Gas Suppression System Design

A well-designed INERGEN (IG-541) gas suppression system reduces the amount of oxygen within a space to a point where a fire is suppressed. The design takes also takes into consideration that the area will be occupied by personnel when the agent discharges. Personnel can be evacuated safely as INERGEN poses no threat to their health.

INERGEN Fire Suppression Design Engineers, desktop

With years of experience successfully designing and specifying compliant gas fire suppression systems, Fire Systems Products are the perfect partner for your gas suppression projects. In addition, as being a leading fire systems and products supplier to the fire industry. We can provide impartial advice on the right gaseous fire suppression system design for your projects.

INERGEN System Design Criteria

Most fire gas system designs using INERGEN IG-541 are Total Flooding. Consisting of a fixed supply of agent connected to a piping system with nozzles to direct the agent into an enclosed hazard. Moreover, Inert gas extinguishes fires by lowering the oxygen content below the level that supports combustion. In short, if the atmosphere’s oxygen content drops to a level below 15%, most ordinary combustibles will not burn.

INERGEN IG-541 simultaneously reduces the oxygen concentration in an enclosure and increases the carbon dioxide concentration. Proper and safe system design requires that the agent design concentration falls within a design window limiting the upper and lower oxygen and carbon dioxide concentrations.

It is not permitted for changes to equipment, pipework, or nozzle positions to be made without the authority of the suppression system’s Design Engineer.

INERGEN IG-541 has a density similar to that of air and doesn’t decompose when subjected to heat from a fire, thus avoiding hazardous breakdown products. However, as a fire burns, it consumes oxygen and results in harmful gases and particulates such as carbon monoxide increasing in the atmosphere within the protected space. This may result in oxygen levels below the design threshold. For these reasons, the designer requires detailed information about the function of the room after completing the suppression system.


Under normal conditions, INERGEN system discharges do not reduce visibility in the protected enclosure. However, in a fire situation with large amounts of smoke, the agent discharge produces some displacement of that smoke around the enclosure, which reduces visibility in some circumstances.

Our Team

With 60+ years combined fire industry experience, our team provide proven gas suppression designs, and focused value-added engineering solutions. Furthermore, Fire Systems products has fostered strong relationships with leading manufacturers and industry partners, meaning that our system designers regularly receive the latest product information and training to enhance their level of expertise and the quality of our work.

In addition, the design team at Fire Systems Products can provide you with a site-specific INERGEN IG-541 design solution that supports the mitigation of safety risks. This process involves a consultation with our experts to evaluate the project’s requirements.

Furthermore, we have specified, designed, and commissioned high-quality INERGEN gas fire suppression system protection for many major institutions and commercial operations throughout Australia through our industry partners, complying with our duties as a designer under the Regulations.

Information Required for Gas Suppression System Design:

Limitations of INERGEN System Designs

When designing any Fire Suppression system, it is important to understand its limitations. Do not use INERGEN fire suppression systems to protect:

  1. Chemicals that contain their own supply of oxygen. For example, cellulose nitrate is used in gunpowder, nail polish and lacquer finishes.
  2. Mixtures containing oxidising chemicals. For example, sodium nitrate is used in fertilisers and explosives.
  3. Chemicals can undergo auto-thermal decomposition, where a chemical decomposes if it reaches a specific temperature.
  4. Reactive metals, e.g. the element’s sodium, potassium or magnesium.
  5. Areas where large surfaces are heated (not by fire) to a temperature that breaks down the chemical structure of the extinguishing agent. The agent is then unable to extinguish a fire.

For more information about INERGEN fire suppression system design.