Slashdot Mirror
Advances in Fire and Rescue Technology?
He Definitely Didn't Inhale asks: "As anyone could imagine, being trapped inside a burning building would be terrible, but people risk their lives every day to save people stuck in that situation. While fire sprinklers are installed in some buildings they are far from ubiquitous, and also tend to cause plenty of water damage during their use. Some server rooms are isolated and can be filled with an inert gas in the case of a fire, but people - and fire - need oxygen to live. Another idea has recently been patented (USP#6,446,731), whereby a truck mounted high capacity fan is used to remove smoke and heat from burning buildings through the use of an extensible tube. This could make it much easier and safer for firefighters to rescue building occupants and put out the fire. Are any similar technologies or methodologies in use today? What are some design issues that may need to be resolved before this concept can be used safely and effectively? Are there any reasons not to pursue the development of this potentially life-saving idea?" Earlier this year, Ask Slashdot discussed Halon systems. Folks interested in this topic may want to give that previous article a read.
Where have you seen this technique used? This will basically turn the house into a giant blow-torch.
That technique (Positive Pressure Ventilation) is widely used in the fire service, pretty much everywhere in the U.S. It is, as near as I can tell, pretty much ubiquitous. The training materials provided by IFSTA teach PPV, and PPV training materials and equipment are very much in demand in the fire service.
Your point about turning the home into a giant blow-torch does have some validity of course. PPV, when done wrong, CAN have negative consequences. Timing is crucial to do proper PPV. As one of the parent threads pointed out, the idea is to force the smoke and super-heated gases away, clearing a path for the fire crews to advance on the seat of the fire and extinquish it.
Another factor is where the PPV fans are placed. Firefighters are taught to always (when possible) attack a fire from the un-burnt side. What this means, is that when you "push" the fire, whether with PPV fans, or with the air pushing effect of hose-lines with fog nozzles, you push the fire back into territory it's already burned... this is part of the "locate, confine, extinguish" strategy.
If you did the opposite, attacking the fire from the already burned side, you would not want to try and use PPV, or you would indeed be helping to spread the fire into areas that were not yet damaged.
For anybody who's interested, here's a link to some more info: http://www.tempest-edge.com/ppv/
In my experience these fans are usually used to remove smoke from the house after the fire has been extinguished.
That's also a valid use of ventilation fans, although the fans used for negative / exhaust ventilation are usually smaller, electric fans, with less capacity in CFM.
// TODO: Insert Cool Sig
Hee..actually this is in response to the venting truck only. I prolly should have explained that.
Sprinkler Systems ROCK. Haylon (newer chemicals) systems rock. Just don't be stupid when the alarm goes off...you should have plenty time to evacuate or cancel the countdown before the system purges.
Don't even think about fighitng a winning battle with a fire using the hoses provided to you in a building (or a garden hose for that matter). Hoses in a house or building should ONLY be used in a situation where your only means of egress is through a fire (preferably small).
Actually, firefighting techniques can be pretty geeky. New techniques and equipment are being developed by firefighters on a regular basis. Almost all tools were designed by firefighters in response to needs that can't be fulfilled by the tools provided at the time.
If you are interested in learning more, consider volunteering with a fire company. Personal equipment and training are usually free. Some companies provide housing for free to students in exchange for students providing time and service to the company on a daily basis.
The rewards are great! You will be healthier for it, you will meet plenty of life-long friends, and you can't describe the feeling of saving somebody's property and most importantly somebody's life.