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nit I IntroductionConcepts Associated with the Dynamics of FireBe sure to pay attention to concepts in the study guide. There are also great graphics to complement the study guide. Below, is a great one!JournalBe sure to include a title page with your name on it.Be sure to format your discussion in paragraphs.InstructionsIn the introduction to the unit lesson, it is mentioned how previous courses may not have prepared you well enough to undertake the principles of fire behavior and combustion. Do you agree? If not, what might you need to do to be fully prepared?Please do not use any outside material to support your rationalization or even disagreement of this concept. If you disagree with this statement, express why, supporting your disagreement with tangible thoughts.Your journal entry must be at least 200 words. No references or citations are necessary.



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Concepts Associated with
the Dynamics of Fire
Course Learning Outcomes for Unit I
Upon completion of this unit, students should be able to:
2. Categorize the components of fire.
2.1 Distinguish measurement in understanding fire behavior.
5. Define the concepts associated with the chemistry of fire.
5.1 Recognize the chemical elements that are related to fires.
6. Discuss various materials considered fuel for fires.
6.1 Describe the change among the states of matter and the changes in enthalpy associated with
Learning Outcomes
Learning Activity
Unit Lesson
Chapter 1
Unit I Essay
Unit Lesson
Chapter 3
Unit I Essay
Unit Lesson
Chapter 1
Unit I Essay
Reading Assignment
Chapter 1: Fire Measurement and the SI System of Units
Chapter 3: Physical and Chemical Change, pp. 39–41
Unit Lesson
Concepts Associated with the Dynamics of Fire
What is fire behavior and combustion? Many of us believe we know the answer either from life experiences
on the fire ground or from classes taken in the fire academy. However, do we really know? What are the
characteristics of fire and its behavior or combustion? Is there an art to reading fire? Is fire behavior its own
language? Senior fire officials may have taught us the fire triangle or even the tetrahedron. Do you really
understand it? Is fire as simple as removing one of the elements and it goes out, or is there more? Is there a
need to understand the differences between mass and weight that involves heat, energy, and smoke? Do you
really need to know the importance of measurement in understanding fire behavior? Do we really need to
understand enthalpy in relation to heat or smoke? Do we need to understand buoyant smoke and any
incomplete combustion involving a fire? Why are these concepts important in understanding fire? Has the
need to understand fire behavior gone unheeded? Are you prepared and equipped to undertake the principles
of fire behavior and combustion?
According to ancient Greek mythology, fire was stolen from the gods and given to humankind by Prometheus
(Morris, 2017). In Greek mythology, since fire was introduced, it has been used for good and evil over the
centuries. When controlled, fire provides heat, energy, and light. Out of control fire is devastating and has
FIR 3301, Fire Behavior and Combustion
caused many injuries and
deaths. Gorbett and Pharr
(2011) have reviewed the
devastation of fire throughout
the centuries, describing fire is
a serial killer that continues
today. Fire-related injuries and
even deaths have been
contributed to the behavior and
attitude of firefighters (National
Fallen Firefighter Foundation,
2013). They further suggested
one of the causes is the lack of
preparedness. Gorbett and
Pharr (2011) suggest these
injuries and deaths many times
are due to firefighters not
understanding fire behavior.
Building on the Scenario
A caller reported a fire at a Garden Apartment. Engines 2 and
5, Tower 2, Rescue 2, and Battalion 1 were dispatched for a
possible structure fire involving an apartment building. While
reporting the morning traffic, the local news channel observed
a column of smoke coming from the direction of the apartment
and notified dispatch. Upon Engine 2’s arrival, he reported
heavy smoke from Side “A.” Engine 5 was ordered to lay a
supply line into Engine 2. Engine 2’s officer and one firefighter
went to the front door, entering the foyer area, and advanced
up the stairs and down the hallway.
As they opened the door, they immediately observed thick
black smoke pulsing and banking down to the floor under
pressure. As they advanced the handline into the apartment,
they noticed the kitchen cabinets were well involved, and they
could make out the stove with a saucepan on it. Within
seconds after reaching the kitchen, the temperature in the
room increased, burning their faces where their Nomex hoods
were not donned properly.
Are you prepared as a
firefighter? Are injuries or even
deaths the result of poor
decisions on the fire ground due
to not completely understanding
When opening the nozzle, there was a loss of pressure in their
fire behavior and combustion?
handlines. As a result, the fire appeared to double in size
We all know fire is the rapid
within a few minutes. At the same time, Tower 2’s engineer
oxidation of a combustible
described thick black smoke pushing into the atmosphere from
material releasing heat, light,
the second-floor window. The apartment’s dimensions are
and various reaction products in
32’4” x 20’6” x 8’.
the exothermic process of
combustion (Gorbett & Pharr,
2011). In addition, we understand the components of combustion, using oxygen, fuel, and heat to explain the
ignition, growth, and then decay of the fire. Using the fire tetrahedron, we can describe how combustible
material near the fire off-gasses and the area around the combustible material must be cooled to stop the
fires progression and the superheated air-track. According to Gann and Friedman (2015), understanding fire
behavior and combustion causes one to realize that measurement is another key component to
understanding the fire phenomena. The authors note that firefighters need to know when the fire started, how
rapidly it grew, how hot it became, and how severe the threat to the population. They continue by suggesting
firefighters need to quantify this information to understand fire.
In the fire service, we understand that the terms “fast moving” or “big” in relationship to smoke and fire have
different meanings to each of us. Many times, our definitions are based on experience, and the definitions
change throughout our career. What was once a big fire, may be moderate today. According to Gann and
Friedman (2015), in order to quantify fire behavior, we need to understand measurement in terms of SI units
from the French term, Système International d’ Unités). Gorbett and Pharr (2011) define SI units as a “system
for quantifying measurement that uses meters, liters, grams, and calories” (p. 19). How can one compare
measurement to fighting fire? Is it essential in firefighting? Are we really going to perform calculations on the
fire ground to understand the phenomena of fire? Gann and Friedman (2015) suggest the basic
measurements for fire phenomena to occur is time, length, area, volume, mass, density, force, pressure,
enthalpy and energy, power, and temperature. How do you apply each of these? In the scenario below, how
would you use measurement to help understand the fire phenomena?
Points to Ponder
In the scenario in the right sidebar, did the fire generate energy? Did the energy increase within the fire room?
Was there transfer of heat from one object to another? Was there an increase in pressure within the volume
of the room? Was there an increase of temperature noted? Was there an increase in the spread of fire
outside the room of origin?
FIR 3301, Fire Behavior and Combustion
Reaction of Enthalpy
In the scenario, the cooking oil in the saucepan reached autoignition, creating a fire that continued until the
room was totally involved. As the cooking oil was heated, a chemical reaction occurred (Figure 1 [Bonds “A-B”
Molecule representing the cooking oil]) breaking bonds and vaporizing into a gas (Figure 2 [“A” “B” Molecular
Fragments representing the volatile gas]). At this point, a change occurred, and heat is being released and
absorbed by other solids, under a constant pressure, with a temperature rise around the reaction. As the
vapors or gas ignites, combustion occurs (Figure 3). Energy is continually being released and absorbed under
pressure (Figure 4) creating soot, a solid particle in the smoke, and collecting on the ceiling and walls. The
process starts over as the soot is heated and thermal degradation (pyrolysis) occurs under pressure, creating
a volatile gas (reacting with air) in the smoke that ignites (Figure 5) resulting in flashover, roll over, or
backdraft. This continues creating a full-scale heat release (Figure 6). The absorption or the release of energy
under pressure is known as enthalpy. During the enthalpy process the release of heat feeds back to the solids
around the fire. This feedback is a loop that continues under pressure, either positive or negative. Figure 7
below shows the method of heat being released or absorbed though the enthalpy process.
Figure 1
Figure 2
Figure 3
Figure 5
Figure 6
Figure 4
Figure 7: Enthalpy
FIR 3301, Fire Behavior and Combustion
Factors such as the nature of the material can influence the heat transfer in enthalpy.
on the
nature of the exposed surface, the higher bond enthalpy requires more energyTitle
(heat) to break the bond. This
also depends on the distance between the heat source and the exposed surfaces.
Exothermic and Endothermic Reaction
If the reaction of enthalpy is positive, it is considered endothermic,
and if it is negative, it is considered exothermic (Figure 8). The
following is an example of this: a rag is used to coat an axe handle
with linseed oil. You place the rag on the table and as the rag begins
to dry, oxidation takes place, producing heat resulting in fire. The
combustion of the rag is an exothermic reaction because you feel the
heat from the fire. Exothermic reaction is the only phase in which you
feel the heat when fighting fire.
Figure 9 shows the rate of heat transfer of cooking oil as a liquid
undergoing the combustion phase across the surface indicated. The
flame above the saucepan is fed by the thermal degradation of the
liquid cooking oil generated across the given surface of the
Diffusion flame is the rate of supply of vapors (as seen coming from
the sauce pan) coupled to their rate of burning; at the same time,
heat is being transferred from the flame to any surface around the
fire (Drydale, 1985). This process is continually releasing energy
necessary to produce the vapors to support combustion. As heat
increases, the speed of the polymeric molecules increases as the
cooking oil splits into smaller fragments, which can vaporize and
escape from the surface of the sauce pan. This process is essential
to maintain the flow of vapors and support the diffusion flame
(Drydale, 1985).
Figure 8
Thermal Degradation
Rate of
Figure 9
FIR 3301, Fire Behavior and Combustion
Lack of preparedness was cited in firefighter injuries and fatalities. Some of the reasons for the injuries and
fatalities were the attitudes and behavior firefighters have about the chemistry and physics of fire.
Understanding fire and how heat transfers, increasing flame spread from one object to another object, is the
key to understanding fire behavior and fire processes. One of the main constituents in fire growth is learning
the rate at which fire will spread over adjacent combustible materials is affected by mass, energy, heat, and
enthalpy. It is hoped that understanding thermal degradation (pyrolysis) and gas phase of combustion will
drive you to develop a more practical approach to understanding the principles of fire behavior and
Drydale, D. (1985). An introduction to fire dynamics. Somerset, NJ: Wiley.
Gann, R. G., & Friedman, R. (2015). Principles of fire behavior and combustion (4th ed.). Burlington, MA:
Jones & Bartlett.
Gorbett, G. E., & Pharr, J. L. (2011). Fire dynamics. Upper Saddle River, NJ: Pearson.
Morris, L. (2017). Origins of fire according to the Greeks. Retrieved from
National Fallen Firefighter Foundation. (2013). Everyone Goes Home—The 6 root causes of firefighter line-ofduty-deaths. Retrieved from
Suggested Reading
In order to access the following resources, click the links below.
You are encouraged to watch at least the first 8 minutes of the 40-minute presentation by Steve Kerber and
Dan Madrzykowski that gives a good overview of the related issues of science and firefighting. It was filmed at
the International Association of Fire Fighters (IAFF) Redmond Symposium in August 2013.
IAFF. (2013, August 23). Fire behavior and tactical considerations [Video file]. Retrieved from

Click here to access the transcript for this video.
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.
For this activity, you are asked to prepare a reflection paper. 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.
FIR 3301, Fire Behavior and Combustion
Use this image along with the questions to guide you in reflecting on the course material.

What are your thoughts about the main topic of heat absorption and the release of heat under
Why is fire behavior and combustion important to firefighting?
Explain the dynamics of a smoldering chair fire in a closed room that increases in size. How does the
heat absorption or release apply to the fire?
FIR 3301, Fire Behavior and Combustion

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