Basic Guide To Fire Alarms

fire alarms

Table of Contents

Fire alarms are designed to alert us about an emergency to take immediate action for the safety of the staff, employees and residents. Fire alarm systems can be easily found in public buildings, offices, and homes.

They are part of our daily lives, and no matter the type of detection, they help warn people so that they can take immediate action.

But what exactly is a fire alarm system, how it works, and what are its components? Let us discuss this in detail.

A Short History of Fire Alarms

Francis Robbins patented the first fire automatic alarm system in 1890. However, the design and technology have immensely evolved; George Andrew Darby invented the first heat and smoke battery-powered detectors after 12 years.

How Do they Work?

A fire alarm system has many types, each working in different ways. No matter the type, the key purpose of a fire alarm system is to alert the residents and the staff of a potential fire.

High-tech and advanced cameras alert the security officers, telling them the exact location of the fire or smoke. All these systems have control panels and a network of appliances and devices.

The functions can be described as the following:

  • Detection
  • Alerts
  • Monitoring
  • Controlling

To understand the system better, let’s go into detail to discuss the components of a fire alarm system.

fire alarm working

A List of Fire Alarm System Components

A fire alarm system contains many components, including the following:

  • Fire alarm control panel
  • Strobes or horns
  • Pull stations
  • Air aspirating smoke detectors
  • Notification devices
  • Smoke detectors
  • Duct detectors
  • Beam detectors
  • Audible devices
  • Initiation devices
  • Dialers or communicators
  • Water flow switches and tamper switches
  • Heat detectors

Here is how each component functions:

  • Control Panel

The control panel is the brain of a fire alarm system and is commonly known as FACU. This panel receives inputs from the devices and carries out the enlisted functions:

Sends a notification: If an issue occurs, the panel will receive signals and displays a notification on the panel, also known as output.

Elevator recall: The control panel or the FACU recalls and alerts the elevator that is taking people towards the fire, smoke or incident location.

HVAC system shutdown: If a fire alarm system detects smoke, it will instantly turn off the air handling unit so that smoke won’t spread to other areas of the premises.

Notifying alarm monitoring centre: The panel will alert the emergency services outside the facility, allowing them to respond immediately.

Minimising False Alarms

If a fire alarm system is poorly installed, designed or not regularly maintained, it will go off without sensing an emergency. In such a way, people won’t take the emergency seriously unless they smell smoke and see fire. Therefore, technology in the manufacturing industry has taken important steps to make the systems more efficient, reducing the chances of false alarms.

Types of Fire Alarm Panels

There are two types of fire alarm panels:

  • Addressable
  • Non-addressable

Addressable:  all addressable fire alarm panels have their separate address. This allows the owner to access the status of all the components. For example, a business owner can check the status and location of any component on the alarm panel display.

Non-Addressable: in this type, all systems put devices in the zone category. In an emergency, it will display something like “ALARM ZONE 3”, and the owner will have to go and check physically. For this reason, most people prefer buying addressable panels to check the precise location, handling it more quickly.

Advanced system panels also alert the officer’s station: however, most states do not allow these systems to be installed in facilities.

fire alarm working

Three States of a Fire Alarm System

Fire alarm panels display the state of the fire alarm system all the time in this way:

Normal: It means all the appliances, wiring, circuitry and devices are working in a tip-top condition

Alarm: In this state, the alarm is active.

Trouble: There could be many reasons for displaying this sign, such as short wiring occurring in the circuits or the phone line not working correctly.

  • Initiation Devices

These devices help initiate the alarm; like a fire alarm system, they are available in addressable and non-addressable means.

A water flow switch will be non-addressable but can be switched to addressable mode as the switches have special addresses to communicate with the system.

Other than a water flow switch, there are many imitation devices which include the following:

  • Pull stations and Duct detectors
  • Beam detectors
  • Smoke detectors and heat detectors
  • Tamper switches
  • Air aspirating detectors
  • Pull Stations

Many of you might be familiar with pull stations. It is manually operated, and the alarm is initiated when the handle is pulled. One of the great benefits of pull stations is that while smoke detectors detect the smoke a bit late, the evacuation can be done immediately if this is pulled manually. In such a way, anyone can reach safety immediately. These are available in various sizes and shapes and come with protective covers.

  • Smoke Detectors

In the case of smoke detection, a smoke detector sends out an alarm signal. These devices fall into one of two main categories, which depend on the sensor they use to identify smoke.

Ionization detectors: These detectors have two electrically charged plates between little amounts of radioactive material. Smoke atoms block the movement of ions between these two charged surfaces. When this occurs, the smoke detector is sounded.

Photoelectric Detectors: In their detection chamber, photoelectric detectors emit LED light beams. When smoke enters this chamber, the light beam is scattered, and some of it is diverted onto the photoelectric sensor of the detector. The smoke detector sounds when the sensor notices this light.

  • Duct Detectors

Duct detectors are installed in the heating ducts and air conditioning units. In the case of smoke detection, they instantly turn off all the units so that the smoke does not spread to all the rooms and areas.

heat dectector
  • Heat Detectors

There are two main types of heat detectors that react to heat as they contain sensors:

  • Fixed temperature heat detectors
  • Rate of rise heat detectors

Fixed temperature heat detectors: these heat detectors are turned on when the set limit exceeds of fixed temperature. They are further divided into two categories; linear detectors, which check the temperature of the entire area, and spot detectors, which detect the heat of one precise location.

Rate of rise heat detectors: if a specified value or temperature rate is raised, the rate of rise heat detectors will go off.

  • Beam Detectors

These detectors emit a beam across the area, and the system will go off if the smoke comes in contact with the beam.

  • Air Aspirating or Air Sampling Smoke Detector

These systems are highly sensitive; they can detect even a minute change in the air composition.

  • Water Flow Switches

Water flow switches use paddles inside pipework filled with water that reacts when water flows. Furthermore, sprinkler systems are designed to function even if just one sprinkler is supplying water.

  • Tamper Switches

This is a supervisory initiating device, and the alarm triggers if someone moves the valve from its actual position.

  • Notification Devices

This device simply sends an alert in the form of a notification to the home or business owner.

  • Audible Devices

These devices include horns, bells and sirens.

  • Strobes or Horns

Strobes use flashlights and blare a siren to send notifications.

  • Dialers or Communicators

Some systems include communicators to send an alert to the emergency station. Communicators use the internet, phone lines or radio signals to contact.

Types of Fire Alarms

Some common types of alarm systems include the following:

  • Non-Addressable Fire Alarm System (Conventional)
  • Analogue Addressable Fire Alarm System
  • Radio Fire Alarm System (Wireless)
  • Radio & Analogue Fire Hybrid Alarm System
install fire alarm

Do You Need Certification to Install a Fire Alarm System?

The simple answer to the question would be yes. Here are the types of certifications required for the fire alarm installation:

  • Design Certificate
  • Installation Certificate
  • Commissioning Certificate
  • Variation Certificate
  • Acceptance Certificate
  • Modification Certificate
  • Maintenance Certificate

British Standards BS 5839-1:2017

These are the essential codes and guidelines for fire alarm systems and fire detection systems for buildings across the UK. 

These codes state the guidelines for the maintenance, repair, design, installation and planning for all the dwellings and buildings in the UK.

Though it does not explain if you should install a fire system or not; however, to comply with the rules and regulations, a professional should assess and evaluate the premises thoroughly.

Understanding Common Terms and Phrases

Here is an explanation of some key terms related to the fire alarm system software:

  • Open Protocol

These manufacturers and companies let anyone buy their software.

  • Managed Protocol

In managed protocol, companies do not let anyone buy their software. Instead, they appoint official distributors, allowing clients to choose accordingly.

  • Closed Protocol

The third and last one is closed protocol, in which company officials only have access to the software. They do not have distributors; the company is the only one to contact for maintenance and repair of the systems.

Share This :

Send us a message

Have Any Question?

Feel free to contact us via mobile phone or email.