1. Unit 1 Introduction to Fire Safety
1.1 Importance of Fire Protection
How could a fire effect an organization?
NOTE: 40% of businesses hit by fire never reopen!!

2. 1. Introduction 1.2 The Overall Fire Picture – NFPA 2009
Every 22 seconds a fire department responds to a fire
1,451,500 fires reported in the US
3,320 deaths, 84% of which occur in residential homes
16,705 civilian injuries occurred as a result of fires
$15.4 billion in direct losses

3. Introduction 1.3 Where Fires Occur 49% were outside fires
34% were structural fires (78.2% residential)
17% were vehicle fires

4. 1. Introduction 1.4 Causes of Residential Fires and Fire Deaths
Cooking
Heating
Arson

5. 1. Introduction 1.5. NFPA Strategies Residential properties
Public Fire Safety Education
Smoke Detectors and Escape Plan
Residential Sprinkler Systems
Fire safe home products
Special fire safety needs for high risk groups
Industrial properties

6. 2. Chemistry & Physics of Fire
2.1 Nature of Heat
Heat – A quantity of thermal energy
- symbol is Q
Units of Heat: BTU or Calorie
Formula for heat: Q = MC∆T

7. 2. Chemistry & Physics of Fire
2.2 Specific Heat – The amount of heat required to raise one pound of a substance by 1ºF
Units will be BTU/lb. ºF

8. 2.Chemistry & Physics of Fire
2.3. Sensible Heat Change – the change in heat content of a material due to a temperature change only, no phase change.
2.4. Latent Heat Change – the change in heat content of a substance when it undergoes a phase change only, no temperature change.
2.5 Heat of vaporization - is a kind of latent heat where liquid is converted to a gas (water fogs)
2.6 Heat of fusion - is a kind of latent heat where solid is converted to a liquid

9. 2. Chemistry & Physics of Fire
Sublimation – Under certain circumstances some materials can change from the solid to the vapor state and visa versa, this usually occurs at pressures below atmospheric.
Heat of Combustion is the amount of heat released when something burns
Units are: BTU/LB Joules/g

10. 3. Heat Transfer
3.1. Basic Principle: Heat energy always flows from hot to cold or from higher energy state to lower.
Heat transfer implies a rate and the symbol is “I”
I = Q/t
Units: BTU/HR or J/sec.

11. 3. Heat Transfer 3.2. Three major mechanisms of heat transfer
Conduction
Convection
Radiation
3.3 Heat Conduction
3.3.1 Heat transfer caused by molecules vibrating and colliding with other molecules transferring their kinetic energy

12. 3. Heat Transfer
Factors that influence heat transfer via conduction:
Effects of distance upon heat transfer by conduction
Effects of cross sectional area on heat transfer
Effects of composition on heat transfer
k - Coefficient of thermal conductivity
units: BTU/hr ft ºF

13. 3. Heat Transfer 3.3.3. Fourier’s Law of Heat Conduction Icd = k A Tx
Units: BTU/hr or Joules/sec
Heat Insulators

14. CONDUCTION VS 2-3 Vertical Horizontal
Point-to-Point Transfer of Heat Energy from One Body to Another by a Heat-Conducting Medium

15. 3. Heat Transfer 3.4. Heat Transfer by Convection
3.4.1 Heat transfer because of the movement of a fluid (air) containing the heat
"Hot Air Rises"  Natural Convection
The rate of heat transfer via convection is influenced by several factors

16. 3. Heat Transfer 3.4.5. Newton‘s Law of Cooling
Convection Heat Transfer Coefficient
Symbol & Units (h) BTU or Joules
hr. ft2 ºF sec.m2ºC
Newton‘s Law of Cooling
Formula: Icv = h AT

17. Movement of Heated Liquids or Gases
VS 2-4
CONVECTION
Heat Transferred by
Movement of Heated Liquids or Gases

18. 3. Heat Transfer 3.5. Radiant Heat Transfer
Heat transfer via electromagnetic waves
Radiant heat transfer (emission) depends on:
The nature of the surface (emissivity e)
The distance between the radiation source and the object it strikes

19. VS 2-5
RADIATION
Electromagnetic Waves Traveling Through Space Until They Reach a Solid Object

20. 4. Combustion
4.1. Combustion: is a rapid oxidation accompanied by the emission of heat & light
Oxidation - the chemical combination of an atom or molecule with oxygen and the chemical bonds contain energy.

21. 4. Combustion 4.2. Key Principles of Combustion
Heat Energy necessary to initiate combustion
The reaction is self-sustaining once the ignition source is provided
For combustion to occur you must have a:
a. fuel
b. oxidizing agent
c. heat to produce free radicals
d. uninhibited free radical combination

22. Chemical Chain Reaction Chemical Chain Reaction
VS 2-7
COMBUSTION
The Fire Tetrahedron
Reducing Agent (Fuel)
Oxidizing Agent
Heat
Chemical Chain Reaction
Oxidizing Agent
Reducing Agent (Fuel)
Heat
Chemical Chain Reaction

23. PRODUCTS OF COMBUSTION
VS 2-23
PRODUCTS OF COMBUSTION
Carbon Monoxide
Carbon Particles
4. SMOKE
3. FLAME
2. HEAT
1. LIGHT
Sulfur Dioxide
Hydrogen Cyanide
Flammable Vapors
Water Vapor
Carbon Dioxide
Fuel
Oxygen
Oxygen

24. 4. Combustion
4.3. Products of Combustion
Heat
Smoke

25. 4. Combustion 4.3. Products of Combustion 4.3.3. Fire Gases
Light - Flaming   

26. 5. Rates of Combustion 5.1 Flammable Gas 5.2 Flammable Liquid
5.3 Flammable Solid

27. 6.Unique Combustion Phenomena
6.1. Explosion- is the rapid
expansion of a gas that converts
the potential energy of the gas
to kinetic energy.
Sources of explosions in industry
Fuels (50%)
Flammable Liquid Vapors (12%)
Trapped Steam (7%)
Gas Leakage (6%)
Rupture of Pressurized Equipment (6%)

28. 6. Unique Combustion Phenomena
6.2. Deflagration- is the burning of a gas or aerosol that is characterized by a combustion wave
6.3. Detonation - the burning of a gas or aerosol that is characterized by a shock wave

29. 6. Unique Combustion Phenomena
6.4. Flashover
6.5 Backdraft
6.6. BLEVE

30. VS 2-18
FLASHOVER

31. BACKDRAFT VS 2-22b PRE-BACKDRAFT BACKDRAFT • Low Oxygen • High Heat
Smoldering Fire
• High fuel vapor
concentrations
PRE-BACKDRAFT
• Introduction of oxygen causes fire of explosive force
BACKDRAFT