July 20, 2022

059 - Residential fire safety with Dan Madrzykowski and Charlie Fleischmann

059 - Residential fire safety with Dan Madrzykowski and Charlie Fleischmann

How much the fire scene at households has changed over the last 30 years? Why modern furniture burns worse than one made with wood, cotton and other natural materials? And what does that mean to firefighting? What challenges do modern firefighters face fighting residential fires... There is so many questions to be asked about residential fires, and in this episode, I answer a lot of them with the firefighting research legends - Dan Madrzykowski of the UL Fire Safety Research Institute and professor Charlie Fleischmann from the University of Canterbury.

After listening to this episode you must check the website of the UL FSRI! That is a vault fille with fire science gold, not to be missed by anyone passionate about fire safety.

And if you are here to find some info about the Fire Hose Prop we have discussed, seek no more - just follow this link to learn all about it.


[00:00:00] Wojciech Wegrzynski: Hello, everybody. Welcome to the Fire Science Show. I've promised some hardcore engineering and science today, and I'm going to deliver. So when you think about the most dangerous places around. In relation to fire safety. These are not truly shopping malls, airports, or car parks or skyscrapers or.

[00:00:21] Wojciech Wegrzynski: Whatever we used to. The most dangerous place. It's most like your home and. In fact, most of the fatalities is the fires come from household fires.

[00:00:32] Wojciech Wegrzynski: But we don't get to talk that much about them. I mean,

[00:00:36] Wojciech Wegrzynski: even if you look at this podcast is episode 59, and I guess this is the first one really dedicated, fully to residential fires.

[00:00:43] Wojciech Wegrzynski: I mean, podcast because there's obviously a bias. Uh, presentation of the fire science view through my eyes, but still it's a presentation. And there, there is no accident in that residential fires. We're not here so much. Because it's not an area that would focus so [00:01:00] many researchers over the world, but that this research it is, it. It is researched by great people. And I have some of the best of them today in this show to talk about this important.

[00:01:10] Wojciech Wegrzynski: Issue. My guest today are Dan Madrzykowski from UL Fire Safety Research Institute, legend of the field of, firefighters research and residential fire safety. And I was quite lucky because Dan had a nice guest hosted at his home and that there was a professor Charlie Fleischmann from University of Canterbury. So actually the got the chance to talk to them both.

[00:01:33] Wojciech Wegrzynski: About the issues related to how the fire environment of homes has changed over the years. What are the problems now from the perspective of homeowner? And also from the perspective of the firefighter, I hope it will be interesting to you and there's. All the things that. We need to consider thinking about residential fire safety. And I guess many learnings of this episode will go to all our [00:02:00] areas of fire safety. As we touch just a lot of fundamental fire physics with lots of great examples, brought to you by some of the great signs of fire safety. So.

[00:02:10] Wojciech Wegrzynski: without further ado, let's spin the intro and jump into the episode. hello everybody. And welcome to Fire Science Show. , today's the father day and, I've received a gift, uh, instead of one legend, I got two.

[00:02:44] Wojciech Wegrzynski: So please , let me introduce my today's guest. Uh, first, UL Fire Safety Research Institute, Dan Madrzykowski it's such a huge pleasure to have you in the show.

[00:02:56] Dan Madrzykowski: thank you for the invitation, looking forward to having our discussion.

[00:02:59] Wojciech Wegrzynski: [00:03:00] absolutely thrilled for you to become the part of the show and, and a surprise guest, but very, very welcome. old friend from Canterbury professor Charlie Fleischmann Cey. Hey, how are you?

[00:03:11] Charlie Fleischman: Thanks for having me.

[00:03:13] Dan Madrzykowski: I'm just

[00:03:13] Dan Madrzykowski: sort

[00:03:14] Wojciech Wegrzynski: that's okay. You can hang around in here. I mean, if you were home, we would have a podcast recording under which the sun does not set, but that's a very,

[00:03:22] Dan Madrzykowski: of a hanger on

[00:03:22] Wojciech Wegrzynski: nice, addition and actually, uh, your knowledge fits perfectly to the topic.

[00:03:28] Wojciech Wegrzynski: topic is residential fire safety. So first, lets me, build up the need for this particular podcast episode. ago, I had interviewed professor Babrauskas in the podcast and as one of the key, um, missing points in fire science, he mentioned, unsufficient research on residential fire safety and residential fires and, all the things associated with that.

[00:03:51] Wojciech Wegrzynski: And I thought, well, there's UL doing a lot of research on that. So I need to tap into UL mind. And, and Dan is like, [00:04:00] number one guy there doing residential home, fire safety. I know it, it is important for you guys, but, uh, I would love to understand why it is important for UL. So, so Dan, maybe you could, a good starting point.

[00:04:13] Wojciech Wegrzynski: Tell me why residential fire safety is such an important part of the UL mission. Why do you guys research it so

[00:04:20] Dan Madrzykowski: Well in the Us, uh, based on our data, um, most of the fire fatalities. Occur in homes. they occur where people should feel the safest. So approximately 80 to 85% of the fire fatalities in the us occur in people's homes and, could be in apartment buildings, townhouses, or single family homes. so that that's a big driver.

[00:04:46] Dan Madrzykowski: uh, I listen to Vito's podcast and, Vito's not wrong in terms of. You know, where some of the, where we're putting a lot of effort, there's a lot of research going into, digital twins of buildings as, uh, as [00:05:00] Charlie and I were discussing and, and all this sort of thing. And it's basically being focused on occupancies where currently we don't really have a high fire loss problem.

[00:05:10] Dan Madrzykowski: they're already covered by sprinklers. good passive fire protect. in many cases, active fire protection in terms of smoke control and, and automatic door closers and things like that. So, you know, do we really need more research and artificial intelligence to help us there? and the real problem is we have a very large housing stock.

[00:05:33] Dan Madrzykowski: What can we do if we're gonna use a technology, what can we do to retrofit that technology? Or are we better suited to make the occupants smarter, , to give them better information on what they could do, how they could protect themselves? do we work on prevention? Do we work on self rescue?

[00:05:51] Dan Madrzykowski: how can we help the fire service be more efficient with today's fire environment. So. certainly more can be done in that area. We can always [00:06:00] use better data in what's causing the fires and, how the fires are, occurring, uh, again, to kind of track that down. we are getting some data and the data we're currently getting, shows us that people charging lithium ion batteries in their homes is becoming a, uh, a growing hazard.

[00:06:20] Dan Madrzykowski: Whether it's, uh, charging, batteries that were parts of, tools or whether it's charging E scooters or e-bikes, uh, we're seeing a trend in the us, uh, where those fires are happening more and more often.

[00:06:33] Wojciech Wegrzynski: Wow. I was, you know, preparing to this episode, I was thinking a lot about it. Like. It is in a one way, evident, like, no matter what part of world you look there, that the statistics would say the same, the house is the most likely place you die in a fire Charlie is the same in, in New Zealand, I

[00:06:49] Dan Madrzykowski: If I, as

[00:06:50] Charlie Fleischman: far as I know in every developed, I would say almost every country that it's in,

[00:06:54] Dan Madrzykowski: it's in their own home.

[00:06:56] Wojciech Wegrzynski: And we also have the problem of, you know, social inequality. And [00:07:00] I had Danielle Antonellis from Kindling in the episode, they're dealing a lot with like things like informal settlements, but you don't have to go to informal settlements to see the issue that some people who are, under underprivileged, they, they obviously are often associated with a higher fire risk.

[00:07:15] Wojciech Wegrzynski: So there is an obvious. area in terms of residential fires. And if you think about it, why do we research like tunnels or skyscrapers? think it is well connected to the fact that we have real means touch these items. Like if I do research on tunnels and it turns to be a part of a code, the tunnels will be built to that code.

[00:07:39] Wojciech Wegrzynski: And I have, like, I have a direct link between my research and the outcome in terms of safety, even if it is a small, incremental improvement of safety of facility that was safe already. if you think about residential homes, It is so hard. It like, it is so hard to have an impact between we [00:08:00] researchers do not have a direct link peoples who built houses.

[00:08:04] Wojciech Wegrzynski: it is very difficult to. Go and put any prescriptive or performance based rule out there that would influence the way how people build, because it's perceived as their freedom to build, uh, in Poland. It is like that in us, the country of, freedom and amendments, I guess it, it is , it is, it must be the same.

[00:08:26] Wojciech Wegrzynski: I would not, uh, believe it's otherwise. So. The number one reason. I, I think it is the lack of this. Feeling that I can really change things. And, and you guys in new all, you've been doing that for 30 years, so maybe you have a pathways. let's just give it the structure. Right? I, there would be two places.

[00:08:45] Wojciech Wegrzynski: I distinguish one that being the homeowner and the person who's most likely to die in an event of a fire in my home. And second, the firefighter perspective, which let's talk in the second part of the episode, how to deal with the modern challenges of modern housing and [00:09:00] residential. From the perspective of firemen.

[00:09:02] Wojciech Wegrzynski: So, so reaching owners, like, is there a way to do it? Do you, do you guys have a, a key to do it?

[00:09:08] Dan Madrzykowski: I mean, we're, we're trying to use, Our social media outlets, whether it's Facebook or Twitter or webpage or Instagram, and we've developed some, uh, I guess you'd call them public service announcements if you will, to generate some awareness. So one of the things that we did 10 years ago, and we recently redid it, , was a comparison of natural fuels burning in a room versus. Everyday fuels that we have today. , so comparing a sofa that has, uh, cotton upholstery with, uh, steel Springs in the cushions and things like that versus a modern sofa or a current day sofa, if you will. And when I say current day, the construct, these started to come into the marketplace in large numbers in the lates, in the seventies, eighties, nineties.

[00:09:57] Dan Madrzykowski: So they've been around almost 50 [00:10:00] years. Uh, but the polyurethane foam, uh, the construction methods continue to evolve. the foam can get less desne but still be resilient and very useful and whatnot. , so you can have a sofa that weighs, , on the order of, you know, maybe 43 kilograms or so, roughly a hundred pounds.

[00:10:19] Dan Madrzykowski: And, it can give off a peak heat release rate in the range of four to five. Megawat. And it can generate that peak heat release rate in about three minutes. So if you have that, , in a residential home and, uh, you've got ventilation to it through open windows or open door, , that means that that can, generate a post flashover environment or flash over a room in that home, in that same kind of timeframe, less, three to five minutes kind of timeframe.

[00:10:45] Dan Madrzykowski: So, um, That's sort of a big change. If you look at how the cotton sofa burns, when it's ignited with an open flame, it hits a peak heat release rate of maybe 300 kilowats and it burns for an hour. and if it [00:11:00] can generate enough energy to ignite other things in the room to generate a flashover, that process from what we've seen for the four or five times that we've done, it takes on the order of, 25 minutes to, 40 minutes.

[00:11:13] Dan Madrzykowski: so the, if the firefighters show up to that fire, they have more time to respond to it. , certainly, and that fire is going to be less reactive to the introduction of extra oxygen, because it's not gonna be as vent limited or fuel rich perhaps, , still could be post flashover, but again, it, it seems like a friendlier fire, if you will, , in terms of, how it responds.

[00:11:38] Dan Madrzykowski: people moving about people, leaving people, having time to leave, and then the fires were, uh, tactics to it. So what we have in our homes has changed pretty dramatically, over time. Um, and so we've been trying to point that out to homeowners.

[00:11:53] Wojciech Wegrzynski: and that is with, with this public demonstration tool that you're driving on a truck and, and showing like this old house and [00:12:00] new new house compartments and, By showing the images like, which are very visual, very like with the timer. I, I saw there there's videos on YouTube.

[00:12:08] Wojciech Wegrzynski: They're great. You, can truly show, okay. This is three minutes into the fire. Look, this sofa on the left is belly burning on the right. You have a raging Inferno in your house. So is this message reaching the, the public?

[00:12:20] Dan Madrzykowski: I think that people are still surprised, uh, at how fast a fire can grow in their home. so I, it is having an impact. It is having an effect. Uh, then we are trying to give them actionable items. Now,

[00:12:34] Wojciech Wegrzynski: Yeah.

[00:12:34] Dan Madrzykowski: some people. Have the means or the ability to go out and buy smoke alarms. So that is certainly an important message to get that early warning, uh, so that you you can leave.

[00:12:45] Dan Madrzykowski: I thought it was, , interesting commentary from Vito that he was remembering bud Levin and, and John Bryan of course, and saying, yeah, the initial response of people is not to leave, but to figure out why the smoke alarm's going off [00:13:00] right. In many cases going toward the fire. , so that's gotta be accounted for, , but one of the messages, something that is actionable, for everybody, uh, if they're, you know, mobile and can move around and that's closing the door to isolate, if they can't get out of the house, if they can't make a safe.

[00:13:17] Dan Madrzykowski: , there may be a place where they could protect themselves in the home, protect themselves from heat, from smoke, from toxic gas, by isolating themselves from the flow path and give the firefighters time to come and rescue them.

[00:13:30] Wojciech Wegrzynski: So you're actually framing a very complex and sophisticated research into design fires, into human response, into actionable items, like understand that, the environment is completely different than. You may have had in your had before that, that there is simple items like smoke sensor that can truly change the, your chances.

[00:13:52] Wojciech Wegrzynski: And, there's simple things you can do, like closing the doors that will completely seal. Or change the outcomes of the [00:14:00] fire. that's brilliant because these are things that you can work on. , you've mentioned, I, I love how you immediately went into burning items because that's what our as fire scientists do.

[00:14:11] Wojciech Wegrzynski: the sofa example is great, but Charlie, maybe you can give me the number two worst item at your house. That's that has changed over 30 years.

[00:14:20] Charlie Fleischman: well, I don't think it's changed over 30 years, but if you look at the statistics, um, a lot of fires start in kitchen.

[00:14:27] Wojciech Wegrzynski: Yeah.

[00:14:28] Charlie Fleischman: and I mean, in the New Zealand example, they ran a, a campaign. And again, a lot of it's about educating people, but they found that sort of these young adult males were actually had statistically a greater, I guess, or a disproportionate number of fatalities.

[00:14:46] Charlie Fleischman: And that was they'd come home at night, often having been out and they would put on. They're chip panted, , to deep fry, French fries or chips as they call 'em in New Zealand and they'd have a kitchen fire. So beyond the [00:15:00] furniture, another area where I think we could potentially make some gains is looking at dealing with kitchen fires.

[00:15:07] Charlie Fleischman: And I know NIST has been doing some studies in that area. And it's another area where I think we need to focus on is coming up with creative ways. Possibly extinguishment, but that's a bit, there's all sorts of issues around that, but the kitchen fire is another area. I think

[00:15:24] Wojciech Wegrzynski: And, how about this, fires that are occur when you are not supervising? Like, I would guess kitchen. Fire. Okay. That's, that's a crazy idea of not supervising your pan on, but it happened. It actually happened to me once.

[00:15:36] Dan Madrzykowski: we need to spend some time focusing on yeah.

[00:15:36] Wojciech Wegrzynski: didn't transferring to big fire, but I, I confirm it's not very hard to set your band on fire.

[00:15:42] Wojciech Wegrzynski: However, there are things happening in your house when. UN supervising them, like then before mentioned Lithion batteries. That is an excellent example of how the world is changing because like 10, 20 years ago I would be charging my Nokia phone and, I probably could destroy a fire, throwing it [00:16:00] with, the Noone.

[00:16:01] Wojciech Wegrzynski: It was indestructible and didn't really burn. Then. Uh, I was charging my laptops and. It's a bigger threat. Now people are their scooters at home or much bigger battery items. So do you see any other like changes which need. Immediate research on safety. I, I'm not sure. I'm, I'm pretty scared about, photovoltaics too.

[00:16:23] Wojciech Wegrzynski: And I don't mean the panels necessarily the panels , are a separate item, but, uh, you know, the, the energy must be transported by wires and there's like quite high power electrical unions, like transformers and, uh, frequency, inverters, and all these sophisticated high power, energetic devices.

[00:16:43] Wojciech Wegrzynski: Suddenly put in your house because you have a small power plant. So maybe you have another example of this

[00:16:49] Dan Madrzykowski: I mean, just a, similar example, but just to show how relevant it is, I guess in compounding it is, , you spoke with Gavin about the, uh, exposures on the [00:17:00] fire ground. And, one of the projects that we have working right now is looking at post fire exposures to fire investigators. So this week, uh, we've had.

[00:17:11] Dan Madrzykowski: Our industrial hygienist that we work with from UL, out in the field, traveling with the LA county fire investigators and actually taking measurements at fire scenes, uh, that they're working at to sort of get the ground truth, to see if the, Work that we do in the lab or in our buildings that we purposely burn and then monitor for five days, post fire.

[00:17:34] Dan Madrzykowski: Are we catching the right things? Are we replicating reality enough?

[00:17:38] Wojciech Wegrzynski: Hm.

[00:17:39] Dan Madrzykowski: Uh, the investigators that we work with, one of their, observations or complaints, if you will, is that your test houses are too clean, right? They don't have enough junk. They don't have enough debris. So is there other chemicals hiding in the debris or does it.

[00:17:54] Dan Madrzykowski: Hold the gases or the hazard longer. And so that's why we're going out in the field to sort of get some ground [00:18:00] truth. And just this week, they went to a fire where someone was charging a ECU and a e-bike off a single extension cord. the cord overheated caught fire and burned the garage down and the garage contained an electric vehicle car.

[00:18:16] Dan Madrzykowski: As well, so here they had these three, fairly expensive battery powered modes of transportation. And, you know, I don't know for sure. I'm guessing that, they probably had a couple dollar extension cord

[00:18:30] Wojciech Wegrzynski: mm-hmm

[00:18:30] Dan Madrzykowski: and that was the weak link for them. So, there may be other messaging that needs to get out.

[00:18:35] Dan Madrzykowski: I mean, certainly, uh, one manufacturer in the United States. Uh, issued a, a, uh, alert to anybody that owns their vehicles, that they should be electric vehicles, that they should be charging them outside and not charging them in their garage. , there are signs being put up on like, parking garages that those vehicles are not being allowed to be charged there.

[00:18:57] Dan Madrzykowski: Uh, those kind of things. So, uh, there's [00:19:00] certainly a lot of response, a lot of work to do. the one thing about the residential environment as you pointed out, because in some ways of the lack of, , codes in that you don't need to de develop things for a fire rated assembly for a wall or a floor or things like that.

[00:19:16] Dan Madrzykowski: , the amount of new, construction methods and new materials that are being. In some cases now very limited, but we're starting to see the use of plastic in support structures, , for residential homes. And, they're applying some protection to it, but again, it doesn't really have to go through any kind of testing because it doesn't have to be a rated assembly.

[00:19:39] Dan Madrzykowski: It just has to be demonstrated that it can hold the load. And, these are the kind of things that kind of tend. Sort of tend to creep up on society, right? nobody, it wasn't announced that this is gonna happen. And then it just sort of happens then over time, the next thing you know, there's trouble and, uh, we've had some things happen [00:20:00] even with, uh, well intended, , fire protection type of items where, , in the us, maybe 30 years ago, people want to introduce fire retardant, ply.

[00:20:10] Dan Madrzykowski: In the construction of homes, especially in the use for roof decking in ATS. And, uh, what they found was that the heat in the attic and the combination of the chemicals in the, , fire retardant, caused the plywood to decay. And so after five or 10 years, the plywood no longer was, had its structural integrity and had to be replaced.

[00:20:31] Dan Madrzykowski: There was a use of certain kinds of plastics. , I think it was poly blings, maybe. Sprinkler systems. And then they've had a lot of cracking and leakage. And as a result, then sprinkler systems kind of got a bad, reputation that, oh, this is just gonna cause leakage in my house and things like that. So it's, before we introduce new technologies, I think there's some responsibility, to have them, investigated or checked out to make sure [00:21:00] that there aren't unintended consequences.

[00:21:02] Wojciech Wegrzynski: Yeah, I had this episode, uh, one year anniversary episode of the podcast when I said the number one skill is communication. And by communication, I also mean listening to others. And this is the exact thing. Like if you don't listen to users, if you don't use listen to their needs and you just deliver a fire safety system, that in the end leaks , is annoying or loses it's it's characteristics, It's not gonna work and it's gonna get bad reputation and it's gonna not gonna be used at all.

[00:21:30] Wojciech Wegrzynski: when you say about this, this plastic and field walls, believe they have absolutely. UN earthly, thermal insulation statistics. Like they, these things are like magic. When you only think in like U factor or, or whatever else you use to demine how warm your, your house is. But if you thought three minute flashover is bad, wait for the five minute collapse, like seriously. this is , the direction and, Charlie to you [00:22:00] about , the physics of fires and compartments, like in Poland for the last 20 years, we have this trend of plastic windows, , sealed out houses where we're turning away from that now into, into introducing leakages, but still we make our homes, off the external environment.

[00:22:19] Wojciech Wegrzynski: what I understand, changes the

[00:22:21] Charlie Fleischman: they're starting to do it in New Zealand, but they got it out of Europe with the passive houses and sealing those up. There's all sorts of energy advantages. But as Dan said, we have unintended consequences of any engineering thing we do potentially. And we have to look for that.

[00:22:36] Charlie Fleischman: we are trying all over the world to make, More energy, efficient building. Part of that is to reduce the leakage we have out. And, but as we do that, we have the pressures go up, and there's been a number of studies, you know, that we talked about looking at what the effect of that is.

[00:22:54] Charlie Fleischman: , but we haven't really started to look at what that does even to the fire physics. And what [00:23:00] impact that may have on firefighters. You know, there's that classic case where the firefighters were trapped inside because of an over pressure. but you know, there's things there that we still need to, I think, explore, but it's a matter of finding the time and the priorities and.

[00:23:15] Charlie Fleischman: And you mentioned here, the human side of it in terms of trying to, educate the public, change their behavior potentially on charging batteries. But we have to find those other issues there that, um,

[00:23:27] Dan Madrzykowski: we haven't explored.

[00:23:29] Wojciech Wegrzynski: I think by introducing some of these passive technologies, we go out of proportion. You know, we are gaining very little in terms of insulation of the house and we're losing so much in terms of the fire safety the building. I also wonder, like, to what extent. Higher insulation of the walls.

[00:23:47] Wojciech Wegrzynski: I mean, if you go MQH relation or anything, you immediately see the of better insulated, compartment to the time of flashover or, in general, the, the temperatures you reach in fires, [00:24:00] you, mean, you install the fires, so you keep the energy inside instead, instead of venting. It out. And I, I guess, as we may transition to the, firefighters, erritory this like ventilation aspects of house fires or household fires, residential fires is also probably number one thing for considered by firefighters.

[00:24:20] Wojciech Wegrzynski: Right. And, Uh, did the environment change in the last like 30 years? how the ventilation looks in residential houses and what firefighters should, adjust their tactics for?

[00:24:32] Dan Madrzykowski: And certainly the, uh, the homes have become, more fuel rich, uh, in terms of the energy content, the synthetics have, uh, heats of combustion that are, one and a half, uh, perhaps, uh, two or two times or more that, of, uh, some of the natural materials like wooden cotton, , So that's, uh, that's a issue, as we've been pointing out for sustainability reasons and energy conservation, uh, the houses have become [00:25:00] more tightly insulated, better windows.

[00:25:02] Dan Madrzykowski: So the windows don't, Fail due to fire as easily, they take require more energy to auto vent if you will, , than they did in the past than a single pane window would, , fail the, dual pain windows, take more energy. Uh, so there's a lot of different, um, construction features that, uh, change how the fire grows.

[00:25:23] Dan Madrzykowski: As also, the hazard inside the home for anyone that's trapped and further how the fire presents itself when the fire department arrives a, uh, ventilation limited fire, firefighters hadn't been taught about that until maybe 10 years ago. researchers knew it certainly, fire protection engineers knew it, but, the.

[00:25:44] Dan Madrzykowski: Firefighters were only familiar with the, uh, traditional fuel limited fire growth model, if you will, , fuel controlled, uh, they didn't understand, the ventilation controlled model and it is different and it presents itself different ways. [00:26:00] So the firefighters might show up on a house with the doors and windows closed and nothing showing at the time they show up, five minutes earlier, the fire might have been in a growth stage.

[00:26:10] Dan Madrzykowski: And it was pushing smoke around every leakage around a door or a window because the pressure built up in the house, but then it went into an oxygen depleted the case stage, the heat release rate dropped the temperature. The gas is inside the house decreased. And as a result, the pressure inside the house decreased to the point where the house is under, negative pressure relative to atmospheric conditions.

[00:26:34] Dan Madrzykowski: And so it's actually sucking air in and not showing any smoke. Or on the opposite side of that coin, the ventilation limited fire could be presenting itself as flames coming out of a door or a window. So this has, uh, been a big education process, for the fire service to get that understanding and to understand that also if they have flames out a window, that doesn't mean that there's flames very deep in that structure.

[00:26:59] Dan Madrzykowski: [00:27:00] Because it's too fuel rich. And in terms of a survivable space in that structure, especially if people are, protecting themselves by closing a door, they need to get in there and search. And then how do we help them search, uh, recent work by, uh, Keith Stakes and Craig predominantly the whole team, but, uh, they're, they're the principal leaders of that research.

[00:27:22] Dan Madrzykowski: Is that, you know, getting water on the fire quickly and searching concurrently with that seems to be the best practice. Uh, so there's a lot to learn and understand about how to change the hazard throughout the house as soon as possible. And I know it shouldn't be surprising, but the use of water is a big key to that because there have been concerns in the past.

[00:27:44] Dan Madrzykowski: Potentially, if the water wasn't used efficiently or effectively, you could make conditions worse and there is some truth to that. So then we need to take that next step and say, well, how do we make sure that we're making efficient use of the water? And, I know in, in Poland [00:28:00] recently they built one of the, fire hose, props, fire hose, mechanics props, Keith, stakes evolve that and develop that.

[00:28:09] Dan Madrzykowski: And, as we go around the United States and they're building them and we, uh, help people learn how to use them, it's amazing. the quick takeaway and sort of the aha moments that people are having when, they understand that the significant difference it could make in not only your nozzle choice, but how you decide to move that Nozz.

[00:28:30] Dan Madrzykowski: And if you wanna make pressure in front of you and push, you could do one way. And if you don't wanna push or disturb the environment and just ha introduce a broken stream in the room for maximizing cooling, you handle the nozzle a different way. And I think this is. This is a big step forward, I think, for the us and this isn't to say that firefighters didn't know this before, but I just think it's one of those issues where, , the senior people in the fire service, , the senior man, the barn boss, [00:29:00] whatever you wanna call them, there aren't as many of those people around to share that knowledge anymore.

[00:29:05] Dan Madrzykowski: So I think it's neat. We have an opportunity with data behind us to, to measure in train, to measure where the water's going, that we can help share those lessons, perhaps on a broader scale, , through the internet, through our webpage FSRI.org, where we have, , lesson plans and videos , of using this prop as well as how to build the.

[00:29:29] Dan Madrzykowski: but it, also the face to face, uh, regional meetings around the country are very important. And

[00:29:35] Wojciech Wegrzynski: Yeah.

[00:29:35] Dan Madrzykowski: the fact that it's, uh, getting to Europe, and people are, are utilizing it in Europe and we get, we're getting great feedback from that, that that's fantastic.

[00:29:45] Wojciech Wegrzynski: Okay. because my listenership is predominantly fire safety engineers, and they have no idea about what you mean with the water hose prop. I'll I'll quickly explain because I found it concept fascinating We, we spend so much time, you know, solving this issues with [00:30:00] buildings that we we've talked in the entry to the episode, but you're touching here a very simple problem, how to push water into buildings.

[00:30:08] Wojciech Wegrzynski: So it. Reaches the place you want it to reach. And the water bounces of windows, bounces of walls, bounces of ceilings. And that's one effect. The second is that when you push water, you are pushing air with it. So you can push water and are outside. You can push water and air inside. You actually control that.

[00:30:28] Wojciech Wegrzynski: And, the prop that Dan is mentioning is like literally, uh, compartment, where you can play with water, a corridor, a corner, bounce water of things, try to learn how to operate it in the most efficient way. So it reaches what you want. And. You know, the cell phone game, everyone played a few years ago, angry birds, where you had to bounce the bird out of out things that's the same thing.

[00:30:54] Wojciech Wegrzynski: pretty much maybe you should, should make a video game done the efficient, [00:31:00] firefighter or something where people have to learn that that would be a very efficient way to, to teach people that, but this is this part of. You know, knowledge experience that we need first to.

[00:31:12] Wojciech Wegrzynski: We have to understand like by Craig and colleagues from UL. This is giving the physics background, or why is that important? Like they've solved or maybe they are solving the ultimate question is early water better or worse for the fire outcomes. Based on that knowledge, when they have the answer, the scientific answer to the question, they can train people on how to do that efficiently to reach their objectives.

[00:31:39] Wojciech Wegrzynski: So this is the brilliant you, you know, see, this is the missing point I've mentioned in the beginning of the episode, the missing link between the researcher and the outcomes. And, I find it, fascinating that you guys are doing the research and you're going further to spread the knowledge.

[00:31:54] Wojciech Wegrzynski: Link the videos to this prop training, in the show notes. So anyone can take a look. And this is [00:32:00] really interesting to see what are the on the ground problems firefighters are battling with, or what, what are the on ground issues in firefighting? Um, you've also also mentioned about this. physics of the environment in the fire that are occurring may be unnoticed by the firemen.

[00:32:19] Wojciech Wegrzynski: When they arrive, it can be in a phase where it'll already flashed over and, and oxygen start or something, and they may not know that. , so I, I think, the number one, if you think fire safety engineering education, there is this plot with temperature rising are this there's flash over there's that's if you did statistic, that's probably the plot.

[00:32:39] Wojciech Wegrzynski: Everyone sees the most during their education and it doesn't tell a full story. It doesn't tell a quarter of a story. So I kind of hate it. And, with the thing you you've said, it leads to some very. dangerous. Um, you've used the word in the, in the green room, pressure events or pressure, um,

[00:32:59] Dan Madrzykowski: Over [00:33:00] pressure.

[00:33:00] Wojciech Wegrzynski: over pressure events.

[00:33:02] Wojciech Wegrzynski: Yeah, exactly. And, Charlie, I remember your name in the nineties with backdrops and, and explosions, so, so it's. I've asked you, what are you doing in the us? And you said, smoke explosion. So, ah, I need to talk about that, So, so how did the environment in the residential housing change promote this or? Um,

[00:33:21] Dan Madrzykowski: What you talked

[00:33:22] Charlie Fleischman: about the energy, you know, change improvements and sealing the building on, I mean, if you think of it are what I refer to as our typical. Model or, , vision of a fire is, as you said, you know, fire grows, flashes over, you get flames out the openings, but, you know, and we break windows and that sort of thing, but now we're going with multi-pay low E coatings, that delay all of that.

[00:33:49] Charlie Fleischman: so now we've got these semi sealed boxes that we have a fire in. And, Dan mentioned earlier about you get, you know, the fire grow. Maybe gets close to [00:34:00] flashover. Maybe it gets there locally, but then runs out of air. So then somebody, the fire service comes in, opens a door and, to a certain extent, their knowledge is probably is somewhat as far behind as ours is, you know, fire engineers are still sort of stuck in this typical fire growth, but we're now saying that it is very different and that's what this smoke explosion is sort of starting to.

[00:34:25] Charlie Fleischman: try to understand what happens in these boxes, where we have severely ventilation, limited conditions, but then you bring the ventilation with the fire service and you've got a potentially very dangerous situation. You ha you know, you can have, this unburned fuel sitting there, you bring the oxygen with you one way or another.

[00:34:47] Charlie Fleischman: That's your backdraft sort of thing, but we're seeing where maybe somebody hasn't opened it up, you know, and the place just blows up. Or in some cases you'll end up with, you know, a large building going the [00:35:00] fire's at one end and it blows up at the other end. So it we're trying to understand that what I would say, atypical fire growth things.

[00:35:08] Charlie Fleischman: We don't see all that often. Although I do wonder whether with our changes to buildings, more energy efficient, better sealed, low E coatings and everything else. If we're gonna see an increase in the, these events as we go forward. So that's why we're trying to

[00:35:23] Dan Madrzykowski: understand it.

[00:35:25] Wojciech Wegrzynski: Yeah. To what extent the traditional fire becomes the exotic fire and

[00:35:29] Dan Madrzykowski: Mm-hmm.

[00:35:29] Wojciech Wegrzynski: the exotic fires become the traditional fires. And that's, uh, that's a hell of a challenge. and from your experience, is there. Do the usual, things to read out this pressure phenomen, I've been taught that if you see smoke pulsating, touch the, no, is it hot or not?

[00:35:45] Wojciech Wegrzynski: I'm not a firefighter. So, so please, excuse me if I'm dangerous stuff, but, do, do you see these things work or is it even more exotic and more unexpected than before?

[00:35:56] Dan Madrzykowski: Wow. That's. I mean,

[00:35:57] Charlie Fleischman: we do see the pulsing, you know, and in fact, that's one [00:36:00] of the things that we look for in the experiments in these exploratory work, and you see it happen, but. S, you know, and we think we kind of understand the physics of that, but then you start seeing it in conditions that you don't necessarily understand.

[00:36:13] Charlie Fleischman: And so we're just, we're trying to see if those old indicators actually ever really existed. Okay. And there's some evidence that they do, you know, the pulsing has been seen in a number of cases. the hot doorknob has been something that people have talked about for years, but there's all sorts of conditions that could lead to that.

[00:36:32] Charlie Fleischman: but it's, there's a lot, we don't understand. And these old, I guess what I would call old wise tales, we're trying to see whether or not they're they're real. And one of the ways we're doing that is to work toward being able to recreate these events so that we can then start to ask those questions, cuz we need to do the researchers seems to be a number of different conditions that can happen.

[00:36:57] Charlie Fleischman: and. We're just, you know, at, [00:37:00] at this point, trying to understand, cause I think the most common is the fire sort of goes into a state, may almost even burn out and it becomes a relatively minor event, but we're seeing in a certain number of cases where we get what are very horrific events, of rapid release of energy, whether that's just a big push of smoke or whether it ends up being a smoke explosion where the building appears to.

[00:37:26] Charlie Fleischman: Essentially explode itself or is it something like a back draft where the firefighters have changed the ventilation and they get stuck because they've gotten into the building when this thing lets go. I mean, YouTube is full of a number of videos that you can see. The problem is all you see is one side of the building.

[00:37:44] Charlie Fleischman: It's a short slice. You have no details about the building, how it was built. It. I mean, some of these are old buildings, so they've been. remodeled or renovated and that sort of thing. And we're sort of behind. Cause by the time it hits [00:38:00] YouTube, it's all over the building's not there. We don't get an opportunity to look at it and understand.

[00:38:06] Wojciech Wegrzynski: And do, do you see a dependency in like the terms of, in what compartment or what building it can happen? I remember there was this PhD thesis in Edinburgh, under supervision of Ricky Carvel I think I see the guy was named Wo Cha Lung they, they did, in investigate critical factors when backdrop happens.

[00:38:27] Wojciech Wegrzynski: So, so I wondered like, what you say is not necessarily always backdrop can be some sort of SP exposure, some pressure event. So do you see any type of residential structures that promote it more than others? Or maybe some critical parameters? I always like to think about height as my critical parameter, whatever I build, I build it high now because so, much safer for some reasons.

[00:38:49] Dan Madrzykowski: Well, we did some, work for the national Institute of justice, uh, work on fire patterns. So it's interesting how all these things kind of interlock , and overlay [00:39:00] and, um, we did a two story, uh, house that had a, two story, great room in the rear and a open foyer, two story foyer in the front.

[00:39:09] Dan Madrzykowski: So it's a open floor plan, design home, and then the bedrooms are upstairs and they're compartment and it kind of connected by a bridge that goes between the great room and the, the two story foyer. So starting a fire in the, uh, living room furniture in the rear of the two story. Great. builds a very, rapid, hot gas layer, uh, 16 feet above, or the top of the second floor pushing down.

[00:39:34] Dan Madrzykowski: And then as it pushes down, it acts like a piston and we end up having and a over pressure event at the front door. That was our only opening at that, for that experiment, where for about 90 seconds, we had that door was acting as a full exhaust. because there was enough oxygen within the space to enable that room to transition to flashover, or at least [00:40:00] almost through flashover, if you will, before it runs out of air, in commercials.

[00:40:04] Dan Madrzykowski: So we're seeing that in a residential, uh, big pressure buildups like that if we don't have a lot of ventilation. and then of course, once it's, consumed that air. Uh, that's in the house and now the door is the only, exhaust and intake. We have bidirectional flow. Uh, then we have a condition where now the heat release rate is metered by the amount of air that can get in that doorway, the lower part of that doorway.

[00:40:28] Dan Madrzykowski: So it's still very hazardous inside. Don't get me wrong in terms of temperature, residual temperatures. And uh, low oxygen concentrations and high amounts of co, but the amount of burning that can actually take place is less. So then the next thing, what will happen is if you have, vinyl windows or something like that, then they soften the window pains drop out.

[00:40:48] Dan Madrzykowski: And then we have other flow paths that are set up and the fire can get bigger and bigger and bigger and eventually consume the. but what we're seeing, so that's on a residential scale on a commercial scale. [00:41:00] We're seeing some things like that. in instance, like in LA city where 12 firefighters were burned, flames came out, unit directionally out of a door for about 30 seconds and they traveled, they extended, 20 feet in one of the strip mall experiments that was conducted for our coordinated fire attack project. We had a over pressure event, about three and a half minutes after ignition, where a, uh, large area, with only one ventilation opening transitioned a flashover and pushed smoke about 70 feet horizontally out of that opening. we see some, in a bowling alley in New York, uh, had a fire that again, large open area that resulted in over pressure pushing out.

[00:41:43] Dan Madrzykowski: So we're trying to understand these events as well. there have been a, a couple of smoke explosions, one in Portland, uh, Oregon, fortunately, a couple firefighters, minor injuries only, and one in New York where basically they had a. That was composed of a number of [00:42:00] restaurants at different shops, but it was the size of a city block and they were working on this fire.

[00:42:05] Dan Madrzykowski: The fire had auto vented by the time they got there, it was burning through the roof they had for all intents and purposes, knocked the fire down and then 40 minutes later. Woo. so where was it hiding? What was it doing and, and all that sort of thing. So those are some of the things Charlie and I are trying to get little bit more insight into.

[00:42:25] Dan Madrzykowski: On our, when we could squeeze free time in, on the weekends father's day

[00:42:30] Wojciech Wegrzynski: That's that's a nice hobby. I signed for that, like count me. And, you're scaring the hell out of me with this internal, um, pressure events, because, you know, even for like simple things, like corridor, fire safety, and I'm venturing back to the world that I know, which is like commercial buildings and, buildings equipped with safety systems, you know?

[00:42:51] Wojciech Wegrzynski: How reliant is our strategies for ventilation, the corridors to the fact, if the doors are closed or open or, and what happens in this like [00:43:00] 60 seconds that we assume the doors are still closed. And when you say there may be a pressure event, uh, venting the flames into the corridor because they.

[00:43:09] Wojciech Wegrzynski: Amount of air inside is enough to sustain combustion and, uh, windows are so tight. There's no alternative flow path. That is, that is not something I consider in my design, uh, or safety strategy for the building, for sure. And I appreciate you guys, researching, these aspects of, of fire safety. Okay. I think we're, we're reaching, towards the end of the time allocated for this. I I'm the last thing standing between you and setting fire to some smoke and exploding. It as, I don't, I don't want to, to keep you waiting for that, but I think the world of, of residential fire and the research needs is, is vast and important.

[00:43:53] Wojciech Wegrzynski: And. Maybe you, you have a young message that we could give to like young scientists who would be [00:44:00] like thinking about their, the topics of their and, trying to set food in, fire safety How to push people to do research that is and useful to the wide society even.

[00:44:13] Wojciech Wegrzynski: And, is it worth it, like, do you feel accomplished, Dan by doing exactly that for like the whole of your career? Let's try to push people into this field of research unless you don't recommend them though.

[00:44:25] Dan Madrzykowski: no, no, no, no, no. It's, uh, Uh, certainly, fire research has, you know, been a very attractive career for me. I've had, a lot of opportunities to do, a wide range of things, whether it was, uh, investigating fires in the oil fields of Kuwait or, post earthquake fires in Kobe, Japan, or, now we're looking at building to building fire spread, in the United States.

[00:44:47] Dan Madrzykowski: Things that I think have been categorized as typically, but now maybe we're seeing some events that indicate, uh, maybe wooey has nothing to do with it. It's the houses are really close together and [00:45:00] you get one on fire and there's a wind and you're gonna lose a neighborhood. so you know, a lot of different challenges there, but I think the, the main thing, which is a, core to the, I think the, Fire Safety Research institute philosophy, and part of that is doing research with your stakeholders.

[00:45:18] Dan Madrzykowski: for a lot, a big portion of my career, I was doing research for someone. I was doing research for the fire service, or I was doing research that might help fire protection engineers. But the reality was while I was doing that research, I wasn't talking to any of them nor were any of my leadership. and the big transition point in my career, I think in, in many.

[00:45:43] Dan Madrzykowski: Is when we started to do research with the fire service and talk to them and have them on the fire ground. When we're in Chicago, we're burning a 15 story building and we have 'em. We have a little bit of pizza and a little bit of beer the night before and tell 'em what we're planning to do. And the [00:46:00] chiefs that are gonna be running the crews the next day, how they can help us.

[00:46:03] Dan Madrzykowski: And they didn't talk too much the first night. a little hesitant, not sure what they're getting into with the re the engineers and the scientists, but then after the first day of testing, we did it again and, sat down and over meal and talked a little bit. And then they had a lot of ideas. Well, like, why are you doing this?

[00:46:22] Dan Madrzykowski: Because we would use this stair for evacuation and this stair for suppression. And we wanna, we would do this and this. And then we modified our experiments because the end of the day, We wanna have, data that they can use and they can apply. And I think the same thing is true for homeowners. , the same thing is true for if you're doing work to help fire protection engineers, you need to understand what their needs are.

[00:46:46] Dan Madrzykowski: You need to work with them. And, what you will find is when you start those discussions, uh, that the number of topics that need research. Uh, goes up exponentially and you realize that there's just not enough time. So [00:47:00] one of, one of my other missions is we're trying to grow the size of our staff, um, because we only have so many weekends and, uh, and it's just not enough.

[00:47:09] Dan Madrzykowski: It's just not enough time.

[00:47:11] Dan Madrzykowski: And, um,

[00:47:12] Wojciech Wegrzynski: transition to four day work week. So your weekends are 50% longer. You can work.

[00:47:18] Dan Madrzykowski: But, uh, there's a lot of young people out there in the universities right now, coming outta school. Uh, they've gotten incredible set of talents, uh, in terms of programming and coding and they're learning about fire. And, uh, we're fortunate that through our, fellows program with the university of me, That we can support some of those going through their master's degree.

[00:47:39] Dan Madrzykowski: And now, uh, working on a PhD, uh, we also have, uh, and now's the time when we have our summer students in. and, uh, so it's, it's good to see, the talent that's out there and the passion. And so if we can help grow their passion, for this field of study, then they'll continue on and that's a person that's in it for the next 40 years.

[00:47:58] Dan Madrzykowski: So, uh, that's, that's what [00:48:00] I'm trying to do.

[00:48:01] Wojciech Wegrzynski: And Charlie, the next generation that's growing in Canterbury are, are they going into residential fire safety or you're just pushing them into places where they will earn a lot of money.

[00:48:10] Dan Madrzykowski: Well, I don't wanna be hard on

[00:48:12] Charlie Fleischman: consultants, but if they didn't offer students so many jobs, it'd be easier to get people to go into research and that sort of thing. But I mean, my message to people is, I mean, somebody early on in my career, as I was finishing, he said the job of E every fire engineer is to create more jobs in fire engineering.

[00:48:32] Charlie Fleischman: Cuz the need is there. We just need to get people educated in. But I mean, you've let us through a discussion today and we probably listed 20 topics that out that, that we need to know more about

[00:48:46] Dan Madrzykowski: that we.

[00:48:47] Wojciech Wegrzynski: each could be a fantastic PhD.

[00:48:49] Dan Madrzykowski: Well, and

[00:48:50] Charlie Fleischman: there's probably, I mean, there's thousands out there that can be. and I talk to students, I teach, you know, a first year course of 600 and they talk [00:49:00] about other, you know, I wanna go write apps for phones.

[00:49:03] Charlie Fleischman: I want to go build robots. I wanna do this thing in sustainability. But the thing to tell 'em is fire's not dead. There's a lot. We don't know. And these whole issue of unintended consequences is we make our buildings more energy efficient and everything else. we just need to get the message out there and your listeners are some of our best ambassadors out there.

[00:49:27] Charlie Fleischman: They all know, young people who are thinking about going into something in their field better yet. Talk to 'em when they're, before they start high school so that they start to do the math and the science that they need. A lot of 'em have that. But we just need to guide more people there. We need to get 'em into universities.

[00:49:47] Charlie Fleischman: Cuz as Dan says, it's a very interesting career. There's some hugely interesting topics, but it doesn't appear on most kids' radar. so we need to promote the industry and that comes from all of us, you know, [00:50:00] to get more people in there I learn every day. What I don't know.

[00:50:04] Charlie Fleischman: Okay. And unfortunately that's getting much bigger as I get older

[00:50:08] Dan Madrzykowski: and there's

[00:50:09] Dan Madrzykowski: so

[00:50:10] Wojciech Wegrzynski: is growing quick.

[00:50:11] Dan Madrzykowski: it is,

[00:50:12] Charlie Fleischman: and we just need to get more people into it. And as I say, that's all of our problems. talk to young kids that, you know, and let them, face it. Most of us, if not all of us played with fire as a kid, that's probably the first you know, self-guided experiment that anybody does in their life.

[00:50:32] Charlie Fleischman: And we just need to. I'm sorry to use a pun, reignite their interest in fire to get 'em, to go to university and study it. And then they can go into the research side, because that's an area, you know, we need to

[00:50:46] Dan Madrzykowski: continue to expand.

[00:50:48] Wojciech Wegrzynski: Yeah. I, I also believe strongly in giving back and, do spending time on this podcast is my way of giving back to the community that gave me so much, and, profession that gave me so much. And I also think there's a [00:51:00] lot of engineering companies, you know, there's a thing with, with skilled fire safety engineers, who who've been in 20 years of design.

[00:51:07] Wojciech Wegrzynski: see things differently. You, you can look at the compartments of your house and immediately see some threats that, that people would not see. And I, I believe. In companies, it's great that you are involved in hundreds of commercial projects and so on, but maybe give your employees like 10% of their work week to work on some passion project may be related to changing fire safety of residential housing, employing the knowledge they now have because they're in this very unique place where.

[00:51:36] Wojciech Wegrzynski: It's either them or, or no one in the world will do that because no one has these capabilities. And by this way, giving back, you can make a difference. And it's, I connect this a lot to the mission of fire safety research Institute, like, putting a lot of effort to communicate with stakeholders, to give, to work with them and, and give it back.

[00:51:54] Wojciech Wegrzynski: And also goes to you guys, uh, sitting here on a nice weekend. preparing to, to [00:52:00] burn. How to understand better how we can protect the next one. So I think this is a very nice way to, to finish this out and I'm very thankful for what you guys are doing it. I'm certainly gonna continue what I am doing here.

[00:52:13] Wojciech Wegrzynski: so gentleman, uh, firelighters up and you're free to go and burn that house. Just let me know how it finished, how it ended. Thank you so much for joining the show.

[00:52:25] Dan Madrzykowski: Thanks for having us and, and thank you for your mission here of, uh, having this podcast and, uh, and sharing the information. Thank you.

[00:52:33] Wojciech Wegrzynski: And that's it. Thank you for listening. You've been named the ambassadors of fire science and I'll go in into the world and do your job. Pleasing spider young people to fire safety, change their minds over their future choices and bring us many bright minds into the space of fire safety engineering as possible because we need them. And this episode was all about it, why we need them and how they can make a true difference in the world.

[00:52:58] Wojciech Wegrzynski: In terms of the [00:53:00] takeaways from this episode, I, it was interesting to hear about the fire dynamics in tall residential compartments and how transient evolution of fire changes there. And environment in the first, I mean, there's of the fire. This is something we don't really often consider that much. We often consider the growth of the fire as a gentle event until it reaches flash over

[00:53:21] Wojciech Wegrzynski: And here, Dan has mentioned multiple things that are going to happen in that time. Differences in pressure changes in the flow paths. even smoke explosions to an extent. That's really interesting and something we don't really see in our everyday engineering and maybe we should, that's a, potentially challenging but interesting direction.

[00:53:41] Wojciech Wegrzynski: To go and I'm definitely gonna dig more into that research. And the another takeaway. After the episode, we've spent like five minutes more talking and, we we've agreed that the fire fighters and fire engineers, they love to play with fire and they love to play with water and that's. [00:54:00] Water prop.

[00:54:01] Wojciech Wegrzynski: Training devices really fun. And if you have a chance ever to try play with it. It's a great experience. And actually it's really an interesting experience to play with, with extinguishing tools and see how. you can really apply water to fire, how it changes the fire behavior. It's something very refreshing for a fire engineer.

[00:54:22] Wojciech Wegrzynski: To see how fire is being fought against, because it gives you a completely different view on. How we design passive protection and active protection to. allow for that. for the fighting to take place in the buildings.

[00:54:34] Wojciech Wegrzynski: So, yeah. Thank you for listening to this episode. And next week, next episode is going to be. On.

[00:54:41] Wojciech Wegrzynski: glazing in the fire, something we've talked to in today's episodes as well. So it's going to be a great followup to these episodes. If you've enjoyed this talk. You're going to enjoy the next one for sure. See you then next Wednesday, cheers