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CARBON DIOXIDE (CO₂) FIRE EXTINGUISHING SYSTEMS

What is a Carbon Dioxide Fire Extinguishing System?

Carbon dioxide (CO₂) fire extinguishing systems are automatic gas fire extinguishing systems used to protect high-risk areas such as electrical equipment, industrial machines, energy facilities, and locations with flammable and combustible materials against fire. Carbon dioxide is a colorless, odorless, and electrically non-conductive extinguishing gas that has been used for fire extinguishing purposes since the early 1900s. CO₂ can be stored in high-pressure cylinders or in low-pressure tanks in applications where large amounts of extinguishing agent are required. CO₂ fire extinguishing systems work in conjunction with fire detection and control systems to ensure the fire is brought under control and extinguished at an early stage. The system design is carried out through engineering calculations considering the volume of the protected area, the fire load, the equipment used, the risk class, the extinguishing method, and relevant standards.

How Does a CO₂ Fire Extinguishing System Work?

The basic working principle of carbon dioxide fire extinguishing systems is to reduce the oxygen concentration necessary for the fire to continue. When a fire is detected by the fire detection system, the control panel activates the CO₂ extinguishing system according to a predetermined scenario. After the necessary alarm, warning, and safety steps are completed, CO₂ is directed from its storage cylinders or tank to the protected area via the piping system. When CO₂ spreads into the area, it lowers the oxygen concentration to a level where combustion cannot be sustained, thereby extinguishing the fire. In local applications, local fire control can be achieved by directing the gas specifically to a certain machine, equipment, or hazardous area. For the system to work properly, it is critically important that the gas is discharged in the correct amount and within the appropriate time. Therefore, CO₂ extinguishing systems require engineering calculations and professional application in accordance with relevant standards.

Extinguishing Principle of CO₂ Fire Extinguishing Systems

The extinguishing effect of carbon dioxide is primarily based on the principle of smothering, that is, reducing the oxygen concentration in the environment. The cooling effect that occurs during the discharge of the gas also contributes to bringing the fire under control. Because CO₂ is in a gaseous state, there is no need for extensive cleaning after extinguishment, unlike foam, water, or dry chemical agents. This feature can provide a significant advantage, especially in the protection of electrical equipment and high-value industrial machinery.

Features of CO₂ Fire Extinguishing Systems

  • It is a colorless and odorless extinguishing gas.
  • It is electrically non-conductive.
  • It can be used to protect electrical and electronic equipment in appropriate risk situations.
  • It leaves no solid or liquid extinguishant residue after extinguishment.
  • It can be used in total flooding extinguishing applications.
  • It is suitable for local application extinguishing.
  • It can be applied with single or multiple CO₂ cylinder groups.
  • Low-pressure tank systems can be used in facilities requiring large amounts of CO₂.
  • Refill operations can be widely performed.
  • The amount of extinguishing gas can be tracked with suitable monitoring systems.
  • It can offer suitable solutions for industrial applications with high fire risk.
  • It can be evaluated as an effective extinguishing solution especially in specific processes involving flammable and combustible materials.

High Pressure and Low Pressure CO₂ Systems

High Pressure CO₂ Systems

In high-pressure systems, carbon dioxide is stored in specially designed high-pressure cylinders. One or more cylinders can be used in the same system depending on the volume of the protected area and the fire risk. These systems can be preferred especially for medium and small-scale areas and applications aimed at protecting specific equipment.

Low Pressure CO₂ Systems

Low-pressure CO₂ tank systems can be used in large-scale industrial applications requiring high amounts of CO₂. These systems can be considered as an appropriate engineering solution in applications such as power generation facilities, large industrial processes, turbines, and process areas with high fire loads.

Total Flooding and Local Application CO₂ Extinguishing Systems

Total Flooding

In total flooding, the required amount of CO₂ is discharged into the entire protected area. The gas reaches the designed extinguishing concentration within the space, providing general control over the fire. This method can be evaluated in enclosed and controlled areas along with necessary safety precautions.

Local Application Extinguishing

In local extinguishing systems, CO₂ is directly aimed at a specific equipment or area carrying a fire risk. It can be used especially in large industrial machines, process equipment, turbines, and applications where specific fire hazards can be locally identified.

Application Areas

Generator Rooms Generator rooms
UPS and Uninterruptible Power Supply Rooms UPS and uninterruptible power supply rooms
Transformer Rooms and Substations Transformer rooms and substations
Low and Medium Voltage Electrical Rooms Low and medium voltage electrical rooms
Power Generation Facilities Power generation facilities
Hydroelectric Power Plants Hydroelectric power plants
Thermal Power Plants Thermal power plants
Turbine Systems Turbine systems
Natural Gas Engines Natural gas engines
Fuel Tanks and Fuel Systems Fuel tanks and fuel systems
Petrochemical Facilities Petrochemical facilities
Oil and Gas Facilities Oil and gas facilities
Ship Engine Rooms Ship engine rooms
Industrial Production Facilities Industrial production facilities
Process Areas with Flammable and Combustible Liquids Process areas with flammable and combustible liquids
Heavy Industrial Machinery Heavy industrial machinery
Process Equipment Process equipment
Electrical and Energy Infrastructure Areas Electrical and energy infrastructure areas

Can CO₂ Systems Be Used in Normally Occupied Areas?

Since high concentrations of CO₂ gas can pose a serious risk to human health, its use in areas where people are present requires special safety precautions. Therefore, when designing a CO₂ gas fire extinguishing system, it must be evaluated whether the protected area is continuously or temporarily occupied by people. In situations where it must be applied in occupied areas; fire alarms, audible and visual warning systems, pre-discharge warnings, time delays, emergency stop mechanisms, escape procedures, and necessary safety equipment are important parts of the system design. CO₂ systems should only be applied in accordance with proper engineering design and the requirements of relevant safety standards.

Advantages of CO₂ Fire Extinguishing Systems

The main reasons why carbon dioxide systems are preferred, especially in industrial applications, are that they leave no residue, are electrically non-conductive, are suitable for certain high fire risks, can be applied to large volumes, are suitable for local extinguishing, and reduce the need for cleaning after extinguishment.

CO₂ Fire Extinguishing System Design

For a CO₂ fire extinguishing system to operate reliably, an installation consisting merely of cylinders and nozzles is not sufficient. The entire system must be designed according to engineering principles for the risk to be protected. During the design phase; the volume of the protected area, fire class, fire load, properties of flammable and combustible materials, equipment to be protected, total flooding or local extinguishing method, required CO₂ amount, pipe diameters and piping route, nozzle placement, discharge time, cylinder or tank capacity, fire detection system, alarm and warning equipment, ventilation systems, pressure relief requirements, human safety, and emergency stop and manual activation functions are evaluated.

Fire Detection and Control in CO₂ Fire Extinguishing Systems

The CO₂ fire extinguishing system works integrated with the fire detection and control system. When appropriate fire detection devices placed in the protected area detect a fire, they send a signal to the control panel. According to the system scenario, alarms and warnings are activated, and after the necessary safety procedures are completed, the CO₂ discharge process is carried out. Through this structure, the aim is not only to extinguish the fire but also to ensure that the system operates in a controlled and safe manner.

Monitoring Gas Quantities in CO₂ Cylinder and Tank Systems

Regularly checking the amount of extinguishant stored in CO₂ extinguishing systems is important for system reliability. Depending on the design of the system, the status of the cylinders or tanks can be tracked using suitable weighing systems, pressure gauges, and control methods recommended by the manufacturer. During periodic inspections, the physical condition of the cylinders, valve groups, piping, nozzles, detection equipment, control panel, and other components of the system must also be checked.

Standards in CO₂ Fire Extinguishing Systems

In the design and application of carbon dioxide fire extinguishing systems, relevant national and international standards must be taken into account according to the scope of the project and the equipment used. NFPA 12 is an especially important reference standard for CO₂ systems. Depending on the nature of the project, BS 5306, VdS, and other relevant technical specifications can also be evaluated. When designing the system, one should not act solely based on the name of a single standard; the risk to be protected, facility characteristics, local legislation, project specifications, and the manufacturer requirements of the equipment used must be evaluated together.

Installation and Commissioning in CO₂ Fire Extinguishing Systems

In order for a professional CO₂ fire extinguishing system to operate reliably, the installation must be carried out in accordance with the project and manufacturer technical documents. Within the scope of the installation, the setup of CO₂ cylinders or tanks, assembly of valve and manifold groups, installation of the piping system, placement of extinguishing nozzles, assembly of fire detection equipment, control panel connections, alarm and warning systems, manual activation and emergency stop equipment, and necessary auxiliary system integrations are applied. After the installation is complete, functional tests of the system are performed, and commissioning procedures are carried out according to the project requirements.

Periodic Maintenance of CO₂ Fire Extinguishing Systems

Regular maintenance and checks must be performed to keep gas fire extinguishing systems constantly ready. Within the scope of periodic maintenance, the mechanical and electrical components of the system, CO₂ storage equipment, valve groups, piping, nozzles, detection system, control panel, and alarm functions are checked. Resolving any deficiencies identified during maintenance is of critical importance for the system to intervene in a fire when necessary.

AYSO Teknik CO₂ Fire Extinguishing Solutions

As AYSO Teknik, we offer professional solutions in carbon dioxide gas fire extinguishing systems regarding risk analysis, engineering design, system selection, projecting, material supply, installation, commissioning, testing, and periodic maintenance processes. We develop applicable CO₂ fire extinguishing solutions for different risk groups ranging from energy facilities to industrial production plants, from generator and transformer rooms to petrochemical facilities. For each project, the appropriate system solution is determined by evaluating the characteristics of the protected area, fire risk, equipment structure, and operating conditions.

Frequently Asked Questions

How many cylinders are used in a CO₂ fire extinguishing system?
The number of CO₂ cylinders to be used is determined according to the volume of the protected area, fire risk, required extinguishing concentration, and system design calculations. While single or a few cylinders may be used in small applications, multiple cylinder groups or low-pressure tank systems may be preferred in large industrial facilities.
How is the fill level of CO₂ cylinders monitored?
The status of CO₂ storage equipment is monitored with appropriate control and tracking methods depending on the structure of the system. Especially in high-pressure cylinders, weight control, and examination of cylinder connections and valve groups are important for system reliability.
When can the room be used after the CO₂ extinguishing system discharges?
After the system discharges, the protected area must be made safe. The area should only be entered after the CO₂ has been removed from the environment, necessary ventilation has been provided, and it has been verified that the atmosphere is safe.
Why is the ventilation system important in CO₂ systems?
After the discharge of CO₂, it may be necessary to remove the gas in a controlled manner. Therefore, the existing ventilation system, exhaust arrangement, and possible gas evacuation scenario of the protected space must be evaluated during the design phase.
How is nozzle placement determined in a CO₂ fire extinguishing system?
Nozzle placement is determined according to the geometry of the protected area, ceiling height, positions of the equipment, piping structure, and the features of the nozzle used. An appropriate distribution of nozzles must be ensured in line with engineering calculations.
How are pipe diameters determined in CO₂ systems?
Pipe diameters are calculated by considering the amount of CO₂ to be used in the system, discharge time, piping lengths, elbows and connection fittings, and nozzle requirements.
Can a CO₂ fire extinguishing system be connected to the existing fire alarm system?
Yes. CO₂ extinguishing systems can be designed to work integrated with fire detection and alarm systems. The control of fire detection, alarm, pre-warning, delay, discharge, and necessary auxiliary equipment can be managed within a single scenario.
Can a manual discharge feature be used with the CO₂ system?
Depending on the system's design and application standard, manual activation equipment can be used. The manual activation mechanism should be positioned to allow authorized personnel to activate the system in a controlled manner.
How to prevent accidental discharges in a CO₂ fire extinguishing system?
To prevent accidental discharges, fire detection scenarios, cross-zoning logic, time delays, manual control, and other safety functions can be applied according to project requirements.
Do changes need to be made to the room when installing a CO₂ system?
In some projects, yes. Especially in areas with total flooding, the status of doors, windows, ventilation openings, cable penetrations, and other openings can affect system performance.
Where are CO₂ systems refilled?
CO₂ cylinders that are empty or need to be refilled due to maintenance should be refilled by authorized organizations with the appropriate filling infrastructure and technical competence.
Can a CO₂ fire extinguishing system be used together with another extinguishing system?
Yes. Depending on the fire risk of the project and the equipment to be protected, the CO₂ system can be evaluated together with fire detection, sprinkler, water mist, foam extinguishing, or other fire safety systems.
In which projects should CO₂ systems not be preferred?
Due to the risks CO₂ poses to human safety, it may not be an appropriate solution in normally occupied areas or areas where safe evacuation cannot be ensured. Additionally, not every fire risk is suitable to be extinguished with CO₂.
What should be considered when choosing a CO₂ fire extinguishing system for a new facility?
In system selection, fire risk, process characteristics, combustible materials, equipment value, the occupancy status of the space, extinguishing method, discharge time, storage capacity, piping, and nozzle placement along with relevant standards must be evaluated together.
Can an existing CO₂ fire extinguishing system be redesigned?
A re-evaluation can be made by examining the existing system's cylinder capacity, piping structure, nozzles, valve groups, detection system, and the current condition of the protected area. Changes made to machinery, equipment, or space in the facility may necessitate the recalculation of the existing system.