I've seen a few people on here ask question as to what exactly this is, how it works, and some of those questions were quite recent, so I'll try and explain this in easy terms. What you've got in there is a fire that's been starved of oxygen. They closed off the doors and windows, and the fire soon uses up whatever oxygen was in the air in there. For flames/combustion to occur you need fuel (the wood they have in there), energy (the heat of the fire) and oxygen. No oxygen means no flames - BUT the massive heat and smoke remain, and the smoke is building up. The interior is now at higher pressure than the outside atmosphere due to the heat and smoke build up, which you can see by that smoke venting through whatever cracks there are. You open a door and, as you can see in the video, all that heated gas pours out because there's a high pressure inside, remember? But at some point after you've opened that door, the pressure equalises. Oxygen from the outside can now enter, which is what he refers to when he says "now there's an opening". Once enough oxygen hits that atmosphere all those heated gasses inside can now combust - with the spectacular result you see here. What the instructor is teaching here is looking for and recognising the right "signals" in the smoke in order to realise this room they've simulated here is posing a backdraft risk. Pulsating, dirty white-ish smoke coming out of any small crack is a cardinal sign, often likened to cauliflower or jellyfish in appearance. I hope this helps!
Honestly, I'd argue that a backdraft is more dangerous to firefighters than flashovers albeit this is coming from a non-firefighter. Flashovers are extremely easy to spot and prepare for if you know the signs but backdrafts are borderline completely unpredictable. Also unlike a flashover, there is no way of avoiding a backdraft. A flashover could be avoided if you instantly hit the deck but a backdraft is gonna hit you no matter what.
I would think with a flashover you have immediate ignition the moment air is brought in, where with backdraft it is a low temperature condition where air and smoke freely mix for a time before an explosive ignition through a secondary source.
@@lorddrayvon1426 Backdraught is extremely predictable in most scenarios. If you are aware of the history of the fire (All windows and doors closed, fire been burning for a while) and can see these symptoms like pulsating fire gases from cracks around windows and doors then the danger can be mitigated. As you saw in the video the reaction isn't instantaneous once the compartment becomes ventilated so as long as you are aware that you have a backdraught scenario then you can manage it effectively.
absolutely correct ventilation is key to get rid of the gases and smoke. plus firefighters that may be inside a structure will be able to have possibly some vision being low to the floor as possible doing a search or combating the fire from inside.
@@billdang3953 because it’s so heroic going in and risking your life for an inanimate object. Get them going on medical calls and actually living up to their title of first responder then we’ll talk heroic. Sincerely a paramedic
I was going to say "that would throw a guy a couple hundred feet through a car windshield, killing him instantly" (reference to the Backdraft movie), and i wasnt disappointed.
That's exactly what happened to me when I was getting my charcoal grill ready to cook some steaks. I got the charcoals started and closed the lid thinking I had enough ventilation but nope! Came back outside to check if the charcoals were ready, opened the lid and I had a ball of fire in my face. My hair and eyebrows were smoking. All I seen was orange flames. My daughter was out there at the time when it happened laughing her ass off. 🤣🤣 I never did that again. That shit was scary as hell. Live and learn.😂😂😂
This is behaving just like a bitumen boiler fire when the lid is used to cover it. Same shape / type / colour of smoke. . . only much bigger. Whodathunk?
Read the smoke - it is telling you what is about to happen...and where you don't want to be. When they re-opened the door after letting the pressure build - Smoke is coming out and moving up at a rapid pace....but if you look at the bottom of the opening, you can see smoke going in. Then Whoooosh! Interesting setup they have. It worked very good for this demonstration.
i have new respect for the firefighters here, that building was loud and instantaneous: they never took their eyes off of it, i assume they were ready to hit the deck in a split second to avoid the possible blast
I was expecting a backdraft to occur as soon as that front "window" was opened, but it didn't happen until several seconds later. Can anyone explain the reason? Was outgoing smoke so thick that it was delaying incoming air getting in? Thanks!
I think inside was too oxygen depleted and it took a while for enough oxygen to get back in and mix with the smoke to ignite... if something is too fuel rich it won’t ignite right away.
This could actually be an instance of ventilation induced flashover, which is often mis-labeled as backdraft. A backdraft will almost instantly happen when oxygen is introduced and requires enough oxygen to be introduced to a fire. A backdraft also needs the heat content to be at a level where the oxygen is the only thing needed for the event to happen. A ventilation induced flashover is exactly as Jeff explained, the fire basically resumed development once the door was opened and looks like a backdraft with these conditions once the fire flashes over.
@@MrJoevette05 That's pretty much what a backdraft is, yes. The fire lacks oxygen, so the flames go out, BUT there's still a ton of heat in that room, smoke/gas keeps building up. As soon as you open a door or a window, you add oxygen to the mix, and all of the heated gas that has built up ignites again. And in this case, they gave themselves a little more time. This is basically opening a window to the room - because the gas is under pressure, it expands outward first (pressure inside higher than outside), but as soon as enough gas has escaped and the pressure more or less equalised (the 'gap you can see right before it happens), fresh air comes in, remember it's still super hot in there, and there you go. It happens faster if you open up a larger area - if they had opened the door fully, the backdraft would've happened faster as there is more room for gas exchange to happen. Basically, if you suspect there's a fire behind a closed door or window, DO NOT OPEN IT.
@@dastardlybadger the flame source doesn't go out in a backdraft. After the door is opened, an explosive mixture starts to form until it touches the flame source. A ventilation induced flashover like you're describing isn't about explosive gas mixtures necessarily, just materials above their flame temperature with no oxygen
Cool video, but was anybody else focusing more on wth dude was saying, rather than watching the fire? Dude sounds like he is from deep wood TN or back wood NO! Lmao!
The container is just a tool that’s used to force a backdraft to happen. It teaches the signs of a backdraft situation and helps train firefighters to recognise when this might happen. Meaning they can tackle the fire appropriately, while keeping everyone as safe as possible. Any well established fire that’s been starved of oxygen can/ will do this regardless of where the fire this.
Alright, so in this video they show a backdraft in action, my only question is how do you "fix" the problem without causing a backdraft to happen? Or do you simply wait for the fire to die
A backdraft is a dramatic event caused through rapid re-introduction of oxygen to combustion into an oxygen-depleted environment in a fire; for example, the breaking of a window or opening of a door to an enclosed space. Backdrafts present a serious threat to firefighters. Source: en.wikipedia.org/wiki/Backdraft In the video, they close all the doors to the space, depriving the fire of oxygen. Then they open the door and you can see the lower area is sucking in oxygen. Once the space has enough oxygen, you have a room with an oxygen fuel mix. The fuel is the smoke from the smothered fire which is flammable. In the final moments, that mixture ignites and rapidly burns.
+LTZ VIDEOS. what's happening is when all the hatches are closed the fire dies down to a smolder and cooks the flammable materials making them release their flammable gasses. when a hatch is opened some of said gasses rush out from the pressure, but once the pressure between inside and outside is equal air begins to be drawn in, once the air and the combustable gasses reach an explosive ratio... kaboom.
Wenn der Rauch diese Farbe hat, hälst Du Deinen Popo besser da raus aus der Bude. Solltest Du schon mittendrin sein, sieh zu daß Du schnell rauskommst.
Imagine standing that close and not having on your air respirators. Lmao, what the actual fuck is going on there? Breathing in all that shit and people wonder why firefighters die young...insane.
@@swt2296 They’re out of the smoke but there’s still vapors and gases still emitting from the smoke that you can’t see. Not to mention that smoke off-gases. Doesn’t matter if you’re not “visibly” near it still off-gases to the point you’ll be engulfed by the carcinogens at that proximity
@@mansagarus9226 the point being that everybody on a fireground is not practically viable. I’m always the first one to advocate safety and safe systems of work to include respiratory protection. At a car fire the whole crew doesn’t don BA or entry control officers at a fire don’t and cannot wear BA. Because people not in the risk area should not need respiratory protection which is the point made in Natog. Practically not everyone can be wearing ba and realistically not everyone needs ba. Clean air realistically an area out of smoke. Yes there are vapours but if a gas monitor isn’t detecting them then it’s such an small amount (ppm) then I wouldn’t even worry about it living in a city is probably more detrimental to your health.
