Fire Investigation

Summary

The UL Firefighter Safety Research Institute investigates fire dynamics in full-scale structures to understand fire growth and spread. They study the effects of ventilation changes on fire patterns, using probes and sensors to measure temperature, gas velocity, and oxygen levels. This research aids firefighters in understanding fire behavior and assists investigators in determining fire origin and cause. The project aims to bridge the gap between suppression and investigation, enhancing overall fire service effectiveness.

Takeaways

• 🔥 Over the past decade, the UL Firefighter Safety Research Institute has been conducting research to better understand fire dynamics and improve firefighter safety.
• 🏠 The project focuses on how fires grow and spread in homes, especially how ventilation changes through doors or windows impact fire behavior and damage patterns.
• 🔄 Replicate fires are conducted with varying conditions, first with the structure closed and then with openings to observe how it affects fire growth and investigator findings.
• 📏 The research uses bidirectional probes to measure gas velocity and temperature, allowing scientists to track the movement of hot and cool air in and out of the building.
• 🌡️ Thermocouples are placed throughout the structure to measure temperature at different heights, giving insights into the hot gas layers and cooler air near the floor.
• 🧪 Oxygen concentration is monitored at various points to understand how the presence or absence of oxygen influences fire patterns and behavior.
• 📸 Detailed documentation of the house occurs before, during, and after the fire to help investigate the relationship between fire damage and the conditions that caused it.
• 💡 The project also focuses on observing how household items like lamps, phones, and TVs are affected by the fire, providing valuable insights for investigators.
• 🧩 The research aims to help both firefighters and investigators understand the impact of fire suppression tactics on fire patterns and investigation outcomes.
• 🎓 The project will result in an online training program, helping to bring these scientific findings to fire investigators around the world.

Q & A

What is the main focus of the research conducted by the UL Firefighter Safety Research Institute?

The research focuses on fire dynamics, particularly how fires grow and spread in homes, and how firefighters can operate safely and efficiently on the fireground.

How does the project benefit fire investigators?

The project helps fire investigators by studying burn patterns, fire damage, and how changes in ventilation (such as opening doors or windows) affect the investigation of a fire's area of origin and cause.

What is the significance of ventilation in the study?

Ventilation is a key variable in the study, as it impacts fire growth, burn patterns, and fire damage. The researchers aim to understand how ventilation affects fire behavior and investigation outcomes.

What tools are used to measure the fire's dynamics during the experiments?

The tools include bidirectional probes to measure gas velocity and temperature, thermocouples to monitor temperature at different heights, oxygen intakes to measure oxygen concentration, and pressure taps to measure high and low-pressure areas.

Why are energized outlets and devices included in the experiments?

Energized outlets, lamps, clocks, and televisions are included to observe how different objects react to fire, such as how they melt, fail, or come apart, providing insight into fire behavior and damage patterns.

What specific data is collected during the fire experiments?

Data collected includes temperature, gas velocity, oxygen concentration, pressure, and fire damage patterns, along with observations of object behavior during fire exposure.

How is the documentation process carried out during the experiments?

The house is documented with photographs before and after the fire, and additional documentation is done as furniture is removed and layers of the structure, such as flooring and subfloor, are revealed.

What happens during the 'sofa ignition' phase of the experiment?

The sofa is ignited, and researchers observe the temperature rise, oxygen levels, and fire behavior. They note when the fire starts to extinguish itself as oxygen levels drop and temperatures decrease.

Why is the project important to both firefighters and investigators?

The project enhances understanding of fire patterns for firefighters and helps investigators comprehend how suppression tactics and ventilation affect their ability to determine the fire's origin and cause.

What are the expected outcomes of the project for the fire service and investigation community?

The project aims to foster cross-discipline communication between firefighters and investigators, improve fire investigation techniques, and develop an online training program for fire investigators worldwide.

Outlines

00:00

🔥 Fire Dynamics and Ventilation Study

Over the past ten years, the UL Firefighter Safety Research Institute has been researching fire dynamics, focusing on how fires grow and spread in homes. This is vital for firefighters to operate safely and efficiently. The new project aims to apply this knowledge to fire investigations, studying the impact of ventilation on burn patterns by opening doors and windows during fires. Through controlled experiments in full-scale structures, researchers aim to understand how ventilation affects fire damage, growth, and the ability of investigators to determine the origin and cause of the fire. They will document the house before and after the fire, carefully analyzing the burn patterns on the walls, ceilings, and floors to establish cause-and-effect relationships. This research includes monitoring temperature, gas velocity, oxygen levels, and pressure throughout the structure to gain insights into fire behavior.

05:03

🧩 Piecing Together Fire Patterns

Fire patterns and effects, like fire damage and oxygen availability, are critical for understanding how a fire spread within a structure. The project aims to help both firefighters and investigators by demonstrating how ventilation and fire suppression tactics influence fire patterns. Investigators can learn how these tactics impact their ability to determine the fire's origin and cause. This research promotes dialogue between firefighters and investigators, improving the effectiveness of fire services. The data collected from the experiments will be analyzed with fire investigation experts across the U.S., and the findings will lead to an online training program to share the science of fire investigation with professionals worldwide.

Keywords

💡Fire dynamics

Fire dynamics refers to the study of how fires grow, spread, and interact with different environments. In the video, fire dynamics is crucial for understanding how fires behave in a home setting and how the fire service can operate more safely and efficiently. The research examines the factors that influence the progression of a fire, such as ventilation, which is tested by opening doors or windows.

💡Ventilation

Ventilation is the process of introducing air into a fire environment, which can affect fire growth and behavior. The video explores how opening a door or window during a fire can change the burn pattern, oxygen levels, and overall fire dynamics. The experiments focus on how these changes impact fire damage and the ability of investigators to determine the cause and origin of the fire.

💡Burn patterns

Burn patterns are the visible effects left by fire on materials, which can help investigators determine the origin and cause of the fire. In the video, burn patterns are a key focus, as the researchers study how different fire conditions, such as changes in ventilation, affect the burn patterns within a structure. These patterns are essential for fire investigation.

💡Area of origin

The area of origin refers to the location where a fire first ignites. Identifying the area of origin is a critical goal for fire investigators. The video emphasizes how understanding fire dynamics and burn patterns can help investigators more accurately pinpoint the area of origin, especially in complex fire scenarios influenced by ventilation and other factors.

💡Thermocouples

Thermocouples are devices used to measure temperature at various points within a fire environment. In the video, thermocouples are placed throughout the structure to monitor temperatures from the ceiling to the floor, providing valuable data on the hot gas layers and cool air within the building. This data is crucial for analyzing fire behavior and understanding how different factors influence fire growth.

💡Pyrolysis

Pyrolysis is the chemical decomposition of materials due to high heat, even in the absence of flames. In the video, pyrolysis is mentioned as a phenomenon that occurs during a fire, especially in areas where there is heat but no active combustion. Understanding pyrolysis helps investigators differentiate between areas affected by flame and areas experiencing thermal effects.

💡Suppression tactics

Suppression tactics are the strategies used by firefighters to control and extinguish fires. The video highlights how different suppression tactics, such as ventilation choices, can impact fire behavior and the resulting fire patterns. This information is important not only for firefighters but also for investigators, as it affects their ability to analyze the scene and determine the cause of the fire.

💡Oxygen concentration

Oxygen concentration refers to the amount of oxygen present in the air, which is a critical factor in fire growth and sustainability. In the video, oxygen levels are monitored at different heights within the structure, and the researchers observe how the fire's behavior changes as oxygen levels drop. A reduction in oxygen can cause a fire to self-extinguish, influencing the fire damage and burn patterns.

💡Fire investigation

Fire investigation is the process of determining the cause, origin, and progression of a fire. The video focuses on how the research conducted by the UL Firefighter Safety Research Institute aims to improve fire investigation techniques by providing better understanding of fire dynamics, burn patterns, and the impact of ventilation. The ultimate goal is to help investigators make more accurate determinations.

💡Cross-discipline dialogue

Cross-discipline dialogue refers to communication and collaboration between different professional fields. In the video, the importance of dialogue between the fire suppression community and fire investigators is emphasized. By sharing insights and findings, both groups can improve their practices, leading to safer firefighting tactics and more accurate fire investigations.

Highlights

The UL Firefighter Safety Research Institute has conducted a decade of research on fire dynamics, focusing on how fires grow and spread in homes.

The research is crucial for firefighters to understand fire behavior, enabling them to operate more safely and efficiently on the fireground.

The project uses full-scale structures and changes ventilation by opening doors or windows to study its impact on burn patterns.

Replicate fires are conducted in closed buildings initially, and then openings are introduced to observe changes in fire damage and growth rate.

One goal is to understand how ventilation affects the investigator’s ability to determine the area of origin and cause of the fire.

The research aims to refine fire investigation methods by focusing on burn patterns and how they can lead to the area of origin.

The research uses bidirectional probes to measure temperature and gas velocity, indicating whether hot gases are exiting or fresh air is entering.

Thermocouples are placed throughout the structure to monitor temperature at intervals, from ceiling to floor, helping to understand the hot gas layer.

The project also monitors oxygen concentration at different heights to study the interaction between oxygen availability and fire dynamics.

Pressure taps in the wall measure areas of high and low pressure, providing further insight into fire behavior in enclosed spaces.

Energized household items such as lamps, outlets, and electronic devices are used to observe their behavior during a fire.

Documenting the house before and after the fire, as well as during furniture removal, helps in understanding the impact of the fire on the structure.

The research examines thermal effects, combustion, and pyrolysis in detail, linking these phenomena to patterns observed during the investigation.

The project has implications for both firefighters and investigators, helping them understand how ventilation and tactics impact fire patterns.

The research encourages dialogue between suppression firefighters and investigators, fostering cross-disciplinary understanding and improving overall effectiveness.

The project’s findings will be used to develop an online training program for fire investigators worldwide, making the science accessible and applicable in real-world scenarios.

Transcripts

Over the past ten years the UL Firefighter Safety Research Institute

has been conducting research examining fire dynamics.

How fires grow and spread in a home has been extremely important

to the fire service to understand how they can operate

as safely and efficiently as possible on the fireground.

We wanted to take what we’ve learned over the past ten years and expand that into the fire investigation community.

Our project is using full-scale structures

where we’re going to change the ventilation by opening a door or opening a window

and look at its impact on the burn pattern.

So initially we’ll conduct replicate fires with the building closed

and then we’ll start to make openings in the building in subsequent tests

and see how that changes the fire damage,

the growth rate of the fire, the impact of the fire,

and how that would impact the investigators ability

to find the area of origin as well as the cause of the fire.

But our real focus is on the area of origin and how the patterns might lead the investigator to that end.

So let’s take a walk through the colonial.

So as we make entry you’ll notice these probes.

These are bidirectional probes and they’ll get swung in front of the door when we’re ready to test.

They measure temperature as well as gas velocity, which means that we get

not only the speed of the gas but the direction it’s going.

So we can tell whether hot gasses are exiting the building or fresh cool air is entering the building.

Throughout the structure we have thermocouples

and you’ll see here that they stretch all the way to the ceiling so we’re measuring

at intervals of every foot from the ceiling all the way down to the floor

so we have an idea of where the hot gas layer is at all times and where the cool air may be.

We’re also monitoring for oxygen concentration so here we have an oxygen intake

at four feet above the floor and another at four inches above the floor.

You’ll notice that there’s several taps in the wall and those measure pressure.

So they’re intended to tell us where we have areas of high pressure and areas of low pressure.

We have carpet we have outlets that are energized you can see the lamps are lit up

we have some other targets such as the phone on the table

we have a small battery powered electric clock.

The television is also energized. So again we’re looking for effects that

investigators might see how does it fail how does it melt how does it come apart

and then we’ll understand the conditions that that occurred. So that’s the important part here

that we have the measurements here to go along with the phenomena,

the resulting phenomena that we’re seeing so that we can develop some cause and effect relationships

We’ve documented the house with photographs prior to the fire

after the fire we’ll document it again, and then as we remove the furniture

we’ll take photographs and document layers of the house, pull up the flooring and document the subfloor as well.

Sofa Ignition in 4, 3, 2, 1, Ignition.

Passing 212 at the ceiling on the living room

At the back of the sofa starting to see some drop down on the carpet behind it.

Oxygen’s dropping. Passing 15% it’s going to put itself out.

Starting to see temperatures drop, flames are disappearing,

oxygen is down to 9% in the upper layer

temperatures are falling in the living room temperatures are below 650 at the ceiling and falling.

So what we need to do now is start to remove the furniture carefully

start to dismantle the scene and document the scene with photographs

and pull the layers back so we can look at and get a better view of the pattern on the wall and a better view of the pattern on the ceiling.

But these are all patterns or fire effects that need to get put together to get an understanding

of how all of the puzzle pieces fit together between where the fire damage is,

where there was oxygen present and where there wasn’t oxygen present.

Where we actually had flame and combustion and where we just had thermal effects or pyrolysis ongoing in the room.

This project is important to a number of areas;

one, it’s important to our suppression firefighters

because they can really start to understand the fire pattern within the structure

and the impact of ventilation on that fire pattern.

And we also look at it to our investigators

that we can actually start to understand the impact of the ventilation or chosen tactics into their investigation looking at cause and origin.

And another important aspect of it – it actually hopefully drives that

investigative community to really have discussions with the suppression community

so they start to understand how to operate or how to choose your tactic suppression-wise,

but then the investigators can start to understand the impact of the selective tactics

into their investigations,

so it cause that dialogue across the cross-disciplines which then educates both sides

and it makes us a more effective service overall.

As we finish these experiments we will continue to analyze all of the data and video

with our technical panel of fire investigation experts around the country.

We’ll put together key findings and develop an online training program

that will easily take the science to the streets for fire investigators around the world.