire can be detected by a proper fire alarm control unit (FACU). Suppressed fire is
when a suppression agent is applied, extinguishing the fire. As soon as the agent is applied, the fire begins to
decay. However, multiple factors influence the effectiveness of suppression agents to include wind, oxygen
levels, and temperature, as well as the method of application. Proper application of a fire protection system
will shorten fire growth and the developmental stages of fire (Gagnon, 2008). There are several illustrations in
fire behavior textbooks that show the development of fire from the incipient stage through the decay stage.
The illustration resembles a traditional bell curve showing the ignition of the fire through the growth period and
then the decay of fire. During all phases, heat is present, and oxygen levels dictate the speed of growth. With
today’s new construction, fire reaches the peak of fire growth sooner than previous models indicated. In
addition, building construction type and factors of ventilation affect the development of fire and the shape of
the curve on the model.
Points to Ponder Scenario
Firefighters respond to a warehouse and distribution facility storing coffee, food commodities, household
chemicals, and cleaning products that are piled in high-rack storage. Originally, the structure stored materials
that were classified as noncombustible, and the fire suppression system was designed for noncombustible
materials with in-rack sprinkler heads. Over time, the warehouse included combustible materials.
The rigid steel frame construction is reinforced with concrete slab floors. The walls are heavy corrugated
metal on the upper part with masonry nonbearing on the bottom. The roof decking is corrugated metal panels
approximately 1/8-inch thick, 6-feet wide, and 20-feet long laid on top of the rigid steel frames. Offices are
located on the southeast end (Side B) of the structure. The warehouse was renovated in 2015, adding 10,000
square feet of floor space to the north end (Side D). On Side A near Side D (Quadrant 4) are rectangular
unprotected openings used for offloading products at the loading docks. The automatic sprinkler system, fire
pump (due to low pressure with the water distribution system), and a monitored fire protection system were
upgraded.
Power to the structure was out for several days due to flooding in the area, causing the loss of the
underground primary power supply. Workers were using handheld lights and portable generators to provide
light. Because of the poor lighting conditions, a forklift operator ran into the main support of the structure,
causing severe damage and requiring arc welders to be on site to repair the damage. Several of the
warehouse workers reported sparks dropping from the welding that ignited nearby cardboard boxes. They
also reported that the heads in front of the loading dock doors were barely operating, and there were no
audible alarms sounding as the fire started. As firefighters entered the structure, they had to wade through
large amounts of product debris that was falling from the high-rack storage, and smaller debris was floating
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out the loading dock doors. The products piled in the high racks hindered the operation
of the GUIDE
in-rack sprinkler
UNIT x STUDY
heads, allowing the products on the lower shelves to continue burning.
Title
Debris inside warehouse
Regarding the Points to Ponder Scenario, consider the following questions. Was the suppression system
adequate for the high-rack storage? Did the high-rack storage hinder the FACU from detecting the smoke and
heat? Were the in-rack sprinkler heads the best option for the high-rack storage? Even though National Fire
Protection Association (NFPA) 13 governs the minimum distance between sprinkler heads and storage, was
that the real problem in the scenario? Was the problem the detection system? Why was there no audible
alarm?
Fire detection system
There are passive and active forms of protection. Passive refers to the building design and construction type.
Active refers to the protection system. There are two types of protection systems that are considered active:
fire detection and fire suppression. In the scenario, neither protection system functioned properly. Fire
detection systems require detectors to be placed in areas that can detect fire byproducts and the dynamics of
the fire. This involves the type of ceilings, location of the detectors on the ceiling, and the surface of the
ceiling. NFPA 72 provides the standards and minimum requirements for the placement of the detectors. Each
of the following detectors—heat, smoke, beam, and gas—has specific requirements based on these
standards. Based on the scenario, do you think that a ceiling-mounted detector would have been effective
with the burning boxes on the floor? The placement of detection systems are calculated based on the fire
growth potential and room characteristics with the segregation and separation of combustible materials. This
also takes into account airflow that affects the dynamics of fire.
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UNIT x STUDY GUIDE
Title
Sprinkler head
Sprinkler head
In the scenario, it was reported that the sprinkler heads were barely operating. Historically, sprinkler systems
have protected structures and their contents and extinguish a fire with one or two heads activated. Why were
the sprinklers barely operating in the scenario? Some reasons could be poor maintenance, system shut
down, low water pressure, or damaged heads or components.
Could prevention have eliminated the fire? Would educating workers about the hazards of discarded
cardboard boxes around the high-rack storage prevented the fire? Did poor housekeeping contribute to the
fire? Prevention is about modifying behavior though education. In addition, prevention is segregating and
separating the elements of heat, fuel, and oxygen. Another effective means is inspection. Inspections identify
vulnerable areas and mitigate potential fire sources, such as the housekeeping practices and improperly
stored combustible materials. In addition, periodic inspections examine FACUs, the condition of fire protection
systems, and the operational readiness and maintenance of the system (Brakhage et al., 2016).
Conclusion
Fire protection, detection, and suppression systems are critical to life safety, protection, and prevention of fire.
Understanding fire behavior and the products of combustion is critical in order to design protection, detection,
and suppression systems. There are various fire protection detection systems or alarm systems from
automatic to manual. These systems are designed to activate due to smoke, heat, and light to alert occupants
and notify the fire department. Sprinklers are activated based on fire conditions, and only one or two heads
normally operate and suppress the fire. However, there are times, like in the scenario, that multiple sprinkler
heads are activated due to fire growth and the inability of the sprinklers to discharge water on the fire. This
could be the result of the high-rack storage with the combustible items on the bottom burning and the
combustible items on the top shielding the fire like an umbrella.
References
Brakhage, C., Abrams, A., & Fortney, J. (Eds.). (2016). Fire protection, detection, and suppression systems
(5th ed.). Fire Protection Publications.
Gagnon, R. M. (2008). Design of special hazard and fire alarm systems (2nd ed.). Delmar Learning.
Johnson, C. (2017, May/June). Hollywood thinks they all go off at once! Fire sprinkler misrepresentations
in the media. Sprinkler Age, 36(3), 18–19. https://sprinklerage.com/hollywood-thinks-go-off/
Suggested Unit Resources
In order to access the following resource, click the link below.
You are encouraged to read this article about how understanding fire dynamics can provide designers with
the means to comprehend how a fire will grow and spread within a structure and how best to control that
growth, including the fire triangle and how it applies to the fireground.
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Madrzykowski, D. (2016). Fire dynamics: The science of fire fighting. International
ServiceGUIDE
Journal of
UNITFire
x STUDY
Leadership & Management, 10, 27–35.
Title
https://libraryresources.columbiasouthern.edu/login?url=http://search.ebscohost.com/login.aspx?direc
t=true&db=a9h&AN=119098127&site=ehost-live&scope=site
Learning Activities (Nongraded)
Nongraded Learning Activities are provided to aid students in their course of study. You do not have to submit
them. If you have questions, contact your instructor for further guidance and information.
Reflect on the concepts you have learned during your readings. What do you understand completely? What
did not quite make sense? The purpose of this assignment is to provide you with the opportunity to reflect on
the material you have read and to expand on it. If you are unclear about a concept, either review it in the
textbook or ask your professor. Can you apply what you have learned to your career? How?
This is not a summary. A reflection paper is an opportunity for you to express your thoughts about the
material you are studying by writing about it. Reflection writing is a great way to study because it gives you a
chance to process what you have learned and increases your ability to remember it.
Use these guidelines as you reflect on the course material.
•
•
•
What are your thoughts about the main topics of the fire triangle verses tetrahedron?
Why are fire dynamics important to fire protection?
Explain the dynamics of a smoldering chair fire in a closed room. How does the fire triangle apply to
the fire?
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