CAFS Compressed Air Foam Systems
What is CAFS?
CAFS stands for Compressed Air Foam System.
It is a fire suppression technology that combines water, a selected foam concentrate and compressed air to create an aerated firefighting foam.
Unlike conventional systems that simply discharge water or water mixed with foam concentrate, a CAF creates the foam before it reaches the discharge nozzle.
This produces a consistent, aerated suppression medium that can be delivered through fixed pipework, hoses or specialised nozzles.
The result is a firefighting medium designed to provide rapid flame knockdown, improved surface coverage and sustained cooling, while making more efficient use of the available water.
RML AU CAFS generators are factory calibrated and tested before delivery to provide consistent foam production for the intended application.
How does CAFS work?
The basic principle is straightforward:
Water + selected foam agent + compressed air = compressed air foam.
Inside the RML AU foam generator, water and the selected foam concentrate are mixed with compressed air. This creates a uniform foam that is then transported through the system to the discharge point.
The compressed air creates millions of small bubbles within the foam. These bubbles help the water remain on the surface being protected rather than immediately running away.
This provides several important firefighting benefits:
rapid coverage of the burning surface
flame knockdown
sustained cooling
improved contact time between the suppression medium and the hot surface
reduced runoff compared with large-volume water application
the ability to deliver foam over long pipe runs and to elevated or difficult locations
RML AU systems automatically regulate foam generation according to the selected discharge outlet, helping maintain consistent foam quality even where outlets are changed during operation.
CAFS vs conventional water suppression
Water remains one of the most important and widely used firefighting agents in the world. CAFS does not replace water; it uses water differently.
A conventional water system generally relies on applying a significant volume of water to absorb heat and control the fire.
CAFS introduces compressed air and an appropriate foam agent into that water. This produces an aerated foam that can remain in contact with the hazard for longer and spread across surfaces rather than immediately draining away.
This means that, for suitable applications, CAFS can potentially achieve the required fire suppression performance using considerably less water.
There is no single fire suppression technology that is ideal for every fire risk. The correct system depends on the fuel involved, the size and location of the hazard, the available water supply, environmental requirements and the fire protection objectives.
RML AU therefore engineers the CAFS system around the specific risk rather than applying one standard solution to every site.
CAFS fire suppression system Australia exists with us using compressed air foam system Australia.
Where is CAFS used?
CAFS can be used across a wide range of industrial and high-risk environments.
Typical RML AU applications include:
Waste and recycling
Waste transfer stations, recycling facilities, material recovery facilities and battery-handling areas can contain large quantities of combustible material and may also receive lithium-ion batteries hidden within general waste streams.
CAFS can be installed to protect high-risk areas such as processing equipment, conveyors, stockpiles, bunkers and storage areas.
Lithium-ion batteries
Lithium-ion battery incidents present a particular challenge because a damaged or overheating cell can enter thermal runaway, where heat generated inside the battery can cause neighbouring cells to become involved.
In these applications, suppression is not only about extinguishing visible flames.
An effective response also needs to provide substantial and sustained cooling to help control heat and reduce the potential for thermal runaway to propagate to adjacent cells or battery modules.
CAFS can provide flame suppression together with prolonged cooling and surface coverage.
Mining
The growing use of battery electric vehicles and battery-powered equipment in mining creates new fire protection challenges, particularly underground.
Confined spaces, limited access and the potential generation of heat, smoke and hazardous gases mean that fire suppression systems may need to operate without placing personnel close to the incident.
CAFS can be incorporated into fixed suppression areas, vehicle protection strategies and dedicated fire suppression chambers.
Dangerous goods and industrial facilities
Facilities storing fuels, chemicals and other combustible materials may require rapid fire control and wide surface coverage.
CAFS can be engineered around bunds, loading areas, storage locations, processing equipment and other identified fire-risk zones.
Manufacturing and processing
Production facilities can contain machinery, lubricants, plastics, packaging and other combustible materials.
Fixed CAFS can be designed to protect individual assets or larger production areas.
Mobile firefighting
CAFS can also be installed on trailers, vehicles, skid-mounted units and other mobile platforms, allowing a high-performance foam system to be taken directly to the incident.
Fixed CAFS systems
A fixed CAFS system is permanently installed to protect a specific asset, process or area.
The system can be designed to protect anything from a single item of equipment through to a much larger industrial zone.
Fixed systems are particularly valuable where rapid automatic suppression is required or where it would be dangerous or impractical for personnel to approach a fire.
RML AU systems use factory-calibrated foam generation equipment with PLC-based control and can be configured for one-button operation and integration with site control or detection systems.
Mobile CAFS systems
A mobile CAFS system provides the same fundamental foam generation technology in a transportable format.
Mobile systems provide flexibility where a fixed installation is not practical or where one system is required to protect multiple areas.
They can also be used to supplement a site's fixed fire protection infrastructure.
Because compressed air foam can make efficient use of available water, mobile systems can be particularly valuable in locations where water supply is limited or needs to be transported to the fire.
How much water does CAFS use?
Water consumption is one of the major advantages of an appropriately designed CAFS installation.
RML AU's current system data shows water savings of up to 85% compared with traditional systems for the applications on which that figure is based.
The RML AU foam generator specification also identifies foam-agent consumption of approximately 3 litres per 1,000 litres of water compared with the benchmark figure of 10 litres per 1,000 liters of water.
This lower water demand can have benefits beyond the fire itself.
It may reduce requirements associated with:
water storage tanks
pumps
pipework
water supply infrastructure
containment
drainage
contaminated firewater management
site restoration following an incident
The actual water requirement for any project depends on the hazard, system design, discharge rate and required operating duration.
For this reason, RML AU assesses each application individually rather than applying a single water-saving figure to every installation.
Why is lower water consumption important?
Using less water can significantly change the economics and practicality of a fire suppression system.
On industrial, mining and remote sites, providing sufficient firefighting water can require large storage tanks, high-capacity pumps and substantial pipe infrastructure.
Underground, inside buildings or in remote environments, providing this infrastructure can be particularly difficult.
Lower water consumption can also mean less firewater runoff following activation.
This can be important where the water may become contaminated by fuels, chemicals, battery materials, waste or other hazardous substances.
Reducing the amount of water required does not remove the need for appropriate containment or environmental planning, but it can reduce the volume that needs to be managed.
Lithium-ion battery applications
Lithium-ion batteries require a different way of thinking about fire protection.
With many conventional fires, extinguishing the visible flames is the primary objective.
A lithium-ion battery can continue producing significant heat internally even after the external flames have been controlled.
This process can cause neighbouring cells to heat up and enter thermal runaway.
For this reason, lithium-ion battery fire protection generally needs to address two things:
1. Flaming combustion
The visible fire needs to be rapidly controlled.
2. Heat and thermal runaway propagation
The battery and surrounding cells need sustained cooling to reduce the likelihood of the event spreading.
CAFS is particularly relevant to this type of risk because it combines flame suppression with sustained surface cooling.
RML AU develops CAFS solutions for lithium-ion battery applications including:
battery energy storage systems
battery storage and charging areas
electric vehicles
underground mining BEVs
waste and recycling facilities
battery recycling
industrial battery installations
mobile and fixed battery fire protection systems
The specific system configuration depends on the battery type, battery size, enclosure, surrounding materials and the consequences of a fire at that location.
RML AU therefore focuses on controlling the fire, cooling the battery and limiting thermal runaway propagation, rather than suggesting that every lithium-ion battery event can be treated in exactly the same way.
What foam agents are used?
The foam concentrate must be appropriate for the fire risk and the environment in which the system will operate.
RML AU systems can use selected foam concentrates according to the application.
The company's current CAFS system uses fluorine-free, biodegradable foam chemistry, designed to reduce environmental impact compared with older generations of fluorinated firefighting foams.
Selection of the correct foam agent is an important part of the overall system design.
Is CAFS only about foam?
No.
The foam itself is only one part of an effective fire suppression system.
A properly engineered installation also considers:
how the fire will be detected
how quickly the system will activate
where the foam needs to be delivered
how much foam is required
how long cooling needs to continue
the available water and air supply
the fire load
the geometry of the protected area
environmental containment
integration with the site's existing fire and safety systems
The objective is not simply to produce foam.
It is to deliver the right suppression medium, at the right location, at the required rate and for the required duration.
Testing and evidence
Fire suppression performance should be supported by evidence.
RML AU uses testing to understand how its systems perform under realistic fire conditions and to determine appropriate application rates, discharge arrangements and operating durations.
Depending on the application, this may include:
live fire testing
lithium-ion battery fire testing
flame knockdown observations
thermal imaging
temperature monitoring
water consumption measurement
foam application testing
cooling performance
system discharge testing
photographs and video
post-test examination
RML AU's CAFS generators are also factory calibrated and tested prior to delivery to help ensure that the equipment produces the required foam consistently.
Where available, RML AU publishes test videos, photographs and performance information so customers, engineers and fire professionals can see how the technology performs rather than relying solely on product claims.
A different way to think about fire suppression
CAFS is not simply about creating more foam.
It is about making better use of water and delivering a suppression medium that remains where it is needed for longer.
For high-risk environments—including lithium-ion batteries, waste and recycling, mining, industrial processing and dangerous goods—the ability to rapidly suppress flames while continuing to cool the hazard can provide an important additional level of protection.
RML AU engineers compressed air foam systems around the risk: from individual assets to mobile systems and complete site-wide fire suppression solutions.