Pflugerville Fire Department

WELCOME TO THE PFD CAFS RESOURCE

Our department receives many requests from other fire departments for information regarding what we do with CAFS. We operate an all CAFS fleet and flow compressed air and foam on every fire.

While there is a wealth of information from manufacturers about CAFS, very little of it covers actual training and tactics using CAFS. Most of what we have learned was through trial and error.

Our training and experiences with CAFS is ongoing and continues to evolve. In no way do we claim to know it all or have all the answers to questions regarding CAFS. The information provided herein is based upon our experience and use of CAFS and make no claim other than it is what works for us. We believe that our experience and practices support the premise that CAFS defines the future of firefighting.

The Great Nozzle Debate

There is no debate that you get the best CAFS through a straight or smooth bore tip. However, orifice size may be a point of contention. We found through trial and error that a 15/16” opening allows for the best reach and foam quality. A 1-1/8” opening produces great foam, but the reach of the stream suffers greatly.

Another nozzle issue is the use of smooth bores on interior structural attacks. Some of this concern can be traced to the age old debate about using fog or smooth bore nozzles. Most fire fighters in our area are trained to conduct interior attacks with a fog tip.

We believe a more modern and perhaps liberal outlook on these nozzles. We find that they both work great but in different situations. Since 1996 we have used a 15/16” pistol grip nozzle with an attachable fog nozzle.

Many of our fire fighters fall back to their early training and find great comfort in the use of fog nozzles with the protection that a power cone affords while advancing a line in a heated environment. This mindset was carried over with the introduction of CAFS.

For several years we conducted interior and exterior fire attacks using CAFS and fog tips. We had great success with rapid knock down and reduced collateral property damage. However, to truly reap the total benefits of CAFS a smooth bore tip should be used.

We will demonstrate the use of smooth bore tips and CAFS on interior structure fires later in this presentation. The phenomenal effects support use of smooth bore nozzles even inside the structure; however, it is not our wish to diminish any safety aspect that a fire department imparts to its personnel.

The way you and your department view nozzles will have an effect on how it uses CAFS. The point to remember is that even by stripping some of the air from the CAF stream with a fog nozzle, the end result is still a more superior product to that of a plain water application and even better than a foam solution (just water and foam without the air).

CAFS and Fire Gasses

The subject of fire gasses has been a very hot topic in recent years. Fire gasses play a crucial role in fire intensity, spread, and progression to flashover. Thanks to Dave Dodson a lot of attention is being paid to fire gasses and the dangers they present. Dave Dodson is the author of an article and class called Smoke Reading (www.respondsafe.com)

Questions have been raised about CAFS’ ability to suppress these burning fire gasses. We believe these issues are related the fact that one of the reasons CAFS works so well is its ability to adhere and “stick” to fuels. If one focuses on this as the only reason CAFS works so well it is easy to understand the concerns. Since these fire gases are not solid and the foam has nothing to cling to, the debate is raised.

We have used CAFS on fire gasses both on the fire ground and in live fire training. We found that CAFS does in fact suppress fire gasses. This may be related to the theory that a CAFS bubble has a uniform 360 degree surface area to absorb BTUs. In contrast to a water droplet that is more subject to gravity and has a smaller surface area.

Live Fire Training

We recently conducted live fire training using CAFS and recorded it. We placed our thermal imaging cameras and recorded temperature drops inside the burn rooms. This data was broadcast and recorded on a remote TV. While the environment and our equipment are less than scientific an obvious and instant temperature reduction was witnessed and recorded on every fire with the use of CAFS.

A very short burst of CAFS through a smoothbore and fog tip was applied to the gasses burning overhead. The result was an almost immediate reduction of temperature; from 800 degrees Fahrenheit to less than 300 degrees Fahrenheit (these temperatures were captured with our thermal imaging camera). While we did not have thermo couplers measuring the fire gasses we were able to see, with the naked eye, immediate extinguishment in the overhead.

Thermal video

To more closely demonstrate realistic fire situations, we used a fuel cell constructed of two layers of ½-inch sheetrock. Two couches, a chair, and a TV stand were placed in the 8’ X 20’ enclosed cell.

Once the fire was in a free burning state and fire gasses were pushing out the door a very short burst of CAFS (2:1 solution) was introduced into the fire overhead. The fire was extinguished almost immediately.