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PPV Tactics
Hey folks. Been a while since I've been here but visit the site quite often. Does your dept. utilize PPV? If so, how often. What conditions in your mind must be met before PPV is used? I've seen some disasters if used incorrectly. But seen some very good results. Seems some departments are still on the fence with the tactic. Your thoughts and insight are appreciated!
Replies to This Discussion
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Permalink Reply by captnjak on
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James Billings said:Iv'e read most of the comments and agree with most of them, but here is one big thing that was mentioned TRAINING!
At my department as a young lad we was tought how to use the PPV (Blow) and the smoke ejectors uses( They Suck) not in a bad way either, and proper placement of both and uses.
that being said the PPV is the second thing that is pulled off the engine and is placed 10 feet or so from the door and is running at idle till the entry team is ready and gives the command to turn it in to the door way as they go in, this gives them some visual and cooling effect, and can improve victims chances by removeing super heated gases from the area.
the opening for the exhaust side of it is sometimes the window in the fire room its self or the closest rear door of a single family dwellings.
hold on before everyone gets bent out of shape, the use of ppv's is determined on that departments SOP'S, SOG'S and TRAINING!!!!!!!!!!!
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You say you turn the fan to the door as the entry team goes in. Proponents of PPA almost unanimously agree that there should be a waiting period of at least 30 seconds prior to entry. Personally, I believe it needs to be longer. This is meant to gauge the effectiveness of the fan. Maybe you have not been trained properly.
Using valuable fire ground time to gauge the effectiveness of a tactic is, IMO, counter productive. If it doesn't work, you've exposed victims to more heat and more toxic gases. Not to mention that if it doesn't work effectively, those heated gases will light up and fire will flash throughout the area.
I prefer tactics we know will work. Cooling the area with water ASAP. Aggressive search for victims and removal from the fire environment instead of trying to remove the environment from them. These tactics are tried and true. They never fail. There is no waiting period.
You mention the visual improvement for the team as they enter. This is a nice luxury but in no way necessary to do the job. Our tactics should not be designed around what is desirable for firefighters. Safety yes. Comfort no.
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Permalink Reply by Mike Pasqualicchio on
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You mention training, which is paramount to accomplish PPA. I have yet to see real world training that mimics a fire ground. Having a pallet and hay near a window in a cinder block tower does not give an idealistic setting to practice PPA. I watched and read the LV training mishap with the PPA experts and was disappointed with the arrogance that went towards it, not by the members but by the experts. When performing PPA, do we know if the door is shut, holes in walls or ceiling, are we contributing to fire spread. Door control to the fire room would alleviate a majority of the problem. The lag time between finding an adequate exhaust followed by clear, concise radio comms (barring no hiccups) or equipment malfunctions adds to the many variables that have to completed to the exact. There is no room for error. A fire ground is not designed to be clear cut like that. What type of residence is this being performed on.. single story, 2 story, Victorian. Is it done with fire showing from a single room, multiple rooms etc. PPA has its place buts it involves a very small amount of fires.
James Billings said:Iv'e read most of the comments and agree with most of them, but here is one big thing that was mentioned TRAINING!
At my department as a young lad we was tought how to use the PPV (Blow) and the smoke ejectors uses( They Suck) not in a bad way either, and proper placement of both and uses.
that being said the PPV is the second thing that is pulled off the engine and is placed 10 feet or so from the door and is running at idle till the entry team is ready and gives the command to turn it in to the door way as they go in, this gives them some visual and cooling effect, and can improve victims chances by removeing super heated gases from the area.
the opening for the exhaust side of it is sometimes the window in the fire room its self or the closest rear door of a single family dwellings.
hold on before everyone gets bent out of shape, the use of ppv's is determined on that departments SOP'S, SOG'S and TRAINING!!!!!!!!!!!
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Stephen Duffy said:hi there, we use PPA and PPV routinely. im always amazed to hear pro firefighters and officers dismissing forced ventilation.
the criteria we have here are, to use PPV in any phase, you must have 4 things on place
inlet
outlet
clear route
excellent comms
PPV is an awesome tool to have at your disposal.
hope this helped :)
Is it really that simple though? Inlet, outlet, clear route and comms? How big is the inlet? How big is the outlet? How do you know how big they need to be w/o actually trying it (and possibly wasting valuable time)? How do you know the route is clear? Are you sending someone in to actual fire area to find out? If so, you've done so w/o any of the benefits of PPA. So why not have a team go in with a line and just put the fire out?
I've posted several very detailed replies in this thread that have listed my concerns about PPA and firefighter safety. My concerns are based on modern fire behavior and building construction methods. Several others have agreed with my take. You've replied in a very dismissive fashion with about 50 words.
In the interest of helping out the brotherhood, can you do better? Can you address the specific concerns of myself and others?
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Permalink Reply by Don Catenacci on
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Stephen Duffy,
You just danced around captnjak's entire point about vagueness. This statement proves that there is no definitive answer on the proper size of the exhaust opening " If you have ram fans then the outlet needs to be large enough to ensure you don't cause a back pressure which will result is some very unpredictable fire behavior, and may send flaming combustion and its products back towards the inlet." How large is "Large enough?" What happens if it is too large? You already described the catastrophic events that can occur if it is too small.
In your definition of phase 2 let me be clear in what you are saying. You claim a need for a clear path to the fire area before initiating PPV/PPA yet when you suspect the path may not be clear you are putting firefighters in the flow path of the fan as they enter to check to see if the path is clear? How exactly does that provide for clearing conditions if the path is NOT clear? How does that not, in fact, endanger them?
Not trying to be hyper critical but I would not want to operate in a building with PPV/PPA under the guidelines you have posted here for fire attack.
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If you've got a team with a hoseline "on top of the fire", why not just vent horizontally ahead of that hoseline and extinguish the fire? One main stated advantage of PPA is that it makes the hoseline advance easier, cooler, more visible, safer, etc. But you've already put a team in there with NONE of these advantages. So why start messing around with fans now? What if the opening is not big enough to exhaust the amount of heat energy present? Even with a hoseline in place, things could get real ugly real quickly. What if the hoseline is not sufficient to cool the heat energy present if the entire area lights up because the exhaust opening was insufficient?
Almost everyone else who supports PPA says the fan should be operating for a while BEFORE the team enters. You appear to be in the minority on entering before fan is started.
I assume a sealing fan will seal off the entire entry point opening? Again, the majority of supporters call for an opening at the top of your entry point that will allow for back pressure to vent. This is the point used to monitor fan's effectiveness. This trial and error aspect is one of my main objections to PPA.
Lastly, I have read and seen in most instances that the exhaust point should be 2-3 times the size of the entry point opening. More conflict amongst the PPA believers as I've also seen your number. The variety of numbers is another main objection I have to PPA.
I don't dislike PPA just for the sake of disliking it. My department doesn't use it. I'd love to be proven wrong because I think there is a real safety issue here. I think it warrants intensity.
Don can correct me if I'm wrong but I believe in the past he has used PPA when it was felt to be appropriate. I believe he and his department have changed their course on this.
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I am of the opinion that a blockage or insufficient exhaust opening with PPA in place could cause the entire area to light up and the fire to expand rapidly. This would, of course, be counter productive. Certainly not good for firefighters or occupants. All the training in the world does not change the trial and error aspect of PPA. And if you try it and it doesn't work, valuable time has been wasted. Again, not good for firefighters or occupants.
Some of the "localisms" in the fire service (whether America, UK or elsewhere) are what scare me the most, as the physics of fire behavior is very consistent.
PS. I appreciate the debate, regardless of our differing opinions.
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captnjak,
You are correct that it was an option for fire attack. We had the option to start the fan, make the exhaust opening, let it blow to clear heat and smoke, and then advance to hit the fire. I have never seen us do it at a "Real World Incident" though. My belief is we will follow the NIST/UL/FDNY findings and work to control the flow path by closing the entry door most of the way after entry to limit oxygen to the fire. Let natural venting, the window breaking, be the vent, or pop the window coordinated with attack.
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Permalink Reply by Zachary Wolf on
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In my limited experiance (9 years) I have only seen a ppv used a handful of times its only been after fire attack has been completed or to remove smoke from a building after confirmed no visible fire.. although i disagree with the latter due to the fact that adding ppv to a hidden fire it leads to the fire growing and causing more issues. It has never been used when i was present for fire attack. I have never liked the idea of forcing air into a fire and never will. but that is just my opinion, and I will never use it on any fire that I am in command of
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Permalink Reply by Derek J Sinesi on
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I have been to training on PPV/PPA. I have been to 2 different classes on this subject. Both classes i felt that the instructors were just trying to sell a bill of goods. As we all know some pallets burning in a burn building is in no way the same as a burning building. What did stick out more then anything was the fact that the fire grow. The PPV did push the smoke and heat away but the fire got bigger. My question to both instructors was "If there is a person down on the back side of the fire, How the hell are they going to survive that amount of heat we just forced over them?" They answered what did i mean? So i explained it to them like this. If you put a turkey in your oven at home it takes 4 to 6 hours to cook. Now if you put that same bird in a convection oven (oven with a fan in it) that bird only takes 2 to 3 hours to cook. So by placing a fan at the door and a victim is on the back side of the fire we have basically forced more heat and gases to him. Plus we have initially made the fire bigger and hotter. Needless to say i didn't get a answer back from either of them. I also went back to the department and we decided we wouldn't be using PPV for fire attack. This is just from my couple of experience's with it. I think that by going in a putting the fire out is much faster and safer for all involved.
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Derek J Sinesi said:I have been to training on PPV/PPA. I have been to 2 different classes on this subject. Both classes i felt that the instructors were just trying to sell a bill of goods. As we all know some pallets burning in a burn building is in no way the same as a burning building. What did stick out more then anything was the fact that the fire grow. The PPV did push the smoke and heat away but the fire got bigger. My question to both instructors was "If there is a person down on the back side of the fire, How the hell are they going to survive that amount of heat we just forced over them?" They answered what did i mean? So i explained it to them like this. If you put a turkey in your oven at home it takes 4 to 6 hours to cook. Now if you put that same bird in a convection oven (oven with a fan in it) that bird only takes 2 to 3 hours to cook. So by placing a fan at the door and a victim is on the back side of the fire we have basically forced more heat and gases to him. Plus we have initially made the fire bigger and hotter. Needless to say i didn't get a answer back from either of them. I also went back to the department and we decided we wouldn't be using PPV for fire attack. This is just from my couple of experience's with it. I think that by going in a putting the fire out is much faster and safer for all involved.
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I understand the issue you've raised. Proponents of PPA, from what I've seen, will tell you PPA is not an appropriate tactic when there may be a victim between the fire and the exhaust opening. How they're supposed to know the location of victims prior to an interior search is beyond me. No department I know of pretends to know the status of all potential victims without first having done both primary and secondary searches of the entire dwelling.
I have posed the question repeatedly and never once received a satisfactory answer.
The proponents of PPA, the guys who write about it and teach it, have an extensive list of conditions that make PPA an inappropriate firefighting tactic. By the time you get through the list you realize it is almost never appropriate to even attempt it. As I've pointed out before, they don't even really agree on how to do it. And when you do attempt it you are still left waiting to see how it works out, due to the trial and error aspect.
There are people who have built careers, reputations and businesses out of PPA Training. I suspect they will not let go of it easily. That doesn't mean we should buy into it on the fireground.
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Captnjak, I agree there was way more times explained when not to use it then when to use it.
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Stephen, You are correct in it just being a tool to be used or not is up to each department. I can not speak for others and their departments. But personally if i need to send guys in to make sure we have a clear path and search for victims then we are better off just putting the wet stuff on the hot stuff and being done with it. Water seems to solve a lot of problems pretty darn fast.
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