Fire Science Show

Welcome to another Fire Fundamentals. This time the episode is focused on various extinguishing technologies. Invited guest - Bogdan Racięga, Director at Baltic Fire Laboratory and expert in fire protection systems breaks down the fundamental differences between suppression and extinction technologies and how they work in real-world applications.

• Clear distinction between suppression systems (control fires while meeting temperature criteria) and extinction systems (must completely extinguish fires)
• Types of fire protection systems including water-based (sprinkler, water mist), foam, aerosol, and gas systems (no fire-balls :))
• Technical parameters affecting performance: K-value, nominal working pressure, RTI, discharge areas
• Areas of application, eg. why water mist systems can often be preferred for high-rise buildings due to smaller piping and reduced weight
• How temperature ratings and RTI affect sprinkler activation timing and performance
• Challenges with concealed sprinklers including maintenance issues and delayed activation
• Testing procedures for water distribution patterns and certification processes
• Differences between high-pressure and low-pressure systems in various applications
• nuances related to the role of an accredited laboratory (ISO 17025) and a certification body (ISO 17065)

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The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

Jet-fan systems effectively control smoke in car parks by creating directed airflows that transport smoke from one point to another, similar to how longitudinal ventilation works in tunnels. These systems offer cost-effectiveness and simplicity by eliminating ductwork while providing powerful smoke management capabilities when properly designed and understood.

• Jet Fans create momentum transfer through air entrainment rather than directly moving smoke
• Two distinct operational modes exist: smoke clearance (reducing thermal stress) and smoke control (maintaining clear firefighter access)
• Systems require careful balancing of extraction capacity with Jet Fan thrust force
• Optimal design typically requires CFD modeling followed by hot smoke testing for verification
• Jet Fan activation timing presents challenges for evacuation - usually delayed until occupants exit
• Systems excel in tunnel-like geometries but struggle with complex layouts (the "Tetris rule")
• Particularly effective against heavier-than-air gases like LPG or EV battery fire emissions
• European standards now available through EN 12101 family for design guidance

If you need design assistance with Jet Fan systems for your projects, email me directly at [email protected]. 

Further reading:

- Jet-Fan Systems in Car Parks Design Methods: an Overview and Assessment of Performance

- Our in-depth multiparametric study on car park ventilation

- A. Król and M. Król, Study on numerical modeling of jet fans

- Thunderhead's guide to modelling jet-fans in FDS

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The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

This episode explores the invaluable contributions of community participation in fire safety technical committees. Joining committees is not just about sharing expertise; it’s a journey that transforms careers and fosters growth. Our guests, Birgitte Messerschmidt and Kees Both, reveal how their experiences in various committees, including the NFPA, ISO, ASTM and CEN, have shaped their professional paths. 

As we dive deeper into the intricacies of committee politics, our guests candidly share the challenges and rewards of engaging in this important work. They emphasize how participating in committees enhances one's career and contributes to the greater good by improving fire safety standards. This is an essential discussion for any engineer, especially those starting their careers, as they navigate the complexities of working with diverse stakeholders.

If you just felt inspired to join a committee, please look here:

• https://www.sfpe.org/membership-communities/standingcommittees
• https://www.nfpa.org/for-professionals/codes-and-standards/standards-development/technical-committees/committees-seeking-members
• https://www.cencenelec.eu/get-involved/small-and-medium-enterprises-smes/tools-for-smes/getting-involved/

Or just shoot us an email, or reach out at LinkedIn. We will help you out!

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The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

With the emergence of electric vehicles, fire safety and dynamics have entered a new domain, raising crucial questions about existing protocols, design fires and data gaps. Today, our Wojciech Wegrzyński welcomes Zahir, Associate Prof. at University Putra Malaysia, to discuss the findings from their latest papers, compare methodologies, and highlight the differences between traditional combustion engines and electric vehicles. 

The conversation covers various topics, from the nuances of fire dynamics to the importance of context in risk assessment. Zahir shares his extensive experience studying vehicle fires, including the evolution of electric vehicle dynamics that users should never ignore. With thought-provoking insights, this episode emphasises the increasing need for robust, comprehensive data regarding car fires and the unique challenges posed by electric vehicles. 

Join us in this engaging exploration of fire safety science, and don't forget to subscribe, share, and leave a review!

Papers! PAPERS:

Miechówka & Węgrzyński: Systematic Literature Review on Passenger Car Fire Experiments for Car Park Safety Design

Zahir & César Martín-Gómez: Evaluating Fire Severity in Electric Vehicles and Internal Combustion Engine Vehicles: A Statistical Approach to Heat Release Rates

Podcast episode 135 - Contemplating a car park design fire

(and the paper by J. Hodges from last year is here)

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Badania przedstawione w odcinku podcastu omawiane przez dr Wojciecha Węgrzyńskiego przeprowadzono w projekcie realizowanym an podstawie umowy UMO-2020/37/B/ST8/03839 do projektu badawczego nr 2020/37/B/ST8/03839 pt. Skutki oddziaływania wiatru na pożary budynków w wieloparametrycznej ocenie ryzyka z wykorzystaniem metod numerycznych.

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The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

This episode emphasises the value of focusing on simple things in fire safety engineering, something we somehow miss when we go too deep into the technical details of our projects. I've looked at eight different aspects of fire safety - inspired by the CPR requirements, and I've added resiliency, redundancy and suppression to them. By promoting straightforward guidelines like evaluating material combustibility, ensuring effective egress routes, and engaging with rescue services, architects and engineers can significantly enhance building safety practices. 

In this episode, we talk about:
• Simple methods yield effective fire safety solutions 
• Importance of adhering to foundational fire safety principles 
• CPR’s five essential requirements for construction safety 
• Load-bearing capacity and material combustibility considerations 
• Strategies for minimising fire spread between structures 
• Importance of clear egress pathways for building occupants 
• Opportunities for enhancing rescue team safety via communication 
• Emphasis on redundancy and resiliency in fire safety systems 

Each foundational principle allows fire safety practitioners to implement effective strategies that can lead to safer buildings and improved occupant outcomes.

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The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

In this episode of Fire Fundamentals, together with Dr Sara McAllister, we dwell on how stuff burns... And it is far from an easy question. While the general theme of the episodes is porous fuels, we discuss them from different angles, highlighting the similarities and differences between foamed and permeable materials.

In this episode, we cover:

• role of permeability, entrainment and forced flows through porous fuel beds;
• differences in physical properties between porous materials and their bulk forms;
• ignition (flaming and smouldering) of porous fuels;
• natural and artificial fuels, open and closed cell fuels;
• hazards specific to porous fuels in wildfires and in building fires;

And also a bit of discussion on future research of Dr McAllister along with the need for canonical tests to characterize their flammabaility.

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The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

Can a tiny amount of bio-protective coating completely change the fire behaviour of mass timber logs? If you asked me that some time ago, I would say it would probably be neutral.

Can a 0.5 x 0.5 m free-standing log of timber smoulder through without any external exposure to fire? If you asked me that some time ago, I would say no, and base that on observations of dozens of logs like this.

Yet, in Australia they’ve burned. And the hypothesis was that it has something to do with the preservative treatment.

My guest today, Wenxuan Wu from The University of Queensland was tasked with researching this problem and showed us the workshop used for this. In this podcast episode, we dive deep into measurements carried out in fire laboratories on the material scale and how use of different methods gradually increases our understanding of the problem. Their pursuit also opened new questsions - for example, why if timber would be subject to a very strong heat flux, the smouldering would not work anymore? This was also answered in the discussion.

If you would like to learn more about Wenxuan’s research, please refer to the published papers:

•  Experimental study on the factors affecting smouldering behaviour of CCA-treated wood
• Deactivation of chromated copper arsenate as a catalyst in smouldering of wood

Also, this talk summarises the best poster at ITB-FRISSBE Summer School. What an event that was. Once again, we would like to thank our sponsors for that!

https://www.itb.pl/2024-summer-school/

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The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

If we truly want to account for the population at a disadvantage in evacuation, there is only this much we can do with the current approach... Pre-evacuation time distributions, walking speeds, and so on only tell us a part of the story - the story of your average person within an average population, with an average walking speed and average response. While these models are undoubtedly useful in engineering, there is perhaps a better way.

My friend and guest Enrico Ronchi is trying to find this way through his new ERC Consolidator grant, "Egressibility: a paradigm shift in evacuation research". In this grant, instead of following the main path, he is focusing on stuff we do not know - how to characterise disabilities and understand them better (also through the lens of health and medicine), how to quantify the disadvantages at large, and how to solve potential issues for those who those at the largest risk.

In this episode, you will learn about Enrico's ideas and the edge of the knowledge we have today. Some key points covered are:

• Insights on paradigm shifts in evacuation science
• Introduction of the concept of "egressibility"
• Importance of understanding functional limitations in emergencies
• Shift from agent-based models to inclusive data-driven models
• Use of technology, like VR, for immersive research experiences
• Need for changes in regulations for better evacuation safety

You may also like to read the paper by Guylène Proulx, which introduced egressibility as a concept - available here.

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The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

In the aftermath of the LA Pacific Palisades Fire, I've decided that instead of inviting one expert to discuss the event, I will give a voice back to those who already participated in the Fire Science Show and explained this fire (months and years before it happened).

In this episode, we recap Wildland-Urban Interface fires, with a focus on the "urban" part. We cover conditions in which such fires may happen and factors that contribute. We discuss the role of community preparedness and pathways in how those fires "attack" individual households. We talk a lot about embers and some ideas on how to mitigate them. Finally, we discuss the evacuation from WUI fires.

Some politics, a lot of science, decent amount of answers to most urgent questions. I hope you will enjoy!

Episodes and speakers featured in this podcast:

• 069 - Challenging fires at the wildland-urban interface (WUI) with Michael Gollner
• 117 - Global wildfire emergency and the key role of FSEs with Albert Simeoni
• 156 - Trigger Boundaries with Harry Mitchell and Nick Kalogeropoulos
• 159 - The WUI Problem with Michele Steinberg and Birgitte Messerschmidt
• 161 - Community evacuation with Enrico Ronchi and Max Kinateder

You can always find current episodes on wildfires at https://www.firescienceshow.com/category/wildfires-wui-and-wind/

The history of Japanese urban fires is covered in the paper Large Urban Fires in Japan: History and Management by Yoshioka H. et al. 

Cover image credit: By Toastt21 - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=157682430
From the Wikipedia summary of the LA Palisades Fire at https://en.wikipedia.org/wiki/Palisades_Fire

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The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

This episode delves into the financial aspects of fire safety in building design, highlighting the balance between cost and effectiveness. My guests - prof. Thomas Gernay and Chenzi Ma from Johns Hopkins University share insights from their NIST-sponsored research project on cost-benefit analysis and loss estimation for structural fire safety. In the discussion, we explore the differences between prescriptive and performance-based approaches, discussing insights from a comprehensive analysis of over 130 structures and how to better allocate resources for passive fire protection measures.

In this episode, we cover:
• Understanding fire safety costs in construction 
• Insights on prescriptive vs. performance-based design 
• The importance of maintenance and lifecycle cost assessments 
• Analyzing fragility functions for predicting fire damage 
• Cost dynamics across different building occupancy types 
• Future developments for implementing this analytical framework in practice

Please find here useful links about the project:

• Paper 1 on the costs: https://www.sciencedirect.com/science/article/pii/S0143974X24000671?
• Paper 2 on the numerical model of the NIST tests on composite floors: https://www.sciencedirect.com/science/article/pii/S037971122400095X
• Paper 3 on the fragility curves (freshly accepted): https://www.sciencedirect.com/science/article/pii/S0951832025000237
• Github: https://github.com/Chenzhi-Ma/web_v2

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The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.