Meet the Speaker: Patrick van Hees

Internationally renowned fire practitioner, researcher, and teacher Professor Patrick van Hees recounts his professional journey and talks to Nicholas Dynon about the urgent need for system thinking in fire safety engineering.

Patrick is currently Head of Department for the Department of Building and Environmental Technology at Lund University. He holds a PhD from the University of Gent (Belgium) in wind aided flame spread of floor covering.

In 1995, he moved to SP Fire Technology (now RISE) in Sweden where he started as project manager and became research manager in 2002. In 2007, he moved to Division of Fire Safety Engineering of Lund University in Sweden and became professor of fire safety engineering.

He is also guest professor at the University of Gent in Belgium where he is course responsible for the Fire Performance Based Design course within the International Erasmus Mundus Master of fire safety engineering. He is chair of ISO TC92 SC1 (Fire Initiation and growth) and convenor of ISO TC92 SC1 WG 7, Large and intermediate scale fire test methods.

ND : How did you get into fire engineering?

PVH: I studied civil engineering and started out as an electromechanical engineer with speciality in high power electricity. I did my Master of Civil Engineering with the Fire Lab at the University of Ghent in Belgium and wrote a thesis on fire resistance of insulated pipes.

At the end of my master thesis, I got my degree, and then they needed somebody to start at the Fire Lab there to help with fire testing and fire research. So they asked if I could join them for a short time – they tended to offer temporary contracts of two years – and I said yes. I still had my military service to do, but I thought if I work for two years before going to military service it could be nice to have some money already in my pocket!

But then one of my colleagues left the laboratory and we were a bit short of staff, so the professor said, “Okay, can I convince you to do a PhD and stay longer?” So I ended up there doing my PhD and then I went to Sweden afterwards. That’s how I got into fire. My original idea, to be honest, was to become maybe an engineer at an electrical power plant somewhere in Belgium. Now, luckily, I’ve been involved a lot in projects with cable fires and functional performance of cables under fire conditions, so I’ve retained a little bit of electricity in what I’ve done so, which is nice given my background in that.

ND: What was your research area for your PhD?

PVH: I looked at the flame spread of floor coverings, mainly in escape routes. Not too many people have worked with floor coverings, except for some people in Australia who’ve worked on it as well as NIST in the US. Specifically, I looked into the possible risks associated with carpets and other floorings in escape ways and their susceptibility to wind-aided flame spread, which results in quick flame spread. We could see in a number of scenarios that quick flame spread occurred and that the flame properties of floor coverings should be taken into account.

I used the word “wind-aided” when I translated my thesis, but it’s perhaps better described as “co-current” flame spread. This refers to when the flames are in the same direction as the flow of the air – both the smoke and also the cold air is pushed away so that the flames are leaning towards the non-combustible or non-ignited floor covering. This results in a much quicker flame spread, and it is dependent on the conditions in the stairwells, such as open or closed doors, and so on.

I did a little bit of playing with different configurations. Most of the time the cold air will go towards the fire, which results in post-flame-spread, but in certain conditions you can get wind-aided, or co-current, flame spread, resulting in a very quick flame spread in a corridor.

One of my conclusions was that when using floor coverings, whether it’s linoleum, PVC flooring, wooden floors, carpets and so on, one should be cautious and assess the risk. Of course, in many countries, there are regulations that prohibit combustible flooring or require a very low flame spread floor covering. But I am always a little bit worried when I find myself in hotels with very thick carpets in the escape routes or in the stairwells!

ND: The title of your presentation for the conference is “The urgent need for system thinking in Fire Safety Engineering, from regulations and performance based design to education”. There’s a lot to unpack in that title. Can you break it down?

PVH: Yes, it’s a long title, but it’s a similar title to a keynote lecture I gave at Interflam [14th International Conference and Exhibition on Fire Science and Engineering, London] in 2016. The thing is that for fire safety we see quite often that there is a focus on a specific item, whether it’s the fire resistance of the walls or the doors, the wall linings, etc. But in reality there’s a combination of different materials and products to consider.... Read more in the magazine.