The science behind fire suppression--and a pitch for home fire sprinklers

Blog Post created by freddurso Employee on Aug 26, 2015


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Have you heard? The fire service has started embracing a series of scientific experiments that’s producing quantifiable data to help determine how to best fight fires. This scientific approach is said to be altering fire suppression tactics used by firefighters. Fire service journals, websites, and conferences are all highlighting this fire-attack-based-on-science phenomenon. And suppression people (like me) are absorbing, debating, and applying the latest information.

I support the scientific approach to studying fire dynamics and fire attack. I truly applaud the work of the good people at UL, NIST, NFPA, and other organizations for their efforts to publicize and promote their findings. I truly believe this data will improve our understanding of fire dynamics in the modern built environment and lead to changes in the way many approach fire. And, I truly believe this will lead to reduced line-of-duty firefighter injuries and deaths.

However, the science really isn’t all that new, and the application of the science really isn’t so complex. Also, the resulting perspective towards a “revolutionary change” in fire suppression is actually a little short-sighted. Again, these statements are not meant to critique the people doing the research, or the research. They are great people who are more intelligent than me. But, let me explain my claims and challenge you to dig a little deeper.


First, fire does not burn any differently now than before. It is, in fact, a science. It can be, and has been, replicated in various laboratories for decades. Its behavior can be predicted and controlled by changing certain variables affecting the combustion process, such as various aspects of the fuel load or oxygen supply. As an example, in the early 1950s, Keith Royer and Floyd Nelson published their research in the Iowa State Training Bulletin, Water for Fire Fighting. In it, they stated,  

+“The Firefighter is more interested in the amount of heat that is being produced when the attack is made and the fact that the oxygen supply to a fire does more to set limits on heat production than the amount of fuel available. +Of more specific interest to the firefighter rather than the total fuel load is the rate at which heat energy is being released during the actual fire.”


Sound familiar? Since its discovery, fire has been an exothermic chemical reaction emitting heat and light. I must agree that our understanding of fire behavior through scientific research has improved greatly over the decades, especially in recent years, and this research needs to continue. Also, the built environment in which fires are occurring +has changed significantly+ in recent decades, which has impacted the fire dynamics we are facing today.

Moreover, scientists have always been very smart people, and they now have even cooler toys than ever before. They can breakdown, verify, validate, and explain the aspects of both the combustion process and the suppression process with remarkable detail. They can now show data in the form of colored graphics, computerized models and simulations, and videos that can grab a firefighter’s attention. It’s important for all of us to understand that the science behind the combustion process is complex. Though not a scientist, I believe the science can be simplified and summarized when applied to the suppression process without compromising results:


Fire releases heat. Water absorbs heat. All other variables being equal, the bigger the fire, the more heat released. The more heat released, the more water required to absorb the heat. When the application rate of the water exceeds the heat-release rate of the fire, the fire goes out.

While I encourage all to study, learn, and understand the science of fire dynamics in the modern built environment, this basic concept sums it up.

Another thought: Suppression people are scrambling to “reinvent” fire attack methods based on new research. One account I read said that science is going to “revolutionize” the way we fight fires. I must say, I find this rather humorous. Many insightful fire officers have understood and applied certain firefighting principles for decades. Their first priority on the fireground has always been to aggressively achieve a rapid knockdown with tank water, often through a window or door for 30 seconds or so. Science has not discovered this tactic, nor are scientists claiming to have done so. They are, however, now proving its effectiveness through their research.

The “new science” is a big change for many, a real paradigm shift, as they like to say. I understand that we will be faced with attacking fires in non-sprinklered buildings and dwellings for decades to come, so we need to be talking about how best to do that. But, I must say we are falling short when applying scientific research to fire suppression. Science is “proving” that fire releases heat and that water absorbs heat. Yet, we only seem to be focusing on changing the fire suppression process by improving how we apply big water to big fires. We are claiming to do this in the interest of more effective, efficient, and safer firefighting techniques, which I agree is an important concept.


Why aren’t we also focusing on changing the fire suppression process in the future by simply applying a little water to a little fire before it gets big? Would this not be a more effective, efficient, and safer means of firefighting? Science has proven the unmatched, suppression capabilities of fire sprinklers.Why aren’t we giving sprinklers as much attention as we are the other revolutionary tactics we claim to have just discovered? It is time that suppression people start viewing – no, embracing – home fire sprinklers as an improved “revolutionary” tactic for the future of firefighting.


This post was written by Rick Ennis, fire chief for the City of Cape Girardeau in Missouri and chair of the Missouri Fire Sprinkler Coalition.

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