NIST’s Fire Calorimetry Database Is Available to Answer Your Burning Questions

Fire protection system design and regulation of flammable materials can be improved with accurate knowledge of fire growth

Published: Tuesday, January 19, 2021 - 13:03

Burning plastic cart carrying a fax machine, a laptop computer, and a three-ring binder. Click here for larger image. Credit: FCD/NIST

Several centuries ago, scientists discovered oxygen while experimenting with combustion and flames. One scientist called it “fire air.” Today, at the National Institute of Standards and Technology (NIST), we continue to measure oxygen to study the behavior of fires.

The NIST National Fire Research Laboratory (NFRL) has four progressively larger canopy hoods that are used to research the behavior of fires. The hoods, like massive lungs, suck in fresh air to give life to the fire under our watchful eyes. We carefully document these unique experiments using multiple cameras and up to several hundred measurement sensors. The hoods’ exhaust enters a series of long metal ducts where the gases and particles are carefully measured before they are scrubbed clean and returned to the outside.

The size of a fire, quantified as the heat release rate, is measured in watts. There are many ways to determine fire size, but one versatile and accurate method, pioneered at NIST in the 1970s, is to capture all the smoke from a fire and measure the amount of oxygen the fire consumes. This method is based on the observation that, for a wide range of combustible materials, the thermal energy produced by a fire is proportional to the mass of oxygen it consumes. The “oxygen consumption calorimetry” test method is now widely adopted as a tool for studying fires and developing materials with improved fire performance. In the NFRL, we can make measurements of fires up to 20 million watts in size, enough to study fire growth in multistory buildings.

Supercut of video footage from the Fire Calorimetry Database (FCD). The Fire Calorimetry Database contains tabulated summary data and downloadable video footage with overlaid heat release rate and supplemental data from fire experiments conducted at the National Fire Research Laboratory. Search the FCD at www.nist.gov/el/fcd.

Flashover in a mock-up of a furnished kitchen. The fire was started by autoignition of a pan of cooking oil left unattended on the stove. Click here for larger image. Credit: FCD/NIST

Measuring the size and growth rate of a fire is important for many reasons. Fire protection system design and regulation of flammable materials hazards can be improved with accurate knowledge of fire growth in specific scenarios. Computer simulations of fires often need fire growth rates as input, and fire model developers rely on accurate fire measurements for validation. These models are used for the design of fire safety systems such as sprinklers or smoke control fans, and in some cases the design of building structural systems. Fire models have also been used in forensic studies to investigate the cause and timeline of a fire.

Table of fire calorimetry data from a fire started in a mock-up of a furnished kitchen. Click here for larger image. Credit: FCD/NIST

I am proud and excited about the recent release of the Fire Calorimetry Database (FCD). This living database of real-scale fire experiments provides the public with free and open access to fire calorimetry results. The FCD contains experiments ranging in scale from small single items to fully furnished rooms. Each experiment contains detailed documentation about methodology and uncertainty. In addition to the fire heat release rate, we provide other fire properties such as the generation of soot particles and carbon monoxide gas. Users of the FCD can view experiments in a time-compressed high-resolution video augmented with data and time stamps.

Plot of carbon monoxide produced by a fire in a mock-up of a furnished kitchen: (1 ignition; 2) 360 camera started; 3) smoke alarm activation; 4) pan oil ignition; 5) flashover; 6) oriented strand board (OSB) in wall burning; 7) external OSB ignition visible; 8) OSB wall collapse; 9) further wall collapse; 10) start fire suppression; and 11) fire out. Click here for larger image. Credit: FCD/NIST

Transition of these complex datasets from internal research resources into a tool for wider public use required a team effort. Over the past several months, a core team of NFRL staff has collaborated with colleagues in NIST’s Office of Information Systems Management to build the software infrastructure to share these data over the NIST website. The interaction between fire researchers and information technologists was fun and rewarding, pushing us all to clearly communicate outside of our normal areas of expertise.

I started my career at NIST in the late 1990s and wrote basic computer code to analyze experimental results from bench-scale fire experiments. Over my career I have been involved with increasingly larger and more challenging experiments and have continued to develop computer code to analyze experimental results. The development of the FCD has been personally rewarding since it reflects this journey.

We hope this media-rich database will allow users to gain insight beyond what they may find reading a traditional publication. We anticipate that the FCD will be used by practicing engineers and researchers to better understand and control fires; however, I am curious what other audiences will find and use this resource. I would love to see examples in which data from the FCD are being used for education, training, or some other benefit to society.

About The Author

Matthew Bundy

Matthew Bundy is a mechanical engineer and leader of the NIST National Fire Research Laboratory (NFRL). Bundy received his Ph.D. from Washington State University in 1998. He has more than 20 years of experience conducting large scale fire experiments, and his research includes development of fire calorimetry methods, under-ventilated compartment fires, flammability measures for materials, and structural fire testing.