A tight, historic cellar. Arched ceilings. Long corridors. Tiny shafts. We faced a design wall: to keep routes tenable, we needed twice the extraction that the building could carry. At that point, I've failed as an engineer - I've reached my limit and could not find a solution.

Some time later, a solution appeared in my head from nowhere —what if the fan changed with the fire? Not in a crude on-off way, but by tracking temperature, exploiting density changes, and chasing constant mass flow instead of fixed volume.

We unpack the moment this clicked, the fan physics behind it, and why hotter smoke can actually make extraction easier if you use the margin correctly. You’ll hear how we oversized the fan, ran it at a lower frequency in ambient, then ramped as temperatures rose to keep kilograms per second steady. That adaptive control boosted cubic meters per second right when the layer needed support, eased plug-hole entrainment, and stabilised makeup air velocities. We walk through the thermodynamics, the electrical and pressure implications, and how these pieces form a practical control strategy for retrofits and new builds.

To ground the idea, we share two paths to proof. First, CFD with user-defined control that reads gas temperature each time step and updates fan frequency with smoothed delays to prevent oscillations—capturing the real feedback loop between fire and system. Then, full-scale container burns with live control showed the same trends from 20 to over 500 degrees: falling duct pressures, lower fan power at heat, and the headroom to increase volumetric extraction without breaking limits.

Thinking about it now, this idea is a part of many other concepts that I describe together. To show a way how we come from the simple framework—Smoke Control 1.0 (empirical, static), 2.0 (CFD-informed, still static), into a new smoke control 3.0 (adaptive, feedback-driven)—and explore how this thinking can reshape underground venues, car parks, tunnels, pressurisation, and natural ventilation.

If you care about safer evacuation, smaller shafts, lower velocities, and systems that work with physics rather than against it, this story is for you. Subscribe, share with a colleague who designs smoke control, and leave a review with your toughest question so we can tackle it next.

Reading material:

- Can smoke control become smart?

- Transient characteristic of the flow of heat and mass in a fire as the basis for an optimised solution for smoke exhaust

- Smart Smoke Control as an Efficient Solution for Smoke Ventilation in Converted Cellars of Historic Buildings

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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.

A fire in a public venue happened again. No, I am not talking about the one in Switzerland. Since the tragic New Year celebration, we had one more near-miss in Madrid on Jan 10th 2026... In fact, who knows how many we actually had? It is a tragedy that feels like it is playing on repeat...

In this podcast episode, we try to dig into why nightclub fires follow the same script decade after decade—what are the parts of the pattern, and what can we do through smarter design, honest modelling, and real enforcement. With guest Lazaros Filippidis from the Fire Safety Engineering Group at the University of Greenwich, we map the chain of failure: combustible acoustic treatments under low ceilings, narrow or locked exits, stair “chimneys” that pull smoke toward escaping crowds, and furniture layouts that turn doors into traps.

We talk about human behaviour. People head for the entrance they know. They hesitate when cues conflict—especially if pyrotechnics were part of the show minutes earlier. Phones come out. People respond in such a way not because people are foolish, but because recognition takes time in loud, dark, crowded spaces. The fix isn’t shaming; it’s designing for how people really act: outward‑opening doors, multiple distributed exits, better signage, immediate lights up and music down, and staff who redirect flow on instinct.

For engineers, we go beyond textbook ASET vs RSET and show how coupled fire–evacuation modeling reveals the true picture as heat, irritants, and visibility degrade movement and decision‑making. We make the case for sensitivity analyses: add more patrons, block an exit, switch to ultra‑fast fire growth, drop a service trolley into a corridor, and see in what scenarios your modelling results collapse. We can find the bottlenecks, and if we do, we can fix them. With practical tools—from zone models to agent‑based simulators—you can find vulnerabilities before opening night and recommend changes that add crucial minutes or even seconds.

It was a tough episode to record, especially since there is not much new we have learnt about human behaviour or fire growth in such facilities... I hope this provides some food for thought and fuels future design considerations.

If you are interested in modelling done with buildingExodus, for which Lazaros is one of the developers, please go and visit the FSEG website.

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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.

Today we sit down with safety science leader George Boustras - a professor at European University Cyprus, UNESCO Chair in Disaster Risk Reduction and Societal Safety in South East Mediterranean and founder of Centre of Excellence in Risk & Decision Sciences (CERIDES). With George we try to examine fire engineering from the wider safety lens, exploring why culture—not just compliance—decides outcomes.

We unpack a practical definition of safety as managed risk and follow the hard-earned lessons from Bradford City, King’s Cross, and Piper Alpha to today’s performance-based thinking. George explains why engineering effort should focus where complexity and uncertainty truly demand it, and why modeling without common sense leads to false confidence. We dive into real-world behavior in tunnels, the gap between ASET/RSET and what people do under stress, and how a strong safety culture aligns design, operations, and maintenance across a building’s life.

The conversation tackles urgent risks that don’t fit old patterns: lithium-ion battery fires in dense urban housing, micromobility charging in corridors, and emerging wildfire exposure in regions with little prior experience. We outline what works—education that starts early and persists, firm rules with clear roles for citizens, measurable campaigns, and system-level discipline. Borrowing from occupational safety, we highlight safety cases, annual risk assessments, and psychosocial insights that improve decision-making. And we spotlight the “fire scenario” as a powerful, testable playbook for how alarms, fans, dampers, and doors should behave, creating a living matrix for commissioning and maintenance.

If you care about moving beyond checklists to safety that holds up under pressure, this conversation is for you. Subscribe, share with a colleague, and leave a review with your biggest safety culture challenge—we’ll feature the most compelling ideas in a future episode.

Learn more about CERIDES at https://cerides.euc.ac.cy/

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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.

Fires in informal settlements and humanitarian settings rarely make headlines, but they define daily life for millions. We sit down with Kindling founder Danielle Antonelis to trace a four-year arc from the non-profits early days and ideas to grounded results: a global shelter database, experimental campaign with 20 full-scale burns, and a learning model that puts residents first. The core shift is profound—safety isn’t a box to tick; it’s a practice repeated and refined across homes, lanes, and entire neighborhoods.

We dig into how Kindling translated complex fire science into choices that matter under pressure: where to place a door, how a roof fails, why flames jet from openings, and what that means for neighbors two meters away. Danielle shares how the team balances radical transparency—releasing raw data for engineers—with clear, concise guidance tailored to humanitarians and communities who need to act fast. We also unpack the governance gap: codes designed to protect everyone tend to protect only those who can comply. Performance-based approaches and policy work become lifelines when regulation fails to reach the most vulnerable.

The conversation confronts emerging risks head-on. Secondhand batteries and uncertified devices flow into low-resource markets, creating hazards that standard messaging doesn’t address. Rather than preaching certification, Kindling teaches signs of battery distress, safer charging habits, and context-specific tactics that residents can own. In Cape Town—where informal settlements and service delivery are acknowledged—Kindling is piloting conflict-resolution between residents and firefighters, clarifying the fastest emergency call routes, and coordinating tactics within real infrastructure limits.

If you care about fire engineering, humanitarian response, or how policy meets practice, this story offers a blueprint: open data, resident-led learning, and practical tools that scale. This is also highly relevant to all fire safety engineers - how we communicate fire science, how we reach with our message to key stakeholders, and how we consider what 'safety' really is.

If you would like to hear how it started, check out episode 34: https://www.firescienceshow.com/034-fire-safety-as-a-human-right-not-a-privilege-with-danielle-antonellis/

If you want more context how it looks on the ground: https://www.firescienceshow.com/077-informal-settlements-we-need-solutions-not-gadgets-richard-walls/

Also make sure to check out Kindling website here: https://kindlingsafety.org/

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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.

Catastrophes don’t happen because of one bad decision; they happen when many small assumptions fail at the same time. I take this opportunity to talk about my thoughts related to the Wang Fuk Court fire in Hong Kong. I attempt to examine how a routine ignition escalated into hundreds of compartment fires across multiple buildings—and what that says about the limits of our current fire engineering. Keep in mind these are the opinions of myself!

We start by challenging a comforting belief: that prescriptive rules and performance-based designs can handle “the big one.” They can’t if the event steps outside the envelope. You’ll hear why compartment-focused strategies struggle when geometry and wind synchronize flames, how cavity spaces in light wells amplify heat and acceleration, and why nonlinearity means a modest increase in heat release can explode into a different regime of flame spread and radiation.

We break down the ingredients that turned risk into disaster: star-shaped towers with interior wells, bamboo scaffolding and netting near openings, temporary polystyrene window covers, and a dry monsoon pushing firebrands far beyond the origin. We also dig into response realities—why sprinklers and hydrants are sized for one or two compartments, not dozens at once—and the hydraulic and access limits firefighters face at height.

Most importantly, we translate insights into action. Learn how to make extreme scenarios explicit with safety cases during construction, align tests with actual exposure on façades and cavities, replace flammable temporary coverings with noncombustible barriers, and plan targeted, temporary suppression where geometry concentrates risk. No single fix will prevent every tragedy, but narrowing the gap between our models and real fire behavior can save lives and homes.

If this conversation helped you see fire risk differently, subscribe, share the episode with a colleague, and leave a quick review—what’s the most overlooked hazard you think we should explore next?

I would like to wish you a Happy New Year 2026! Let's hope it is a year of thriving fire safety.

Cover image: By am730 - YouTube: 大埔宏福苑五級火 蔓延7幢樓宇 至少13死28傷一消防殉職 – View/save archived versions on archive.org and archive.today(At 0:46 of the video), CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=179003054

Wikipedia article about the Wang Fuk Court fire: https://en.wikipedia.org/wiki/Wang_Fuk_Court_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.

I would like to take this opportunity to wish you Merry Christmas, a great time with your families, a bit of rest and time to reflect, and an awesome 2026 to come!

If you are desperate for fire science on Christmas Eve, check out the OFR report on open car park fires, which we were able to contribute to: https://www.gov.uk/government/publications/fire-safety-open-sided-car-parks

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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.

Today we cover another branch of safety of Battery Energy Storage Systems (BESS), that is explosion prevention in mitigation. I always thought you can either end with a fire or with an explosion, and boy I was wrong... but we will go back to this later. Now I bring on Dr. Lorenz Boeck (REMBE) and Nick Bartlett (Atar Fire) to unpack how gas released during thermal runaway turns a container into a deflagration hazard, and what it takes to design systems that actually manage the pressure, flame, and fallout. This is a tour through real incident learnings, rigorous lab data, and the evolving standards that now shape best practice.

We start with the fundamentals: from the overview given by NFPA855, why modern BESS enclosures—with higher energy density and less free volume—see faster pressure rise, how gas composition varies by cell and manufacturer, and why stratification matters when lighter hydrogen-rich mixtures sit above heavier electrolyte vapors. From there, we translate UL 9540A outputs—gas quantity, composition, flammability limits, burning velocity—into engineering decisions. NFPA 69’s prevention path typically relies on gas detection and mechanical ventilation designed to keep concentrations below 25% LFL, validated with CFD to capture obstructions, sensor placement, fan ramp, and louver timing. NFPA 68’s mitigation path kicks in if ignition happens, with certified vent panels sized to the actual reactivity and geometry, relieving pressure and directing flame away from exposures.

A major takeaway: the latest NFPA 855 now often pushes for both prevention and protection. Even with active ventilation, partial-volume deflagration hazards remain, especially as cell capacities rise and gas volumes scale up. We dig into venting trade-offs—roof vs sidewall, snow and hail loading, heat flux to back-to-back units—and how targeted sidewall venting can deflect flame upward while reducing weather vulnerabilities. Perhaps most critical, we talk about late deflagrations observed hours into large-scale fire tests, when changing ventilation conditions allow pockets to ignite. Active systems aren’t built to operate throughout a long fire, so passive venting becomes essential during and after ignition.

Whether you’re a fire engineer, AHJ, insurer, or developer, this conversation connects the dots between lab data, CFD, and field realities. You’ll leave with a clearer view of how to apply UL 9540A, NFPA 68, NFPA 69, and NFPA 855 in a world of stacked containers and supersized cells—plus where training can shorten your learning curve.

If you are interested by the course given by colleagues in Lund in January 2026 - here it is: https://www.atarfire.com/event-details/nfpa-855-8-hour-training-lund-university

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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.

A facility with 105 synchronized fans pushing hurricane-class wind across a full-size house while a live fire... This is not science fiction - this is a real research capacity that helps us re-shape our knowledge on the full scale building ignition, fire spread, and failure. That’s the stage at IBHS, where we dig into how wind-driven fire behave differently to small-scale and how tiny choices around a building can decide its fate. Together with my guest - dr Faraz Hedayati, we go from embers generation and fire spread studies, to urban conflagration research.

We start with embers, the quiet culprits behind so many structure losses in the WUI. Embers aren’t a single threat but a spectrum of sizes, temperatures, and lifetimes that ride shifting eddies and stall in stagnation zones. We talk through what full-scale tests reveal: glowing ember lines at the base of walls, roof reattachment zones where deposits spike, and the hard truth that counting particles matters less than controlling where they land. The guidance is clear and actionable—noncombustible vertical clearance, hardened vents, defensible space within the first five feet—because under wind, any component can become the first domino.

Then we tackle conflagration: how a spot fire becomes a neighborhood problem. IBHS’s shed-to-structure and fully furnished burns show exposure arriving in pulses, not a smooth curve. Collapse chokes flames and then reinvigorates them, creating multiple peaks where materials succeed or fail on a timer. We compare 30 mph to 60 mph winds and see how plumes lose buoyancy, flatten into the target, soften vinyl frames, and push glazing inward. Separation distance emerges as a decisive lever: around 10 feet, continuous flame contact dominates; at 20 feet and beyond, exposure becomes intermittent and materials can win—unless “connected fuels” like vehicles, fences, and decks bridge the gap.

The takeaway isn’t a silver bullet. It’s a layered defense: control embers, clean the near-wall zone, harden openings, choose noncombustible claddings, and increase spacing where possible. Small-scale testing and modeling still matter, but wind-driven fire demands validation at full scale to catch the peaks, the collapses, and the failure modes no bench setup can mimic. If you care about wildfire resilience, urban design, or building safety, this conversation offers a rare, data-rich look at how communities ignite—and how we can change the odds.

Learn more about IBHS research at https://ibhs.org/risk-research/wildfire/

Cover picture courtesy of dr Faraz Hedayati.

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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.