Fire Detection, Protection, and Suppression Systems

Fire Detection, Protection, and Suppression Systems

Fire Detection, Protection, and Suppression SystemsExplain why all Fire fighters should have a basic understanding of Fire Protection systems. Describe the basic components and functions of a Fire Alarm  system.

Fire Detection, Protection, and Suppression Systems
Fire Detection, Protection, and Suppression Systems

Fire Detection, Protection, and Suppression Systems 

Objectives 

  • Explain why all fire fighters should have a basic understanding of fire protection systems.
  • Describe the basic components and functions of a fire alarm system. 
  • Describe the basic types of fire alarm initiation devices and where each type is most suitable.
  • Describe the fire department’s role in resetting fire alarms.
  • Explain the different ways that fire alarms may be transmitted to the fire department.
  •  Identify the four different types of sprinkler heads. 
  • Identify the different styles of indicating valves.
  • Describe the operation and application of the following types of automatic sprinkler systems:
  1. Wet-pipe system
  2. Dry-pipe system
  3. Preaction system
  4. Deluge system
  • Describe when and how water is shut off to a building’s sprinkler system and how to stop water at a single sprinkler head.
  • Describe the differences between commercial and residential sprinkler systems.
  • Identify the three types of standpipes and the differences among them.
  • Describe two problems that fire fighters can encounter when using a standpipe in a high-rise building.
  • Identify the hazards that specialized extinguishing systems can pose to responding fire fighters.

Introduction–Fire Fighter II Standard 

  • Fire prevention and building codes require that most new structures have some sort of fire protection system installed. 
  • Understanding how these systems operate is important for fire fighter safety and effective customer service. 
  • From a safety standpoint: The operations and limitations of fire detection and suppression systems .
  • From a customer service standpoint: 
  1. Help dispel misconceptions about fire protection systems. 
  2. Advise building owners and occupants after an alarm is sounded.

False alarms 

  • Sensors record an error somewhere in the system 
  • Detectors too close to the kitchen 
  • People become used to nuisance alarms and fail to respond accordingly .

Fire Alarm and Detection Systems–Fire Fighter II Standard 

  • A fire detection system recognizes when a fire is occurring and activates the fire alarm system .
  1. Alerts occupants 
  2. May alert the fire department 
  3. May automatically activate fire suppression systems
  • Fire alarm and detection systems can be very simple or very complex. 
           - These systems generally have the same basic components.
  • Three basic components in a fire alarm system:
  1. Alarm initiation device 
  2. Alarm notification device
  3. Control panel.

Fire Alarm System Control Panels–Fire Fighter II Standard 

  • Serves as the “brain” of the system
  • Manages and monitors the proper operation of the system
  •  Can indicate the source of an alarm 
  • Also manages primary power supply and provides backup power supply for the system.
Control Panels

  • May perform additional functions, and may interface with other systems and facilities.
  • Vary greatly depending on manufacturer and age of system.
  • Silence the alarm and reset the system .
  • Many buildings have an additional display panel, called a remote annunciator, in a separate location.
  • In some systems, a battery in the fire alarm control panel will automatically activate when the external power is interrupted.

Residential Fire Alarm Systems – Fire Fighter II Standard

Smoke Detector

  • Single-station smoke alarm most common type of residential fire alarm system 
  • Includes both a smoke detection device and an audible alarm within a single unit
  • Smoke alarms can be battery powered or hard-wired to a 110-volt electrical system. 
  • Up -to -date codes require new homes to have a smoke alarm in every bedroom and on every floor level.
  • Many home fire alarm systems are part of security systems.

Ionization vs. Photoelectric Smoke Detectors–Fire Fighter II Standard


Photoelectric Smoke Detectors


  • Ionization detectors are triggered by the invisible products of combustion.
  • Photoelectric detectors are triggered by the visible products of combustion.

Alarm Initiating Devices–Fire Fighter II Standard

  • Components that activate a fire alarm system
  1. Manual initiation devices require human activation.
  2. Automatic devices function without human intervention.

Manual Initiation Devices–Fire Fighter II Standard

Manual Initiation

  1. Designed so that building occupants can activate the fire alarm system
  2. Primary manual initiation device is the manual fire alarm box, or manual pull station.

Double-Action Pull Stations–Fire Fighter II Standard 


Action Pull Stations

  1. Designed to prevent malicious false alarms, is covered with a piece of clear plastic
  2. Often used in areas where malicious false alarms frequently occur.

Automatic Initiating Devices–Fire Fighter II Standard 

  • Designed to function without human intervention 
  • Can use several different types of detectors 
  1. Some detectors activated by smoke or by invisible products of combustion
  2. Others react to heat, light produced by an open flame, or specific gases.

Smoke Detectors–Fire Fighter II Standard 



  • Designed to sense the presence of smoke 
  • Most common are ionization and photoelectric detectors.

Heat Detectors–Fire Fighter II Standard 

  • Can provide property protection, but cannot provide reliable life-safety protection
  • Generally used in situations where smoke alarms cannot be used
  • Often installed in unheated areas
  • Generally very reliable and less prone to false alarms than smoke alarms

Fixed Temperature Heat Detectors–Fire Fighter II Standard 


Heat Detector
Heat Detector 

  • Designed to operate at a preset temperature
  • Usually use a metal alloy that will melt at the preset temperature

Rate-of-Rise Heat Detectors–Fire Fighter II Standard

  • Will activate if the temperature of the surrounding air rises more than a set amount in a given period of time
  • Most rate-of-rise heat detectors are self restoring.
  •  Generally respond faster to most fires than fixed-temperature heat detectors

Line Heat Detectors–Fire Fighter II Standard

  • Use wires or a sealed tube to sense heat 
  • One type has two wires inside, separated by an insulating material. 
  • Another measures changes in electrical resistance of a wire as it heats up.
  • The tube-type line heat detector has a sealed metal tube filled with air.

Flame Detectors–Fire Fighter II Standard


  • Specialized devices that detect the electromagnetic light waves produced by a flame
  • Complicated and expensive

Gas Detectors–Fire Fighter II Standard

  • Calibrated to detect the presence of a specific gas
  • Need regular calibration
  • Usually found only in specific commercial or industrial applications

Air Sampling Detectors–Fire Fighter II Standard


  • Continuously capture air samples and measure the concentrations of specific gases or products of combustion

Alarm Initiation by Fire Suppression Systems–Fire Fighter II Standard



  •  System alerts building occupants and the fire department to a possible fire.
  • Ensures that someone is aware water is flowing, in case of an accidental discharge.

False, Unwanted, and Nuisance Alarms–Fire Fighter II Standard

  • Malicious false alarms
      – Individuals deliberately activate a fire alarm
  • Unwanted alarms
– Alarm is activated by a condition that is not really an emergency
  • Nuisance alarms 
   – Improper functioning of an alarm system

Alarm Notification Appliances – Fire Fighter II Standard

  • Produce an audible signal when fire alarm is activated
  • Some signals play a recorded announcement in conjunction with the temporal-3 pattern.
  • Many new systems incorporate visual notification devices.

Alarm Notification Appliances – Fire Fighter II Standard


Other Fire Alarm Functions–Fire Fighter II Standard

  • May also control other building functions, such as air-handling systems, fire doors, and elevators
  • Responding fire personnel must understand which building functions are being controlled by the fire alarm.

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