CAFS Compressed Air Foam Systems are self contained stored-energy fire suppression units which have the added ability to inject compressed air into the foam solution to generate a powerful fire attacking and suppression foam. This type of foam has tighter and more dense bubble structure than pure water or standard foam solutions. This bubble structure allows the foam to adhere to vertical and horizontal surfaces as well as penetrate fires deeper before the bubbles are broken down, allowing the latent water to be more effective.
A Compressed Air Foam System uses a Class A foam concentrate, combined with water, and compressed air to form a fire extinguishing agent that is greater than the sum of its parts. The synergistic affect is a product with greatly reduced surface tension, compared to that of plain water, which enables the solution to penetrate burning fuels much faster and more efficiently.
Even though water is the best agent we have, there are undeniable truths as to its limitations and dangers in using water on the fireground. Where large volumes of water are required to effectively achieve knockdown, there is a potential danger of structural collapse due to the additional weight of the water.
This is one of the primary reasons we add detergent foams (which just happens to define the chemical composition of a Class A foam) into our laundry. It is the foam or “soap” that breaks down the surface tension and allows our water to penetrate. This is not only important in getting our clothes clean, but decidedly more efficient in using water on the fireground for suppression. Have you ever noticed how a drop of plain water just puddles on a piece of charred wood and doesn’t soak in? That’s because of the water’s surface tension. It’s a fact that the larger the fire, the larger the hose line becomes to handle the additional volume of water being discharged. This equates into heavier handlines which require additional manpower and are often much more difficult to maneuver. This also requires larger fire pumps, additional fuel usage, and often leads to increased fatigue of men and equipment. You get the idea.
There are undoubtedly veterans out there who are sure to echo “we’ve been doing it that way for years and it still works.” Consider this, “you can kill a polar bear with a stick, too, but it just might not be the best method.”