An Introduction to Fire Alarm Systems

Posted on: July 18, 2017

Learn about the components and types of fire alarm systems that protect lives and property

Fire alarm systems are perhaps the most essential elements of any building’s life safety systems. Not only do they save countless lives every year, they often regulate other systems in the building and property owners save huge amounts of money by reducing damage to their structures. Let’s review the components of different fire alarm systems and how each can influence safety and function.

What are the main components of a fire alarm system?

A fire alarm system has three main components: the fire alarm control panel (FACP), the input device or devices (also known as initiation devices) – such as a pull station, a smoke detector, or a water flow switch on a sprinkler system – and a notification device, such as a horn, speaker, bell, or siren.

The importance of fire alarm control panels

Fire alarm control panels are the “brain” of the fire alarm system that allow personnel to activate or deactivate the entire system at will. FACPs are manufactured in a variety of shapes, sizes, and formats depending on the manufacturer and the panel’s intended scope of use. The smallest are intended to cover only small rooms or structures, while the largest panels may be designed to cover large networks of multiple buildings.

Manual vs. automatic initiation devices

Manual devices, like pull stations, must be activated by a person. Variations include single action (pull one handle to activate), dual action (push-in and pull-down a handle or lift/break glass and then pull handle), and institutional (must insert a key to activate; often used in settings like jails). The Americans with Disabilities Act mandates that all of these devices must be accessible to people in wheelchairs.

Automatic devices, unlike their manual counterparts, do not need a person’s input. HVAC duct smoke detectors are designed to detect smoke and activate when a certain level is reached. Heat detectors will automatically activate if the temperature around them rises too quickly in a certain period of time or if the overall temperature reaches a set range.

Other popular automatic devices include beam smoke detectors and fire sprinkler water flow switches. Beam smoke detectors cover large areas such as atriums and will automatically activate if the laser beam between the transmitter and receiver is obscured, while water flow switches automatically detect water movement in the sprinkler pipes. Other types of detectors include laser detectors, video detectors, flame detectors, line type detectors, air sample detectors, gas detectors, spark/ember detectors, and carbon monoxide detectors.

Notification devices

Notification devices are intended to alert building occupants of a fire and allow them to vacate the building or take other emergency action. Once a fire alarm signal is received by the FACP, the panel will sound or beep locally. The FACP then activates the notification devices connected to it, which many include horns, sirens, bells, lights, warning signs, or pre-recorded messages on fire alarm speakers. For larger buildings or networks of buildings, mass notification systems can also be incorporated into the system.

Fire alarm control functions

Depending on its individual functionality, a fire alarm system is often the heart of a structure’s entire life safety apparatus. In large buildings, the fire alarm is the core of all the emergency systems and must interface with many of the building’s mechanical systems, including:

  • Controlling the elevators and locking them out for first responder use only
  • Shutting down HVAC units to prevent the spread of smoke
  • Unlocking security doors to allow exit from the building (and access for first responders)
  • Controlling mechanical evacuation systems to vent smoke
  • Providing notification to occupants about to the location of the fire and what exits should be used to evacuate
  • Shutting off natural gas lines to kitchens to prevent explosions
  • Shutting off sound systems so that emergency messages can be communicated

Types of fire alarm systems

According to the National Fire Protection Association Handbook, there are four main types of fire alarm systems:

1. A local system is located at a property and is not monitored by a central station. Any alarm will only notify the property’s occupants, meaning that an individual would need to call 911 for help in an emergency.

2. A proprietary system is located at a property and is only monitored by the local occupants and staff, which includes a group of first responders.

3. A remote system is located at the property but is monitored by a central station. An alarm signal would be sent to the central station and they notify first responders.

4. A central station is located at a property, it is monitored by a central station, and it has a service contract with a company for all its repairs, tests, and inspections.

Is your system really a fire alarm system? And is it properly connected?

It’s important to note that just because your building has a red box on the wall doesn’t mean that it’s a true fire alarm. Some buildings are allowed to have fire alarm system panels that simply monitor the fire sprinklers in a building, as well as a smoke detector. Other buildings may only have an elevator recall panel – but since this is intended only for elevator recall, this is not a true fire alarm system either. Extinguishing systems for computer rooms may also be easily mistaken for fire alarm systems.

It’s also essential to make sure your system can communicate with monitoring stations, so that if telephone lines, Internet access, cell-phone towers, or radio networks are not operational, it will still function correctly. No matter what type of fire alarm you have in place, it’s important to make sure that it’s the right setup for your structure, and that it’s consistently maintained, repaired, and inspected to protect your property and people.

If you have questions about your fire alarm, or you think your life safety systems need to be updated, repaired, inspected, or replaced, contact LifeSafety Management at (800) 330-1158 or fill out our contact form to set up a free assessment by our experienced team of professionals.