Positive Pressure Attack Challenge

Replies to This Discussion

Permalink Reply by Wayne Benner Jr on June 18, 2009 at 1:02pm

To look for negative outcomes just look up PPA on Youtube.
I recently took a PPA course and was ready to learn. Well I walked away knowing that I as an officer will keep the fan on the rig until the fire is out and we just need to clear some smoke. And or if it was a simple pot on the stive and we need to clear the house.
I will say that in Muilti Story buildings if used right we can charge the stairwells for victims to get out quick and aid the Firefighters. The only goodpoint I see in using PPV_PPA

This course I took they wouldnt use live fire???? We used artifical smoke? We didnt get to see the effects of the PPA. Then we were told the building had to be closed up and directed to the exit point to charge the building? So who closed all the doors to make this happen?

1. Appropriate size exit point established in acceptable location (in or near the fire room) What if its on the 3rd floor
2. No victim(s) in the exit point HOW DO WE KNOW WHERE THEY ARE?
3. Fan at hose team entry door
4. Hose team ready
5. Blower turned into door before firefighter entry SUPPOSED TO WAIT 30Secs
6. Backdraft conditions NOT present No but when we turn that fan all hell will break loose
If I find the videos I will post them here. And youll see the effects of using PPA.
My opinion its just lazy firefighter tactics that will kill us as there are to many questions that go unanswerd. Many books state this and that..My question is where do the books get their findings in controlled burns?

Permalink Reply by Jeff Goins on June 18, 2009 at 1:09pm

Excellent imput Brian. It all boils down to good well thought out Truck work. Too mays times I seen well meaning work not thought out.

Permalink Reply by Phil Jose on June 19, 2009 at 7:21pm

Wayne,

I can assure you there is very little possibility you will find a PPV video on youtube that I have not seen. Though if you post them I will look at them. Please take the time to review each example and determine if the situation fits the proscribed "done properly" that I put in my challenge. I understand completely what can happen when PPV is done either improperly from a functional side (too small an exit opening) or improperly from a procedural side (firefighters committed to the space) which is why I preface the discussion with the done properly.

Let me see if I can answer the points in you post.

1. A fire on the third flor would be a challenge for a PPA attack. There are several methods that would work and while they would be delayed I could make the case that the handline placement to the third floor would also be delayed. I'm not saying PPV/A would work every time. Nothing works every time. I could easily turn this question around though and ask what your ventilation plan would be for the same: Fire on the third floor of a 4 story building?

2. The idea of no victim in the exit point is - No victim IN the exit point. In other words they are not visible in an opening that could become an exit point for PPV/A. My feeling is that this is also a contra-indication to a direct attack for a fire in that area without first rescuing the victim. What would be your normal procedure for a victim IN a window that is likely to be part of the fire attack ventilation plan?

3. I am surprised that anyone teaching PPV/A said that all the doors had to be closed in the building to make PPV/A work. This is not the most up to date information on the tactic. The biggest problem with PPV/A relative to the exhaust is not having ENOUGH exhaust points rather than having too few. I have used the technique successfully plenty of times in SFD that had all the internal doors open.

I won't try to sell you on PPV/A. Just be aware that the tactic is used successfully by many departments across the country. If you look on youtube you will also see plenty of videos that show poor outcomes with horizontal ventilation and a few with vertical ventilation. I am advocating well-trained firefighters using the proper method at the proper time. There is a friend of mine in my department with whom I have this discussion regularly. Thanks for staying engaged.

Phil

Permalink Reply by Kristopher Holien on June 19, 2009 at 10:56pm

Chief,

I think you need to distinguish between PPA and PPV. From what I understand, they are not the same. In my world, PPV is used to expel heat and gases from a space AFTER a hoseline is in place and has begun the fire attack. PPA is done PRIOR to a hoseline being in place, and before the actual fire attack (water on the fire) has taken place.

This is a very important distinction. The terms are not interchangeable. it's like saying a 2 1/2 and 1 3/4 are the same because they both shoot water. In fact, they are both very different.

If you define PPA as using the fan PRIOR to the fire attack, and PPV as using the fan AFTER the fire attack, I think you might be able to get a less convoluted discussion.

That being said, I am still in favor of PPV, but for me, the jury is still out on PPA. There are too many factors and not enough evidence (granted I haven't taken the class) in real world emergencies. From our conversation the other day, I understand that NIST is looking into this method. It will be interesting to see what they find out. Again though, the lab and a controlled environment will not give you the same results as a real world emergency situation. Especially if you want firemen to stay at the front door, next to a fan and wait for an extra 20 to 30 seconds.

Phil Jose said:

Wayne,
I can assure you there is very little possibility you will find a PPV video on youtube that I have not seen. Though if you post them I will look at them. Please take the time to review each example and determine if the situation fits the proscribed "done properly" that I put in my challenge. I understand completely what can happen when PPV is done either improperly from a functional side (too small an exit opening) or improperly from a procedural side (firefighters committed to the space) which is why I preface the discussion with the done properly.
Let me see if I can answer the points in you post.

1. A fire on the third flor would be a challenge for a PPA attack. There are several methods that would work and while they would be delayed I could make the case that the handline placement to the third floor would also be delayed. I'm not saying PPV/A would work every time. Nothing works every time. I could easily turn this question around though and ask what your ventilation plan would be for the same: Fire on the third floor of a 4 story building?

2. The idea of no victim in the exit point is - No victim IN the exit point. In other words they are not visible in an opening that could become an exit point for PPV/A. My feeling is that this is also a contra-indication to a direct attack for a fire in that area without first rescuing the victim. What would be your normal procedure for a victim IN a window that is likely to be part of the fire attack ventilation plan?

3. I am surprised that anyone teaching PPV/A said that all the doors had to be closed in the building to make PPV/A work. This is not the most up to date information on the tactic. The biggest problem with PPV/A relative to the exhaust is not having ENOUGH exhaust points rather than having too few. I have used the technique successfully plenty of times in SFD that had all the internal doors open.

I won't try to sell you on PPV/A. Just be aware that the tactic is used successfully by many departments across the country. If you look on youtube you will also see plenty of videos that show poor outcomes with horizontal ventilation and a few with vertical ventilation. I am advocating well-trained firefighters using the proper method at the proper time. There is a friend of mine in my department with whom I have this discussion regularly. Thanks for staying engaged.

Phil

Permalink Reply by Phil Jose on June 21, 2009 at 12:13am

Hey Kris,

I agree with your distinction. The trouble is that NIST makes no such distinction, at least so far, when publishing about the issue. The additional trouble is that people cite examples and use the terms interchangeably. In the future I will stick with your examples of PPV versus PPA. They are the best!

One thing to take into account when you are considering options is that there are plenty of people who have a bunch of experience using PPA. I consider the laboratory evidence as a supplement to confirm what I have seen with my own eyes based on using the fans off and on since about 1990. It's great that the empirical evidence is finally being produced scientifically. That being said how much evidence would be enough to qualify for a transition from the "laboratory" to real life? (rhetorical)

Permalink Reply by Jimmy Grostick on June 22, 2009 at 1:18pm

Guys... Don't mean to hijack a thread, but kind of related....

I have been following this discussion, and the one re: PPA/PPV about a few months ago. Our station agrees about the proper application of the fan, depending on whether it is for during attack vs. smoke removal (food on the stove, post fire stuff)...

Our Department is in a consolidation with another neighboring district. We all use the I-Chiefs/IFSTA book as the basis of training. Beyond that however, is where things get 'sticky'..... The current TO teaches and preaches from the book. (I can't argue with that)....It is beyond the book is what we are struggling with.

Recently, we had a IFSAC FF1 test where a majority of the candidates were from the "other" side. We had one student there from our house.... At the ventilation station, the scenario was: "You are first due at a fire where you find a smoke charged house. There are victims inside. It is undetermined where the fire is. You are to set up the PPV to ventilate the house."

Of course, "our" candidate stated that he would not set up the fan in this situation. But for the "test situation" he would ensure that there was an adequate opening, and then start the fan, with cone, yada yada.... He was failed by the proctor in that he stated his opening to be the same size if not bigger. He went along with the "test" and followed what the folks wanted to get thru the testing process on the retake. Obviously he was a little confused.

The situation I need some help / advice with from you is this.... How have you implemented this type of teachings to a Department for training? When I look thru the book, I see it as a "how" and not the tell-all "why" application of. This includes everything from FE, hose streams, ladders, etc, etc..... Yes, I believe that we as a Department need to follow a standard operating procedure. I also believe that if there is evidence that we need to revisit what we are teaching based upon new information, that we should adapt our ways, if needed. This subject has significant impact on fireground operations, especially when thinking of safety.

Our Department hosts/teaches for the County Academy, the other Department has a ATA Degree program in Fire Science.... You would think that we would have the best of both worlds with that type of program(s). We even have one Lt. who stated that we start the fan first, before an opening is made during attack.... :-0

I have searched and read numerous articles from NIST, PP Attack, Etc, etc to try to bring hard data to support/demystify this theory. We have all seen many instances where an improperly placed PP Fan has caused injuries, if not fatalities, to both civilans and FF's alike... Like at a recent class I attended, where is the "science" behind what we do, and not because of fire theory of what we have always done...

Permalink Reply by Brian Arnold on June 22, 2009 at 5:13pm

Jimmy,
I think you pose some really good points and bring up some valid questions that have been posted on other threads. Let me see if I can give you a mix of some of my opinions as well as facts.

1. I'm always suspect of any TO that only refers to one text and calls it gospel or never looks at other publishers. His office should be filled with text, videos, studies and information from classes that he has attended from a variety of authors. I know you may find this hard to believe (tongue in cheek) but not everything in the IFSTA books is correct. But if that is the curriculum you were taught from, then that is what the IFSAC accrediting agency will test you on. As firefighters we are constantly "students of the game" (stolen from Chief Chikerotis) and it is part of our jobs to constantly seek further education which will keep us and the civilians we protect safe in our day to day operations. But those are just my opinions.

2. The hard data that you seek is coming but it is ever so slow. NIST has done a couple of cursory studies that have started to show the impact of PPV but have not put into effect an in depth study of PPA vs PPV. Nor have they had the chance to conduct an in depth study of a full scale Single Family dwelling fire, one or two story with normal occupancy fuel loading. When they do this it will require constants, (ie. same house configuration, same fuel loads, etc.) which are very expensive, and also employ a variety of accepted and normal firefighting tactics. Can you see where I'm going? It's going to take more than one house and one burn to get it done. What they have done is some very good introductory studies on PPV and high rise fires as well as some good computer generated studies in fluid dynamics. You should combine these studies, along with your fire behavior knowledge and experience to come up with safe tactics on each structure fire. One approach will not work every single time.

3. So while there are missing components to the equations, we constantly challenge and share experiences of firefighters across the country to what tactics have worked and when they haven't. We base our opinions on our working fires and the studies that NIST and others have done to this point. Thus the great debate continues on.........I would be hard pressed to trust someone that says "always" and "never" whenever they are talking about fire behavior or fire tactics.

Hope that helps a little. Keep digging for information, I find new stuff everyday.
Brian

Permalink Reply by Phil Jose on June 24, 2009 at 1:32pm

It's great th you are asking questions.

I wouldn't use a single source for training. There is a significant difference between running a FF1 practical exam and performing on the fireground. I'm glad your guy had the smarts to perform as directed. The test has it's place but single source training is for beginners, not pros.

OK now on to your PPA questions. If you have the PPA book then go to their website. There are LOTS of resources there that describe in-detail the multitude of studies that have been done on using PPA. Probably the best is the one done in, I think, San Antonio? Anyway a city in Texas. (no direspect to texas just can't remember right now.) The only downside to that study is that I haven't found it publicly available without paying a fee for it. If you know someone who has the FDIC disck from (I think) 2008 you should be able to get their presentation notes and information.

The application procedure that the PPA guys have on their website is simple and effective (IMHO) and I have used it many times with the caveat that I had the fan on the truck and we arrived with the engine. My standard practice was to have the guys riding backward take the fan to the door with them automatically. Either myself or my driver (usually me) would ensure adequate vent and then crank the fan. By then the engine is ready to go and we are off to the races. Then we would set up for vertical and get the primary search started.

Trainig is the key. Like I said, the procedure is simple. Getting people to approach it systematically and diligently seems, for some reason, to be complicated which is why the "properly implemented" comes into play.

Hope this helps.

Permalink Reply by Mike Walker on June 24, 2009 at 5:12pm

disrespecting a texan..... that's funny

Permalink Reply by Phil Jose on June 24, 2009 at 11:23pm

OK It was Austin. Here is a link



http://www.me.utexas.edu/~ezekoye/rsch.dir/FDIC2005Handouts.pdf

Permalink Reply by Kristopher Holien on June 26, 2009 at 12:19am

We just got done doing the Fire Geek thing, and watching the NIST video on wind driven fires. It brought up some great points in regards to what happens inside a structure, once the window is broken and there is a significant wind blowing from what would be the fire room window to what would be the fire attack entry. This brought up an issue that hasn’t been addressed, and that is the effect of the weather on the PPA tactic. While I can't recall ever being on what I would classify as a wind driven fire, I have certainly been on fires where the wind was calm, but nonetheless still present. During PPA, an exit h*** would be made prior to the fan being turned inside, with a delay (presumably). Let's just look at a 5 MPH wind through the fire room window. How would this affect the atmosphere inside? I realize that eventually the fan would overpower such a small amount of pressure, but there is a delay.

The other point that the NIST video brought up was the Heat Release Rate (HRR) and at what measurement the room is able to flash. It boils down to a chair and a table, or 1/2 of a King size mattress, or a sofa. So how does the initial creation of the exit point affect the fire behavior, when the HRR is already potentially at the Flashover level (I told you I was Geeking it up)?

Also, my initial reservation to this tactic still remains that in a bedroom fire if the door is closed, you are allowing the fire to potentially double in size needlessly. Since the door acts as a barrier for the flow of the air, the fan's effect on the fire room would be miniscule, but the time taken could put the fuels into that range where a flashover is likely.

I am reminded of the basics of engine work. The faster the fire goes out, the faster most of the other problems go out as well.

Permalink Reply by Mike Walker on June 26, 2009 at 6:58am

Hey Kris

In an attempt to speak to your questions I think it is important to remember, that PPV in a High-Rise situation is somewhat different then other applications. The window should not be intentionally taken out in a High-rise until wind direction is known but if the window fails and a wind driven fire condition results, then PPV can be used to help alleviate some of the effect.

As to your other question about the 5mph wind. I try to emphasize to my students that PPV is an augmentation to horizontal ventilation. I realize this my stand in the face of strong proponents of PPV but I strongly believe that my statement is accurate. Once the window is gone, either by the fire causing it to fail or by a firefighter, the smoke movement should be observed. If it reacts the way you want it to, then the process can be sped up by using the fan, if the conditions aren't what you're looking for, then more attention needs to be placed on what happens if/when the fan is utilized. The blower can easily overcome up to a moderate wind but to do so the fan placement has to be perfect or damn close to it. The path must be closely monitored in order to maximize the slight pressure increase from PP. The size of the exit opening(s) need to be watched as well. Every window interior firefighters open inside the structure causes a reduction in pressure, thus reducing the blowers effect.

This, to me, is where the rub exists. PPV requires personnel to actively maintain, evaluate, monitor, correct conditions throughout the operation. Most crews are accustomed to performing ventilation and then moving on to other tasks once they have achieved the desired result.

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