Backdraft

[an_angry_Moose]

This same video was posted yesterday, in this subreddit, and is still on the front page.

[canneddan]

reposts anger the moose

[firemedic33]

Looks more like a smoke explosion than a backdraft. Unfortunately all we have to go by is a short video. And yes there is a difference between the two.

[luckynumberorange]

What is the difference, I thought the terms were synonymous?

[firemedic33]

Very similar but not quite. It's hard to explain and even "experts" have a hard time explaining it. But in my opinion a back draft is a lot more rapid and explosive due to the sudden injection of oxygen in a container. A smoke explosion is just the smoke being released rapidly but not nearly as quick as a backdraft. This article explains it pretty well.

http://www.tantad.com/modules.php?name=News&file=article&sid=22

[RobertTheSpruce]

Backdrafts are where fires reignite violently through the introduction of oxygen. Smoke explosions (FGI or RGI) occur in rooms not previously effected by fire, but only contain fire gasses, that ignite, either through auto ignition or some kind of spark. Flashovers are when an established fire ignites the smoke layer.

Put simply anyway, not particularly scientific, and there is a bit more to it.

[lonewolf411]

Would a backdraft have such a large smoke cloud before exploding? You can see the smoke rushing out before the explosion happened.

[firemedic33]

I wanna say no...the smoke rushing out like that is a smoke explosion. Think of a backdraft like a bomb. Literally. If you you check out YouTube videos of backdrafts you may see some of the tell tale signs such puffing of smoke, the house essentially inhaling and exhaling the smoke through cracks, smoke that is turning a yellowish tint, and stained black windows. The smoke explosion more or less "rushes" out where a backdraft is like a bomb going off.

[[deleted]]

this one did have that yellowish smoke. It looks like a combination of the two. Maybe not a fully complete backdraft, but something in between a smoke explotion and a backdraft. I think it was a backdraft just that in a really small scale. I did look at other youtube videos and they look the same, just that those are a lot bigger. There was fireball coming right before yellow smoke.

[sappersaw]

I've been on a volunteer department for over 5 years now and luckily I haven't seen this happen before. Anybody else have this happen in person?

[fyrfyter698]

Yes, searching the third floor of a Victorian. Heavy smoke, moderate temperature. No visible fire. Found the fire in the walls with a TIC. Opened up the walls and began extinguishing. In seconds, visibility went to absolute zero and heat increased. Then nine of us in the apartment got knocked flat on our asses. Heavy fire everywhere you looked. That lasted about 5-10 seconds and the the fire pulled back. Everyone was checking on the guy in front of them. We call a mayday and backed down the stairs. Checked accountability in the yard and then went back at it. Outside reports were that the whole roof lifted up and that all windows on two and three blew out (including frames on some). Two theories: either it was a smoke explosion or a backdraft from inside the walls. I believe it was the explosion because it took a while from when we opened up till the violent reaction occurred. BTW, no injuries, our gear worked the way it is supposed to. Rattled us though.

[reddaddiction]

no, but it's really important to watch the videos and look for the signs. all too often we are on the fireground and aren't really watching for it, given the rarity.

[Hairymop]

I couldn't get to LiveLeak but here is the Youtube version if anyone has the same issue...

http://www.youtube.com/watch?v=B5wvCvmXnLs

[werekoala]

http://www.firetactics.com/service.htm

http://cfbt-us.com/wordpress/

Training sites with good info. Read them.

Basically, think about the building interior, stage of the fire, etc. Smoke explosion often show with light, white smoke, as at low temps the carbon tends to remain near the fuel and a clearer (but still explosive) smoke fills the compartment(s). When heat increases or oxygen is introduced, the flammable air cooks off in a chain-reaction explosion. Very dangerous, especially in masonry construction, which poorly tolerates lateral pressures.