What is a Fire Suppression System?
Fire incidents, especially in commercial buildings and factories, present considerable risks. A minor spark can escalate into a major calamity, leading to irreparable damage to property, resources, and, more importantly, human lives.
A fire protection system is at the heart of fire safety, specifically designed to combat these unforeseen situations. Among these, fire suppression systems, also known as special hazard systems, stand out due to their efficiency and comprehensive approach to special hazards. Special hazards refer to areas or items in a building or facility that are especially vulnerable or can cause a rapid spread of fire.
Keep reading to gain insight on how fire suppression systems work, the various types available, fire suppression systems maintenance and their significance in ensuring optimal fire safety.
How Does a Fire Suppression System Work?
A fire suppression system is designed to detect and combat fire in its early stages. Its key components include control valves, piping, external alarms, nozzles, smoke detectors, flame detectors, fire indicator panels, fire brigade panels, fire sprinkler heads, and the emergency warning system. Here's a simplified overview of how this intricate system operates:
- Fire Detection: Using smoke and flame detectors, the system quickly identifies any fire-related emergency.
- System Activation: Depending on its design, the system can be activated automatically (what is known as an automatic fire suppression system) or manually. This signals the system to prepare to combat the fire.
- Suppression Agent: Depending on the type of fire and the system, a specific suppression agent is released to neutralise the fire.
- Fire Extinguishing: The suppression agent extinguishes or controls the fire, preventing its spread.
- Fire Alarm System and Warning Notification: At the time of detection, a fire alarm system is also activated, warning the occupants about the fire and ensuring their safety. It may also notify firefighters to come put out the fire.
- System Monitoring and Shut Down: Post activation, the system continues to monitor the environment for any residual fire or smoke.
Types of Fire Suppression Systems
Fire suppression systems can be classified based on various factors. For example, they differ by the suppression agents used [i.e. water, foam, gas, or chemicals]. They also differ based on the type of fire hazard or fire class being addressed [e.g. electrical fires or those caused by flammable liquids]. Lastly, special hazard systems also differ by mode of operation. These include:
- wet pipe system (always filled with water)
- dry pipe system (filled with pressurised air and water flows upon activation only)
- deluge system (follows dry pipe mechanism but with open nozzles that can be used where rapid fire spread is a concern)
- pre-action (follows the dry pipe mechanism with an electric pre-action valve with a two-step process to prevent accidental activation)
Consider the following key types of fire suppression systems used in commercial settings.
Gas Fire Suppression System
Gas based fire suppression systems use inert gases to extinguish fires. These systems work by reducing the oxygen level in a room to a point where the fire can no longer be sustained but is still safe for humans.
CO2 Fire Suppression System
The carbon dioxide fire suppression system, a kind of gas-based fire system, uses carbon dioxide as its primary extinguishing agent.
The system displaces oxygen, making it impossible for the fire to sustain. CO2 systems are beneficial when water could damage sensitive equipment or worsen fires, like with electrical fires in data centres.
While effective, CO2 can harm humans in high concentrations, and requires adequate safety measures when used.
Clean Agent Fire Suppression System
Clean agent fire suppression systems are advanced fire-fighting mechanisms that use environmentally friendly gases as the suppressing medium.
Unlike traditional methods, clean agents leave no residue post-application.
They work by removing heat and breaking the chemical chain reaction that fuels a fire, quickly extinguishing it without causing damage to sensitive equipment or electronics. These systems are commonly found in spaces where water-based solutions may cause harm, such as data centres, server rooms, art galleries, and archives.
The main advantage of using a clean agent system is its non-destructive nature. As the system doesn't rely on water or foam, there's no clean-up required, preventing potential water damage to assets. Moreover, clean agents are typically safe for humans, ensuring minimal health risks during accidental discharge.
Water-Based Fire Suppression System
A water-based suppression system has a history of safeguarding buildings and lives and is the most common type of fire suppression system used. Its natural, accessible, and effective properties make it a first choice for many.
The two main systems of water-based suppression are the automatic sprinkler systems and water mist systems.
- Automatic Fire Sprinkler Systems: Found abundantly in commercial and residential setups, these systems spring into action, releasing water once a specific temperature threshold is reached. They are known for simplicity, reliability, and economic viability.
- Fire Suppression Mist Systems: Water mist systems unleash fine droplets of water, which cover a larger surface area. The resultant mist supports rapid heat absorption, causing a cooling effect and preventing fire progression. Their unique design and function make them ideal for spaces that must avoid water damage.
While these systems are good at suppressing fire, their activation might require a thorough clean-up and risks damaging equipment.
Foam Fire Suppression System
Foam fire suppression systems tackle fires that water alone can't suppress, especially those involving flammable liquids.
These systems combine water, foam concentrates, and air to produce a foam blanket that cools the fire and separates the flames from the fuel source.
The foam spreads rapidly, covering the fire and preventing oxygen from reaching it. This not only suppresses the fire but also prevents re-ignition. Due to their effectiveness, foam systems are primarily used in places like aircraft hangars, fuel storage facilities, and certain industrial settings where flammable liquids are present.
Chemical Fire Suppression System
Chemical fire suppression systems suppress fires by using chemical agents.
These agents effectively interrupt the chemical reactions within the fire, breaking its cycle. Chemical systems generally fall into two main categories: wet chemical and dry chemical.
- Wet Chemical Systems: These systems use a wet chemical solution to suppress fires. When activated, the system releases a fine mist that cools the fire and forms a foam blanket, starving the fire of oxygen.
Wet chemical systems are especially effective in kitchen environments, where grease fires are common.
- Dry Chemical Systems: These systems use a powdered extinguishing agent. This powder blankets the fire and disrupts the chemical reaction of the fire triangle (heat, fuel, and oxygen).
Due to their versatility, dry chemical systems are popular in various settings, including industrial sites and vehicle applications.
When is a Fire Suppression System Required?
Fire suppression systems are important in spaces where the risk of fire is significant or where the potential damage would be catastrophic. Some of the critical areas include:
- Manufacturing Sites and Factories: These spaces often contain highly combustible materials.
- Warehouses: Large storage spaces with potentially flammable products.
- Commercial Kitchens: The risk of grease fires makes suppression systems essential.
- Data & Server Rooms: Protecting digital assets and critical infrastructure from fire.
- Hospitals: Ensuring patient safety and protection of vital equipment and medicines.
- Vehicles: Due to fuel tanks or transport of hazardous or explosive goods.
Fire Suppression System Servicing
Safety in buildings is important, making fire suppression systems indispensable. Adherence to Australian Standards, especially AS1851, is crucial. But what is the frequency of fire suppression system inspection?
This standard requires an annual Enclosure Integrity test, identifying potential leakages that compromise system efficiency. Comprising multiple intricate components, each element of a fire suppression system demands regular inspection and maintenance.
Monthly evaluations primarily focus on potential damages to external alarms, fire indicator panels, and the integrity of wiring and batteries. In contrast, annual assessments are more detailed.
They incorporate room integrity tests and involve simulating a fire to check the responsiveness and accuracy of detection sensors, visual aids, and other associated systems.
Regular fire safety Inspection is crucial to ensure the efficiency of any fire suppression system. Regular checks ensure the system functions optimally when needed, safeguarding lives and assets.
Ensuring Fire Safety
Staying prepared for fire is key, and building owners and managers must ensure that their building’s special hazard systems are not just updated but also easily accessible and rigorously maintained.
Adherence to Australian standards encompasses everything, including fire extinguishers, fire blankets, fire hydrants etc. These standards have been established for a reason: to ensure optimal protection against potential fire threats. With a proactive approach to testing and maintaining fire suppression systems, both the safety of individuals and protection of property are possible.