Comparison of Automatic Fire Suppression Systems (AFSS)
Analysis of fire extinguishing technologies and systems |
The Technical Regulations on Fire Safety Requirements stipulate that all protected facilities must have a fire safety system in place. Automatic Fire Extinguishing Systems (AFSS) are a critical component of these systems. The analysis of fire extinguishing technologies and systems was conducted based on criteria defined in accordance with GOST 12.1.004-91 "Occupational Safety Standards System (OSSS). Fire Safety. General Requirements." Automatic Fire Extinguishing Systems must fulfill the following requirements:
This analysis examines the primary fire extinguishing methods, extinguishing agents, mechanisms of action, efficiency, and the economic, environmental, and operational characteristics of automatic fire extinguishing systems. |
The mechanism of water-based fire extinguishing relies on the following |
Sprinkler systems release the extinguishing agent locally at the ignition site when the temperature-sensitive release mechanism in the sprinkler head is activated. These systems are suitable for facilities where the ambient temperature is maintained above 5°C, such as in water-filled systems, control assemblies, and pump stations. Deluge fire extinguishing systems operate across the entire protected area. These systems consist of open sprinkler heads, which are activated by a solenoid valve controlled by a fire alarm system. Deluge systems are also commonly used to create water curtains, effectively isolating fire-affected zones to prevent the spread of fire to other parts of the building. Mechanism of Suppression:The fire-extinguishing effect of water is based on its cooling and insulating properties. Upon contact with the fire, water evaporates into steam, displacing atmospheric oxygen and isolating the combustion surface. As a result, the burning process is effectively stopped. Suppression occurs across the surface area of the protected space, targeting the fire directly. Fire Suppression Efficiency:Fire Extinguishing for Class A Fires: Water-based Fire Extinguishing Systems are primarily used to protect large areas with high ceilings. The use of water for fire suppression is subject to the following physical limitations: water-based systems cannot be used in environments with temperatures below freezing; water is unsuitable for extinguishing fires involving electrical installations. Air-pipe systems are known for their high inertia. Equipment Costs:High. Implementation requires significant infrastructure, including: Construction of pump stations and firewater reservoirs. Underground pipeline installation with additional protection beneath roadways. Drainage systems. Operational Costs:High water consumption during fire suppression. Heating of firewater reservoirs in regions with cold climates. Reliable power supply (Category I reliability) is mandatory. Approval from water authorities for required flow rates and pressure. Potential Damage to Protected Facilities and Environment:Water is safe and non-toxic but poses a high risk of secondary damage due to flooding of premises and valuable assets. Cleanup after system activation requires significant labor and resources. |
Foam Fire Extinguishing Systems |
Foam Fire Extinguishing Systems are designed for extinguishing flammable and combustible liquids in tanks, flammable materials, and petroleum products, both indoors and outdoors. These systems are effective only in environments with positive ambient temperatures. Mechanism of Suppression:Foam suppression systems utilize the cooling properties of water to reduce the temperature of burning materials and the ability of foam to cover these materials, cutting off oxygen supply to the combustion zone. The properties of foam-based fire extinguishing enable it to extinguish not only solid materials but also flammable liquids. By simultaneously cutting off oxygen supply to the combustion zone and cooling the fire source, foam effectively disrupts the combustion process. A defining feature of such systems is the inclusion of a foam concentrate tank and dosing equipment, with a mandatory requirement for the separate storage of the extinguishing agent components. Fire Suppression Efficiency:Foam suppression systems are effective for extinguishing Class A and Class B fires, including those in non-sealed spaces. They allow for the customization of the extinguishing agent’s properties, such as expansion ratio, chemical composition, and application method, to suit specific fire load requirements. However, these systems can be challenging to use in areas with electrical installations. Additionally, they rely heavily on water supply sources and are characterized by high inertia. Equipment Costs:High. Implementation requires significant infrastructure, including: Construction of pump stations and firewater reservoirs. Underground pipeline installation with additional protection beneath roadways. Drainage systems. Operational Costs:Regular replacement and proper disposal of foam concentrate are necessary. Foam concentrates with fluorine-based film-forming agents require annual laboratory testing. Furthermore, maintaining a positive system temperature is critical to ensure functionality. Potential Damage to Protected Facilities and Environment:Foam's high corrosive activity substantially raises the costs of restoring the fire extinguishing system, as well as the protected premises and equipment. Furthermore, proper disposal of environmentally hazardous byproducts is mandatory. |
Water Mist Fire Extinguishing Systems |
Water mist fire extinguishing systems are designed for surface and localized fire extinguishing of Class A and Class B fires (in accordance with GOST 27331) and for electrical installations operating at voltages specified in the technical documentation. Mechanism of Suppression:Water mist systems disperse water into droplets no larger than 150 microns. In some configurations, surfactants (SAS) may be added. The suppression mechanism relies on water’s ability to cool the burning material and isolate it by generating steam, which interrupts the combustion process. Suppression in this case occurs across the surface of the protected area. Fire Suppression Efficiency:Water mist systems are suitable for fire suppression in administrative buildings, offices, banks, archives, museums, server rooms, and electrical equipment under voltage, provided all safety regulations are strictly observed. It is crucial to ensure that modular and aggregate water mist systems are used only after passing the required fire testing. Furthermore, the design of these systems must comply with technical specifications developed specifically for the protected facility or a group of similar facilities. Equipment Costs:Medium Operational Costs:Water mist systems feature minimal water consumption for fire suppression and require specialized maintenance. Their application is restricted to an operational temperature range of +5°C to +50°C. Potential Damage to Protected Facilities and Environment:Gas fire suppression systems are designed to be safe for both humans and the environment. Their use of minimal extinguishing agents (EA) significantly reduces the risk of secondary damage, such as water exposure to premises or valuable assets. |
Gas Fire Extinguishing Systems |
These systems are effective for extinguishing Class A, B, and C fires (as defined by GOST 27331) and are suitable for use with electrical equipment. Gas fire suppression systems should not be used to extinguish fires involving: Fibrous, loose, porous, or other combustible materials that are prone to self-ignition or smoldering within their volume (e.g., wood shavings, cotton, grass meal). Chemical substances, mixtures, or polymeric materials that exhibit smoldering or combustion without access to air. Mechanism of Suppression:Gas fire suppression systems operate by reducing the oxygen concentration in the combustion zone through the introduction of non-combustible gas. For liquefied gases, their release from the cylinder results in a significant temperature drop, which further cools the combustion zone. These systems utilize a volumetric suppression method. Fire Suppression Efficiency:Gas suppression systems are particularly suitable for protecting server rooms, data centers, and other spaces housing electronic equipment. Halocarbons and carbon dioxide, being 2 to 4 times heavier than air, distribute from the floor upwards, ensuring thorough coverage until the required fire-extinguishing concentration is achieved. For localized suppression, a CO₂ concentration of 6.0 kg/m³ is required. These systems are recommended for spaces with a volume of up to 2000 m³. To ensure proper containment of the extinguishing gas, the room must meet the airtightness requirements specified in Appendix D of SP 5.13.130.2009. Equipment Costs:Gas-based automatic fire suppression systems (AFSS) are positioned in the premium price segment. This is largely due to the high cost of the suppression modules and the need for numerous supplementary components, including weight stands, distribution devices, and piping systems. In centralized systems, storage cylinders must be located in dedicated fire extinguishing stations. For modular installations using liquefied gases, refrigeration units and electric heaters are often necessary. While the initial investment is relatively high, gas fire extinguishing systems are a cost-effective solution for enterprises and organizations that prioritize minimizing the impact of extinguishing agents on protected equipment and valuable assets. Operational Costs:Gas fire suppression systems must be installed in heated facilities or block containers. These systems operate within a temperature range of -50°C to +50°C. To maintain the necessary pressure in liquefied gas storage units (LGSU), continuous cooling or heating is required. Potential Damage to Protected Facilities and Environment:The primary disadvantage of gas fire extinguishing systems is the potential risk they pose to human safety. |
Powder Fire Extinguishing Systems |
Powder fire extinguishing systems are commonly used to extinguish Class A, B, and C fires, as well as fires involving electrical equipment. Mechanism of Suppression:Powder fire suppression systems utilize extinguishing powder as the primary agent. Suppression is achieved by delivering a finely dispersed powder directly to the fire source. The powder is expelled under pressure, either from a pre-charged cylinder containing gas or through the activation of a gas generator integrated within the storage container. Fire Suppression Efficiency:Powder fire suppression systems are highly effective for suppressing fires over a defined area, provided the fire source lies within the system's dispersion coverage. For complex spaces with shadow zones or obstructions, additional Powder Fire-Extinguishing Modules (PFSM) should be installed to ensure adequate coverage. These systems are unsuitable for extinguishing combustible materials prone to self-ignition or smoldering within their volume, such as wood shavings, cotton, grass meal, and paper. They should not be used for chemical substances, mixtures, pyrophoric materials, or polymers that smolder or burn without access to air. The application of extensive piping systems for powder distribution is limited. Equipment Costs:Powder Fire Extinguishing Systems are typically positioned in the mid-to-lower price range. However, in areas with shadow zones, additional Powder Fire-Extinguishing Modules (PFSM) may be required to provide comprehensive coverage. Operational Costs:Ceiling-mounted powder modules are relatively complex and labor-intensive to service during routine maintenance. The service life of the extinguishing powder is generally 5 years, though certain models may offer an extended lifespan of up to 10 years. These systems are available in both single-use and rechargeable configurations. A significant advantage of powder fire suppression systems is their ability to function in unheated environments, with an operational temperature range of -50°C to +50°C. Potential Damage to Protected Facilities and Environment:Powder Fire Extinguishing Systems pose direct inhalation risks to humans and significantly reduce visibility within protected areas during operation. The powder composition causes minimal impact on protected items, materials, and equipment. However, these systems are not recommended for server rooms, data centers, or other environments housing sensitive electronic equipment. |
Powder-gas fire-extinguishing systems |
Powder-gas fire-extinguishing systems are designed for both volumetric and localized suppression of Class A, B, and C fires, including fires involving electrical equipment, without limitations on dielectric breakdown voltage. Mechanism of Suppression:Powder-gas mixtures utilize all primary fire suppression mechanisms: cooling; isolation; inhibition and dilution. Fire Suppression Efficiency:Powder-gas fire-extinguishing systems provide rapid response due to their minimal activation inertia and high delivery rate of extinguishing agents. The powder, carried by the gas mixture, disperses quickly and uniformly throughout the protected area. Equipment Costs:Powder-gas fire suppression systems are positioned in the mid-range price segment. Thanks to their efficient extinguishing concentration of approximately 0.2 kg/m³, they offer a cost-effective solution. Operational Costs:It does not require a water supply or heated facilities for installation and operates effectively within a temperature range of -50°C to +50°C. Modules have a service life of up to 10 years and can be recharged up to 10 times. Potential Damage to Protected Facilities and Environment:The powder-gas mixture is non-damaging to protected items, materials, equipment, or petroleum products. The composition is environmentally safe and does not pose risks to ecological systems. However, it can have direct inhalation effects on humans and significantly reduces visibility within protected areas during activation. |
Aerosol Fire Extinguishing Systems |
Aerosol Fire Extinguishing Systems are designed for volumetric suppression of Class A2 fires (non-smoldering solid materials such as plastics and rubber), Class B and C fires, as well as fires involving electrical equipment. Mechanism of Suppression:The system releases a mixture of inert gases and finely dispersed particles produced by the combustion of solid propellant into the protected area. This mixture reduces oxygen concentration and slows the oxidation reaction. Fire Suppression Efficiency:Aerosol fire suppression systems are not recommended for facilities handling flammable liquids (FL), combustible liquids (CL), or flammable gases, as the extinguishing agent exits the module at temperatures exceeding 300°C, which may exceed the autoignition temperature of many substances. It is particularly well-suited for protecting small, confined spaces such as engine compartments (in automotive, marine, and rail transport), cable ducts, electrical enclosures, safes, and similar applications. Equipment Costs:Due to the high temperatures generated during the release of the extinguishing agent, aerosol generators must be installed on non-combustible surfaces or mounted on specially designed brackets made from non-combustible materials. These systems can also be deployed autonomously, reducing the need for complex automation and associated costs. Operational Costs:Aerosol fire extinguishing generators are designed for single-use operation. They are capable of functioning in a wide temperature range from -50°C to +85°C. Potential Damage to Protected Facilities and Environment:The elevated temperatures near the nozzle during the combustion of the aerosol-forming compound can potentially ignite nearby materials, posing a risk of re-ignition. However, it can have direct inhalation effects on humans and significantly reduces visibility within protected areas during activation. Comparison Matrix for Automatic Fire Suppression Systems (AFSS) Evaluation Matrix for Automatic Fire Suppression Systems (AFSS) |