Why water is awesome
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- Опубліковано 31 тра 2020
- By understanding how water works to extinguish fires firefighters can use their water almost 6 times more effectively. This video takes a quick look at water and the latent heat exchange.
- Наука та технологія
I learned the transition from ice to liquid to vapor was a "Phase change" and that phase change can be used for moving energy around quite efficiently.
Great
Hey Matt,
These are great videos and explain fire behaviour really well! Explaining water and how it works on the fire explains a lot on how you can use water effectively , would you be doing a video on how class A and B foam work as well? Cheers H
Hi Hannah, Thanks I'm glad you like the videos. Also thats a great idea for a video 👍 It may be a little tricky to film as I generally try not to use fire agency resources like trucks and pumps etc. But I might try to give it a go in the future 🙂
Hey Matt ,
YOU LEFT THE POT ON THE STOVE AGAIN !!!!!
😅
Getting forgetful these days!! 😄🤦♂️
Also very interesting! - a nitpick about the water diag but that is irrelevant to the video message . .
I'm going to say this at the start water takes away the heat from a fire because water cools it
It is interesting as to the effects of the water, but there are some kinds of fire that can not be put off with water! like greek fire, Also I notice the you use the water hose to spread mist in to the heated smoke, but not into the fire itself, Why do you do not use a 2 systems to put that fire off more efficiently? like the water fast mist for the smoke on top and the water at the same time for the fire itself? Maybe I think would be the way to stop both, the source that is the fire and the heated gases on top. What do you think of this idea? Has this been tried? I would love to hear an answer to these questions, please. HM
is the chart correct? Is 10450Joules the same as 100 calories? Isnt it 100 calories to heat 1g of water from 0'c to 100'c
It's been a while since I've looked at that video. But all facts and figures for the videos are referenced from text books, peer reviewd scientific articles or reputable webpages. That said I'll review it when I get the time and make changes if required.
UL, NIST, and FSRI have found time and time again from the studies at UL and the famous Governor's island study that fog streams directed into the overhead are not more effective than a straight stream, and in fact that they are a liability because they entrain so much air.
What do we use to hydraulically ventilate? We use fog streams to do that. So why are we hydraulically ventilating the overhead?? Would you use a PPV fan on the window the fire is venting out of? American fire culture is filled with stories of probies "steam burning" (steam burns dont exist) interior crews with accidental fog streams. This is invariably caused by the convection current created by hydraulically venting the compartment from within, and not stream creation which was a very common myth in america. Aussies and Euros dont roast themselves inside fires because you guys "pencil" the fire stream and do short bursts of fog to aviod turning the compartment into a convection oven. But why do that when you can just let a solid stream rip full bore and have the same extinguishment capability. The fog just Does Not knock the fire down sustainably more than a solid stream does. Even if you think vapor is better, a solid stream directed at the ceiling breaks up into a vapor after impact. Now most of the water does end up on the floor but fun fact, when UL did their water mapping study they found that most of the water in a fog stream also actually makes it to the floor rather than being converted into steam.
Straight stream is simply better for structural firefighting.
Now do we need fog? Absolutely yes, propane and car fires absolutely need a fog. Also there's something to be said about fog for protecting exposures.
Hi. Yep I agree. They really did and continue to do some really awesome work! The point of the video is supposed to be the importance of the latent heat exchange not a discussion about straight streams and diffusion nozzles. I actually try to avoid talking about tactics on this channel as tactics can always change as new research or better methods are developed (the nozzle dabate is a great example). Also I don't think anyone should learn tactics from a random person on the internet. But given your reaction I may have missed the mark. I'll take another look at the video and see if I can do a better job of it 🙂 Cheers, Matt.
@@MattDavis5 Ah gotcha, must have paid to much attention to the illustration.
I must say though, your content is amazing. Went through your whole flashover series, great stuff!