Thread: Ppv!!!!!!

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    Question Ppv!!!!!!

    Can someone explain why PPV is used in attacks. I have heard that some Departments use this tactic to charge a structure before entering and making an attack. To me this sounds way wrong because I don't know anyone around my area that does it, therefore I have never seen it in action. We use PPV but only WELL after the fire is out to clear the structure. I can't find any positives to this tactic except and easy entry. Does anyone use this tactic and can you fill me in on the positives to this tactic?

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    If you have enough people responding to an alarm, you can get your line in and once you get water on the fire and achieve knockdown then you can start the fan to clear the smoke and whlie finishing extingusihment see if it makes any other hot spots light up. I would not start the fan while attack was ongoing and no one else was coming in behind me. When coordinated it works well.

    Positives- gets the building ventilated early, makes secondary search better. Also clears the structure to see if there is any more fire, also may keep smoke damage less to the structure.

    Cons- not paying attention or un-coordinted planning could burn the place to the ground.
    Last edited by Weruj1; 02-04-2004 at 10:54 PM.
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    As weruj said, you have to have plenty of people, but also those people have to be trained very well in this method. If they don't, you will lose the structure. This tactic works very well for many of those that use it, and they will swear by it, but it won't work for everybody.

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    We try to get the PPV going as soon as possible after the initial knockdown. We have had good luck with this method for all the reasons mentioned above. As stated above though, it is very easy to cause more damage if hot spots flare up and go unnoticed.
    Last edited by chriswv3; 02-04-2004 at 10:55 PM.

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    Use of PPV is usually limited to smaller fires, such as room and contents. If ventilation is done properly, the pressure created by the fan helps to remove heat and smoke from the structure, making life much more bearable for the firefighters entering the structure. If a fire is in advanced stages, much more ventilation is required. Most departments accomplish this by taking all the windows (horizontal) once lines are charged, and are ready to advance. Firefighters may also choose to perform vertical ventilation by cutting the roof open over the area of fire in a structure. Conditions, location and size of the fire, and building construction will merit which tactics should be used. The trick to PPV is controlling the ventilation openings. If a structure has to be opened totally, then a PPV fan will not do much more than make a lot of noise. Also, proper placement of a PPV fan is something that I STILL see a lot of fire departments screwing up. Even after proper training, the PPV fan is being set inside the doorway, and not several feet back from it. Not only is this a serious exit hazard, it merely results in the air/smoke/heat circling back out of the doorway, and back into the structure. Just like any other tool on the truck, PPV is great...if used correctly.

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    i have a friend who had some training about using ppv during intial attack. i believe he said the instructor was from utah. anyway from what i gathered, is it can only be used in ''room and content'' fires. and supposedly by starting the ventilation first it starts to cool everything down and snuffs the fire so the attack and or search team can find the fire and anyone trapped inside easier. personally i think it would make the fire flare up even more by doing using ppv right away cause your introducing fresh air, but the way it sounds it will somehow control/blow it out?.

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    i have a friend who had some training about using ppv during intial attack. i believe he said the instructor was from utah. anyway from what i gathered, is it can only be used in ''room and content'' fires. and supposedly by starting the ventilation first it starts to cool everything down and snuffs the fire so the attack and or search team can find the fire and anyone trapped inside easier. personally i think it would make the fire flare up even more by doing using ppv right away cause your introducing fresh air, but the way it sounds it will somehow control/blow it out?.

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    Originally posted by firefighterbeau
    i have a friend who had some training about using ppv during intial attack. i believe he said the instructor was from utah. anyway from what i gathered, is it can only be used in ''room and content'' fires. and supposedly by starting the ventilation first it starts to cool everything down and snuffs the fire so the attack and or search team can find the fire and anyone trapped inside easier. personally i think it would make the fire flare up even more by doing using ppv right away cause your introducing fresh air, but the way it sounds it will somehow control/blow it out?.
    No, it doesn't "snuff out" the fire, but it does help push the heat and smoke away for easier entry, but you have to know where the fire is and be ready to attack it, otherwise it will spread. Ventilation is a must!

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    Wow, I thought this was common knowledge in this day and age. Most of what I am reading here is not the proper use of PPV.

    PPV is designed to be used BEFORE your initial entry into the structure. The principle is that by pressurizing the room/building higher than the exterior, the products of combustion will be forced out faster than they can be produced. This results in the fire being almost "Blown" out, and simultaneously cooled below the flashpoint. Once the PPV has begun to work, you now make you interior attack, supposedly with greatly improved visibility.

    There are a few points to remember about how to effectively use PPV.

    1. The fan must be outside the door and 5-8 feet back for a man door, 8-10 feet back for a garage door. The air "cone" should essentially cover the door, and not recirculate smoke back into the building.

    2. The exit point must be smaller than the entry point. i.e. if you are blowing in the front door, you must only break a small-medium window as the exit point. If you are blowing into a garage door, you can blow out a man door. As mentioned earlier, if too much glass is gone, the PPV won't work nearly as well.

    3. There should be an open path from the entry point to the exit point. This is not an absolute, but it greatly improves performance, and limits undesired extension.

    4. The fire will flare upon initially placing the fan, but after 10-30 seconds (depending on the size of the room/building), it will kick in quite dramatically. Under the most ideal conditions, I have walked down a hall with the smoke being pushed away almost as fast as I could walk.

    5. You can use PPV on larger fires if the fire has not self ventilated yet. It works best if you can "compartmentalize" the fire, or fight it one room at a time while keeping the others closed off. this can get a little complex and takes practise.

    6. You can install water jets on your PPV that will allow it to cool the interior very rapidly as it works. The one downside to PPV that we find up here in the north is that if used as a simple smoke ejector on small fires it can cool and freeze the interior of the building very quickly (pipes and all)

    There are some excellent videos out there that show PPV being used very effectively. If you aren't following the rules, it could be useless, or dangerous. But when it works as designed, it is very impressive to see.
    Last edited by mcaldwell; 02-05-2004 at 06:51 AM.
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    Uh,not exactly.You need to be in entry mode BEFORE cranking up the fan.PPV is used in CLOSE co-ordination with attack and vent crews.When used properly with co-ordinated fire attack,the process helps improve visibility and remove heat allowing a deeper and faster attack on the seat of the fire,NEVER BUT NEVER energize the fan until your attack crews are in position and ready to go,if you do you'll burn the building flat.As others have stated, if you have well trained, experienced crews it works very well.If not,perhaps you should practice on a acquired structure.It's not for everyone.I've used the principles several times on our trainings but we're not ready yet to use it on every job. T.C.

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    I STILL see a lot of fire departments screwing up. Even after proper training, the PPV fan is being set inside the doorway, and not several feet back from it.
    Ever seen one sitting inside the doorway facing OUTWARD? I have. I guess they thought it was a super-duper smoke ejector.

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    Yes I have seen fans inside the doorway blowing out, usually that is negative pressure ventilation and most times there is another fan inside the stucture pushing the smoke outside of the sturcture.

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    Exclamation PPV warnings

    I would not use PPV in a fire attack.

    Do we know the construction of the building?

    Do we know if the firestops have been compromised, creating void spaces and pipe chases that will push the fire to other location in the building?

    Is everyone out of the building?

    Ten years ago, a former Chief of a neighboring Department tried using a PPV in conjuction with aninterior attack. The problem was... the building was a balloon frame Victorian..and yes, they lost it.
    ‎"The education of a firefighter and the continued education of a firefighter is what makes "real" firefighters. Continuous skill development is the core of progressive firefighting. We learn by doing and doing it again and again, both on the training ground and the fireground."
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    Default Re: PPV warnings

    Originally posted by CaptainGonzo
    I would not use PPV in a fire attack.

    Do we know the construction of the building?

    Do we know if the firestops have been compromised, creating void spaces and pipe chases that will push the fire to other location in the building?


    Thanks for all the responses guys, really answered my question!. But after reading all of the responses I think I will stick with CaptainGonzo on this one. I'll take crawling down a hot smokey hallway or entry way over possibly burning the whole place down or even worse burning a trapped victim that is somewhere in the home.

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    Default Re: Re: PPV warnings

    Originally posted by firefiftyfive


    Thanks for all the responses guys, really answered my question!. But after reading all of the responses I think I will stick with CaptainGonzo on this one. I'll take crawling down a hot smokey hallway or entry way over possibly burning the whole place down or even worse burning a trapped victim that is somewhere in the home.
    On the other hand pushing the smoke and heat out of a structure may just save that trapped victim.
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    Alot of different perspectives, but im going to have to go with Rescue 101. We have used this several times, but most all on single family dwellings and it works excellent. We don't have any or many ballon construction homes in this area, but I could see where that might be a problem. It sure does increase the fires intensity, but on the positive side of that you can usually see the fire when you approach it, and if there are victims inside the ppv is introducing fresh air and pushing out the smoke, also facilitating in seeing a victim. Ive seen many times guys going in and spraying water at smoke cause you couldn't see the fire, increasing the water damage and any other things we break cause we cant see, these PPV's help mitigate these problems. They cant be used on everything but than either can a 13/4, they are good tool with proper training and recognizing the situation at hand. With all respect to Captain Gonzo To say 'I would not use a PPV on a fire attack' is kinda old school isn't sir (you crusty jake),we have to learn how to crawl before we learn how to search.
    Just my opinion.
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    Red Flag Quotes

    ...once you get water on the fire and achieve knockdown then you can start the fan to clear the smoke and whlie finishing extingusihment see if it makes any other hot spots light up...


    ...We try to get the PPV going as soon as possible after the initial knockdown...


    If you're going to use PPV, and I wouldn't, PLEASE, shut it down ASAP after knockdown. The opening of walls and ceilings to check for extension while PPV is operating can have severe ramifications!

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    Default food for thought (yummy!)

    With all respect to Captain Gonzo To say 'I would not use a PPV on a fire attack' is kinda old school isn't sir (you crusty jake)
    "Old school and experience (aka "crust") beats "new school and book knowledge"!

    An example for my reasoning...

    There is a new home under construction just down the road from me. It's going to be a 4 bedroom, 2.5 bath Colonial with a two car garage under.

    The floor joists are made of plywood I beams.
    The walls are standard 2x4, 16 inches on center.
    The sheathing is OSB.
    The subfloors are plywood.
    The roof is being supported by lightweght wood trusses.

    While it is Class 5 platform construction... how many openings in the flooring and plywood I beams will be created running the wiring and plumbing? How many of these wil be properly sealed afterwards?

    Two red flags here are the plywood I beams and the lightweight roof trusses. Plywood I beams will delaminate quickly under fire conditions and a truss is a truss is a truss. Do you really want to use PPV in a fire attack knowing that information?

    While throwing a book at a vire will not help to put it out, it's knowledge from books penned by people with crust (Norman, Dunn, Smith, Brannigan, IFSTA, etc.) that help you make the right decision!
    Last edited by CaptainGonzo; 02-05-2004 at 03:48 PM.
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    Default Re: food for thought (yummy!)

    Originally posted by CaptainGonzo


    The floor joists are made of plywood I beams.
    The walls are standard 2x4, 16 inches on center.
    The sheathing is OSB.
    The subfloors are plywood.
    The roof is being supported by lightweght wood trusses.

    PPV or not, I'm not sure how long I'd want to commit to interior ops in such a building. We've got 'em here, too.

    I personally would not rule out a well-coordinated attack using PPV. They key is to know the buildings in your jurisdiction and err on the side of caution where lightweight or baloon construction is likely.
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    I was part of a crew that used PPV attack at a training burn in an aquired structure. It worked very well and we were chasing the smoke down the hallway right to the seat of the fire.

    Since this was a training burn, we knew exactly which room the fire was in which made our attack alot quicker, and the window for the vent "exhaust" was also in the same room which prevented the fire from extending to other areas.

    It was good to see how something we had read about worked but I'm not sure if I would want to try the technique on a real fire with the many variables that aren't present at a training burn.
    FTM-PTB-DTRT

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    The problem with PPV does not seem to lie within the attack. It is afterwards where the problem seems to be. Once you have the fire knocked down is where your problems can start. Once you start overhaul and begin really getting those walls and ceilings open you are very likely to push that fire all over the place. And no matter what type of construction the building is there are going to be voids for fire to run through. So it seems like the "old school" is the best way to go.

    And by the way can we really consider going in without PPV "old school" considering going in without PPV seems to be the most common (and effective)way of attacking a fire????

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    I think a few people are making mountains out of a molehills regarding some of the apparent cons of PPV.

    First of all, when applied correctly, PPV clears the gases and smoke out so quickly that it does not have time to gain a foothold in other areas. A small amount of fire pushed into a void for less than 5 or ten seconds will not usually continue to free-burn. It does not have enough time to superheat the area, and thus create the "Self-Sustaining" part of the reaction. If you have had a chance to practice with it to the point of proficiency, you would see how fast it really can work.

    Also, the excessive time required to do a slow crawling search can often allow more damage to these types of vulnerable construction than the time required to get up there and overhaul after your PPV has cleared it out. Remember, part of the theory of PPV is rapidly cooling the gases and structure to below the flashpoint. I can attest from experience, it works very fast.

    The benefit to the victims is clear. You are providing them fresh air very quickly, and spotting them much quicker as well.

    With respect to Gonzo, I don't think it is a book vs practice question. You cannot read a book and then go and perform effective PPV. Like traditional means of interior attack, it takes many practice fires to become proficient with the technique, and many dept's lose structures because the don't have that level of comfort and proficiency with the system. However, if you are willing to step out of your comfort zone and practice with it, once you get it down, it does save buildings, manhours, and lives.
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    For more info on PPV see www.firetactics.com. This is a British site that goes over several years of research into PPV. It explains in what circumstances PPV is effective and when it isn't.
    Additionally the US Navy has used PPV for years for shipboard fires (different that structural FF) within the skin of the ship. Naval Ship's Technical Manual 555 (Shipboard Firefighting) has different techniques for a shipboard environment.
    PPV is an effective tactic when used properly and in the right circumstances. It can also be harmful when improperly used. It is another tool we have to be used when needed.

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    I agree with Mcaldwell, PPV is very useful during attack. We have almost all balloon construction and we use PPV on nearly every fire. We coordinate the ventilation crews and attack crews because things happen quick, especially in a balloon. It makes conditions more tolerable and makes it easier to identify where the seat is so you can get to doing what you need to do. JMO

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    Default PSSSSsssssssssssssssssst...

    more info over here...........how did I let this sneak by ?
    http://cms.firehouse.com/forums2/sho...7&goto=newpost
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