Carbon Dioxide(CO2)
Fire Suppression System

A Carbon Dioxide (CO2) fire suppression system is a fixed automatic gaseous suppression system that discharges CO2 — a naturally occurring, electrically non-conductive, residue-free gas — into a protected enclosure or directly onto a localized hazard to extinguish fire rapidly and completely.

CO2 extinguishes fire through two simultaneous mechanisms:

• Oxygen displacement — CO2 is 1.5 times heavier than air. When discharged, it rapidly displaces oxygen in the protected space, reducing the oxygen concentration below the level required to sustain combustion (typically below 15% for most flammable materials, compared to 20.9% in normal air)
• Heat absorption — CO2 discharges at very low temperatures and absorbs significant heat energy from the fire as it vaporizes, actively cooling the combustion zone

Because CO2 is a natural component of the atmosphere and leaves absolutely no residue after discharge, protected equipment and surfaces require no cleanup or decontamination after system activation — a significant operational and cost advantage over powder-based or foam suppression alternatives.

Critical safety note: CO2 at fire-suppression concentrations is hazardous and potentially fatal to humans. CO2 systems are designed for areas that are normally unoccupied, or where positive confirmation of evacuation before discharge can be reliably achieved. For areas with regular human occupancy, clean agent systems such as FM-200 or Novec 1230 are the appropriate alternative.

Total Flooding

In total flooding applications, CO2 is discharged into a fully enclosed space — a room, cabinet, or sealed enclosure — flooding the entire volume to achieve and maintain a uniform suppression concentration throughout. Total flooding is used when the hazard occupies or could spread to fill the entire protected space.

Design concentration: Typically 34% CO2 by volume for Class B and C hazards in total flooding applications, or higher for specific materials. The system must maintain this concentration for the required hold time (per NFPA 12, a minimum 20-minute soak period for surface fires) to prevent re-ignition.

Typical total flooding applications:

• Electrical switchgear rooms and cable spreading rooms
• Diesel generator rooms
• Transformer vaults
• Ship engine rooms and machinery spaces
• Printing machinery enclosures
• Dust collector and filter housings
• Silos and process enclosures

Local Application

In local application, CO2 nozzles are positioned to discharge directly onto a specific piece of equipment or a defined surface hazard — without requiring the surrounding area to be enclosed. The agent is applied at a high rate directly to the flame front and the surface from which fire is being generated.

Design approach: Nozzles are engineered to achieve the required application rate over the full surface area of the hazard within the specified discharge time, maintaining agent concentration at the surface despite the absence of enclosure containment.

Typical local application uses:

• Aluminum rolling mills and metal processing equipment
• Hydraulic systems and oil-lubricated machinery
• Dip tanks and quench tanks
• Paint and powder coating booths
• Printing press ink systems
• Conveyor belts and dryers
• Open turbine enclosures and bearing assemblies

• CO2 Storage Cylinders — High-pressure cylinders containing liquefied CO2 under pressure, sized to provide the design quantity required for the protected hazard. Available in standard 45 kg cylinders; multiple cylinders manifolded together for larger systems
• Cylinder Valve & Solenoid Actuator — Controls agent release; the solenoid actuator opens the cylinder valve automatically upon signal from the control panel, or manually via the mechanical pull station
• Distribution Piping & Nozzles — Engineered pipe network delivering CO2 from the cylinder bank to the discharge nozzles at the calculated flow rate and pressure; nozzle type and placement determined by application method (total flooding or local application)
• CO2 Control Panel — The system brain; receives signals from fire detectors, manages the pre-discharge sequence (alarm, time delay, abort function), and triggers agent release. Provides automatic and manual operation modes
• Fire Detection Devices — Smoke detectors, heat detectors, or flame detectors (cross-zoned for reliability) monitoring the protected space continuously
• Pre-Discharge Warning Devices — Audible alarms (alarm bells or multi-tone sounders at 94 dB+) and visual indicators (strobe lights, gas discharge indicator lamps) providing mandatory warning before agent release
• Manual Pull Station — Allows manual system activation in the event of detector failure or for emergency use by trained personnel
• Abort Station — Allows authorized personnel to halt the discharge sequence during the pre-discharge countdown if the alarm is false; critical safety device in areas with any personnel access
• Pressure Switch & Low-Pressure Alarm — Monitors cylinder pressure continuously; alerts maintenance team if agent quantity falls below minimum level due to leakage
• Door Releases & HVAC Shutdown — Automatically closes fire doors and shuts down HVAC systems serving the protected space on alarm activation, preventing agent loss through air handling openings

1. Detection — Single Zone (Pre-Alarm) — The first fire detector activating triggers a pre-alarm: audible alarms sound inside the protected space, warning any personnel to evacuate immediately
2. Detection — Cross-Zone (Suppression Sequence) — A second detector in the cross-zone activates, confirming a genuine fire event and initiating the suppression sequence
3. Pre-Discharge Countdown — The control panel begins a programmable time delay (typically 30 seconds) allowing complete evacuation. Visual gas discharge indicator lamps illuminate. The abort station can halt the sequence if needed
4. HVAC Shutdown & Door Closure — HVAC systems are de-energized and fire-rated dampers close automatically, sealing the protected space to prevent CO2 loss
5. Agent Discharge — The solenoid actuator opens the cylinder valve(s). CO2 flows through the distribution piping and discharges through the nozzles into the protected space at high velocity
6. Suppression — CO2 rapidly fills the space, displacing oxygen and absorbing heat. Fire suppression occurs as the oxygen concentration drops below the combustion threshold — typically within 60 seconds of discharge initiation
7. Hold Period (Soak Time) — Per NFPA 12, the CO2 concentration must be maintained for the required soak time — a minimum of 20 minutes for surface fires and longer for deep-seated fires — to ensure complete extinguishment and prevent re-ignition
8. Post-Discharge Ventilation — After fire suppression is confirmed by qualified personnel, the space is ventilated to remove CO2 before re-entry. The system is inspected, cylinders are recharged, and the system is reset to automatic standby

1. Hazard Assessment — We classify the protected hazard (Class B, C, or A deep-seated), determine the application method (total flooding or local application), and assess enclosure integrity for total flooding applications
2. CO2 Quantity Calculation — Full NFPA 12-compliant agent quantity calculation based on enclosure volume, design concentration, temperature correction factors, and leakage compensation
3. System Design — Cylinder bank sizing, piping network design, nozzle selection and placement, control panel specification, detection layout, and safety device placement
4. Equipment Procurement — CO2 cylinders, valves, actuators, distribution piping, nozzles, control panel, detection devices, alarm devices, abort stations, and door releases from certified manufacturers
5. Installation — Cylinder rack installation, piping and nozzle installation, control panel wiring, detection device installation, HVAC shutdown interface, door release installation, and safety signage
6. Commissioning & Functional Testing — Full system functional test including detector activation, pre-discharge sequence verification, abort function test, HVAC shutdown confirmation, and door closure test — all without discharging CO2 agent
7. Personnel Training — Training for facility personnel on system operation, warning signal recognition, evacuation procedures, abort station use, and post-discharge re-entry protocols
8. Ongoing Maintenance — Annual inspection per NFPA 12 including cylinder weight verification, valve and actuator inspection, detector testing, piping and nozzle inspection, and low-pressure alarm test

For post-commissioning system care, visit our Service & Maintenance page.

CO2 is one of four gaseous suppression agents offered by PT Totalfire Indonesia. For occupied spaces or applications with different requirements, explore our other options:

• • FM-200 (HFC227ea) System — Fast-acting clean agent safe for occupied spaces; the standard choice for server rooms, data centers, and control rooms
  • Novec 1230 System — Next-generation clean agent with near-zero GWP; safe for occupied spaces and the most environmentally sustainable option
  • Inert Gas System — Naturally occurring gas blend with zero GWP; safe for brief human exposure and ideal for archives, museums, and heritage facilities

• Sprinkler System — Automatic water-based suppression for the broader facility surrounding CO2-protected enclosures
• Water Spray System — Fixed directional water spray for transformer cooling and industrial equipment protection
• Fire Hydrant System — Manual large-scale suppression for the overall facility
• Foam System — For flammable liquid hazards outside CO2-protected enclosures