What are the differences between dry powder fire extinguishers and CO2 fire extinguishers in terms of effectiveness and scope of application

Fire extinguishing mechanism and advantages of dry powder fire extinguisher
Dry powder fire extinguisher is a device that extinguishes fire by spraying dry powder fire extinguishing agent. Its working principle is to use compressed gas to spray dry powder, which covers the surface of the burning object, cuts off oxygen, and extinguishes the fire by interrupting the combustion chain reaction.
Common types of dry powder include ABC dry powder and BC dry powder. ABC dry powder is suitable for Class A (solid), Class B (liquid), and Class C (gas) fires; BC dry powder is mainly used to extinguish Class B and Class C fires. Dry powder has the characteristics of strong broad spectrum, rapid fire extinguishing, and strong fire extinguishing ability.

Fire extinguishing principle and characteristics of CO₂ fire extinguisher
Carbon dioxide fire extinguisher (CO₂ fire extinguisher) sprays high-pressure carbon dioxide gas to the fire source, quickly reducing the oxygen concentration around the fire source, and achieving the purpose of suffocation fire extinguishing. At the same time, the rapid expansion of CO₂ gas during injection absorbs a lot of heat, plays a cooling role, and thus assists in fire extinguishing.
CO₂ fire extinguishers are suitable for Class B and Class C fires, and are particularly suitable for extinguishing fires in places such as live equipment, precision instruments, data centers, and laboratories, because they do not leave any fire extinguishing residues and will not cause secondary damage to electronic equipment.

Comparison of usage effects
Dry powder fire extinguishers have a fast fire extinguishing speed and have a good inhibitory effect on most combustible materials. They are particularly efficient in extinguishing initial fires. However, a large amount of powder will remain after the dry powder is sprayed, which may cause pollution and corrosion to mechanical equipment and electronic components, and impose a heavy burden on subsequent cleanup.
CO₂ fire extinguishers are ideal for extinguishing fires in precision equipment areas, and will not leave fire extinguishing residues. However, their fire extinguishing ability is limited in open spaces because carbon dioxide is easy to diffuse quickly, and once the air circulation is strong, the fire extinguishing effect will be significantly reduced. In addition, CO₂ fire extinguishers do not have effective extinguishing capabilities for combustible solids (Class A fires).

Scope of application analysis
Dry powder fire extinguishers are suitable for the following environments and scenarios:
Industrial plants, storage and logistics centers;
Transportation vehicles such as cars and ships;
Combustible storage areas in buildings;
Comprehensive places that require broad-spectrum fire extinguishing capabilities.

CO₂ fire extinguishers are suitable for the following professional scenarios:
Data centers, server rooms;
Medical equipment rooms, precision electronic laboratories;
Power distribution rooms, high-voltage electrical control cabinets;
Food processing workshops and areas with high cleanliness requirements.

Safety and precautions for use
Dry powder fire extinguishers are simple to operate and suitable for most non-professionals. When using, be sure to stand upwind to prevent dry powder from backblowing into the respiratory tract. Dry powder is relatively less irritating to personnel, but long-term inhalation of dry powder aerosols should still be avoided.
There is a risk of suffocation in the spraying area of the CO₂ fire extinguisher, especially when used in a confined space, it is necessary to ensure that the operator evacuates quickly. Carbon dioxide has the risk of frostbite due to low temperatures, and the area near the nozzle must not be in direct contact with the skin to avoid frostbite accidents.

Maintenance and life differences
Dry powder fire extinguishers need to be regularly checked for pressure, dry powder status and nozzle patency. Long-term non-use can easily lead to dry powder agglomeration, so it should be shaken and checked regularly. It is recommended to refill or replace dry powder every 5 years.
CO₂ fire extinguishers have a relatively closed structure and low maintenance frequency. It is necessary to regularly test the bottle pressure and weigh to check gas loss. Its service life is usually longer, but it needs to be regularly tested for air tightness according to national standards.