Positive Pressure Ventilation

Replies to This Discussion

Permalink Reply by Scott Kleinschmidt on December 6, 2008 at 11:38am

yes,
I guess I didn't do a very good job of explaining. PPV and PPA are two totaly differant animals. PPV is used to augment the vent process after the fire is out. We cut a h*** or take windows let it vent, hit the fire and then use the fan to help remove remaining smoke.PPA I am making exit opening opposite side of fire pIacing a fan at entry and letting it "push" the bad stuff in that direction. PPA is a very dangerous tactic in the wrong untrained hands.

Brian Arnold said:

Scott,
Can't beat you up too bad over anything you stated. You guys are aware that there are major differences between PPV and PPA even though the fan gets used in both. There is a time and place for each, but the FAN doesn't take the place of normal truck company operations and sound ventilation tactics.

Brian

Permalink Reply by Jeff Schwering on December 6, 2008 at 3:33pm

Scott, in my area PPV AND PPA are to some the same animal. That't where traing has to come in or someone is going to get hurt. Like I said in my post, our fan comes off the engine, is started facing away from the door and is called for by the interior or attack officer. PPV/PPA has evolved a long way in my area of the county, since that first chie knocked a small in a window and burned his guys in a training fire.

Stay Safe

Permalink Reply by Scott Kleinschmidt on December 6, 2008 at 6:00pm

Jeff,

If you trace back the the early stadges ( Europe) of using a fan to push out heat and smoke ahead of the FA team they refered to this as PPA.

PPV ( is post suppresion) PPA is (pre- suppresion) per defination. Two totally differant Tactics (similar in a fan is used) but tacticly differant.

Even most articles and training done state side over the last few years utilizing a fan prior to entry was and is called PPA. They do this so guys (who as in my Department and a lot of other Departments) that have been using a fan for 20 years post fire understand that tactics are differant when you introduce a fan prior to entry.


When fans first hit the fire service they were sold as a way of replacing the smoke ejectors in removing smoke. You could take a fan pressurize the structure and push it out faster than sucking it with a ejector. ( post fire)

Now that some in the fire service are teaching in certain situations using a fan prior to attack. They call it what is (Positive Pressure Attack).

PPV and PPA are two differant animals by nature of time line and application in the fire service.

This is why early on they told you to get a good "seal" on the structure with the fan to maximize the pressue to push the smoke out. (Post fire)

Now we have all scene the you tube videos and heard the story's of guys using the PPV tactics ( good seal) and tried PPA and bad things happened. PPA requires you pay close attention to air going in the entry and having a "large" exit at least 2 times the entry. Then you wait the 45 to 90 seconds to make sure the bad stuff isn't coming back at you. Then make entry.

I have not attended a formal PPA class but several guys on my Job have and say that PPA is a completely differant animal than the PPV we have done for the last 20 years.

Have you guys always used the fan prior to entry?

If so how long have you been using this tactic?

Have you ever had a bad outcome using the fan prior to entry?


Scott

Jeff Schwering said:

Scott, in my area PPV AND PPA are to some the same animal. That't where traing has to come in or someone is going to get hurt. Like I said in my post, our fan comes off the engine, is started facing away from the door and is called for by the interior or attack officer. PPV/PPA has evolved a long way in my area of the county, since that first chie knocked a small in a window and burned his guys in a training fire.

Stay Safe

Permalink Reply by Mike Walker on December 6, 2008 at 6:23pm

To Scotty K's comments:

I totally see the differences in terminology being PPV and PPA. When we started using the blowers it was all called PPV. It was a chief out of L.A that taught us how to use blowers for what is now called PPA.

Permalink Reply by Mike Walker on December 6, 2008 at 7:27pm

To clarify PPV during High-Rises: The blower goes at the base of the stairwell, not on the fire floor. Also, it's initial purpose is to assist with evacuation and not necessarily fire attack since F/A may be stalled until evacuees get below the fire floor or until evacuees are redirected to the designated evacuation stairwell. Having a blower at the base of the evacuation stairwell is a very good idea and should be seriously considered. Recently, our department purchased several electric blowers for this purpose.

Permalink Reply by Jeff Schwering on December 6, 2008 at 8:59pm

Scott, Thank you for filling me in on the background of where PPA came from, I learn something new everyday. I just had the opportunity to show one of our newest guys on the dept the post. Outside of giving me trouble because I can't spell, he said he had heard the term PPA used on his volunteer dept, but never in our county. The terms seem to be used interchangably here in St. Louis County, even though some know the difference.

Thanks Brother!
Jeff

Permalink Reply by Jeff Schwering on December 6, 2008 at 9:09pm

Scott, to answer you questions, we don't use the fan prior to attack, it is set up outside, the attack officer calls for the fan when the fire is knocked down. The fan, obviously is not our only vent tactic either. We have been using the fan for 14 of my 18 years at this dept. Never had positive pressure at the dept I used to work for. Sorry for the back to back replies. My computer at work leaves much to be desired.

Stay Safe

Permalink Reply by Jim Mason on December 6, 2008 at 9:28pm

Ok So I read your replies on this and I'll admit I haven't read the NIST reports fully but I think I have a good understanding of them. They invited me down when they were in in Chgo but I couldn't make it at the time. I took Dan M"s class from NIST last FDIC also. The parameter uses appear to be very small for this in the pre control time on the fire ground. With all that said, here's another question on this - With standard type venting, my mistakes can almost always be "fixed" if I move fast enough. If the fan is used incorrectly, I don;t have time to recover becase ithe change of conditions are so quick. And then the fan needs to monitored when in use , if I get jambed up because there is a lack of coordination to begin with when the fan is started then I have to radio for it to be shut down also while I'm in trouble. It seems difficult and dangerous in that sense because I don;t think that as a whole the fire service coordinates the attack too well to begin with ( but certainly not the members of this fine web page ). This is actually the class I'm presenting at FDIC "Coordinated Fire Operations" (to plug it, I guess, ha-ha). So I could see using it in the PPV mode to cler the building after the knock down has happened but I don't trust the coordination of the PPA thing. High rises stairways being pressurized by the fans not included in this comment. What would the parameters for use be for the PPA thing?

Permalink Reply by David O. Couvelha on December 6, 2008 at 11:28pm

Scott,

You've hit the nail squarely on the head. Unfortunately, there is still much confusion out there caused largely by the term PPV used for either PPV or PPA. And as you've correctly pointed out, they are apples and oranges, only connected by the use of the same fan.

My old department has been successfully using PPA for the last 17 or 18 years. Granted, our district is largely residential, one- and two-story frame structures. We are not faced with the three- and four-story walk-ups like many older cities, so I cannot speak for its use in those applications. Nor were we faced with multistory apartments. But in our situation, it works very well.

The fan goes to the entry and is fired up while the line is pulled and the entry crew gets ready. As you so correctly pointed out, the cone is adjusted so that the uppermost portion of the door is not covered. If the fire has not already vented itself, the vent is made. Only then will the crew make entry.

We did not have the use of a ladder truck, so vertical ventilation via ground ladders would have taken us longer than PPA did. Manpower considerations also come into play. With distant response times to the rural parts of our 78 square mile district, and the distances for our auto aid departments often meant that initial attack went in with under 10 personnel on-site.

I did have the occasion to watch German firefighters use PPA back in the eighties when I was stationed there.. Most of their structures are one or two stories, masonry construction, with clay or cement tile roofs. Lots of heat build-up. Their fire flow was considerably less than what we typically see here in the states. They used PPA very successfully.

My two cents. I'll step down off my soapbox now.

Stay safe.

Scott Kleinschmidt said:

Jeff,
If you trace back the the early stadges ( Europe) of using a fan to push out heat and smoke ahead of the FA team they refered to this as PPA.
PPV ( is post suppresion) PPA is (pre- suppresion) per defination. Two totally differant Tactics (similar in a fan is used) but tacticly differant.

Even most articles and training done state side over the last few years utilizing a fan prior to entry was and is called PPA. They do this so guys (who as in my Department and a lot of other Departments) that have been using a fan for 20 years post fire understand that tactics are differant when you introduce a fan prior to entry.


When fans first hit the fire service they were sold as a way of replacing the smoke ejectors in removing smoke. You could take a fan pressurize the structure and push it out faster than sucking it with a ejector. ( post fire)

Now that some in the fire service are teaching in certain situations using a fan prior to attack. They call it what is (Positive Pressure Attack).

PPV and PPA are two differant animals by nature of time line and application in the fire service.

This is why early on they told you to get a good "seal" on the structure with the fan to maximize the pressue to push the smoke out. (Post fire)

Now we have all scene the you tube videos and heard the story's of guys using the PPV tactics ( good seal) and tried PPA and bad things happened. PPA requires you pay close attention to air going in the entry and having a "large" exit at least 2 times the entry. Then you wait the 45 to 90 seconds to make sure the bad stuff isn't coming back at you. Then make entry.

I have not attended a formal PPA class but several guys on my Job have and say that PPA is a completely differant animal than the PPV we have done for the last 20 years.

Have you guys always used the fan prior to entry?

If so how long have you been using this tactic?

Have you ever had a bad outcome using the fan prior to entry?


Scott

Jeff Schwering said:

Scott, in my area PPV AND PPA are to some the same animal. That't where traing has to come in or someone is going to get hurt. Like I said in my post, our fan comes off the engine, is started facing away from the door and is called for by the interior or attack officer. PPV/PPA has evolved a long way in my area of the county, since that first chie knocked a small in a window and burned his guys in a training fire.

Stay Safe

Permalink Reply by Wayne Benner Jr on December 7, 2008 at 3:37pm

We never use PPA? However we do use the PPV alot, method of vertical vs horizontal depending on the scene. We recently bought a Electrical PPV fan, which I dont like very much, as it just means setup time is longer. Someone has decided it can be used inside the building now for ventilating as it doesnt create CO.
We have NPV fans which are also electrical. I believe these should be used before the E/PPV fan.

2 weeks ago we had a pot on the stove on the 3rd floor and I watched a firefighter bring our Gasoline PPV fan in. I stopped him and told him he couldnt use the gas fan inside. He stated he could that he was taught he could. He was thinking of the electrical fan that was told to them could be used. Needless to say We used the NPV fan instead.

Keep your stick on the ice (Stay safe)
Wayne

Permalink Reply by Scott Kleinschmidt on December 7, 2008 at 6:13pm

Jim,

With my limited PPA experance (very limited) I would have to agree, I am "counting" on to many things to be just right. If something goes south reaction time is very limited. Fans in the "wrong" hands scare me.

As for the question on parameters and theory go to http://www.positivepressureattack.com/ and there is alot of info on parameters and theory for PPA.

But we all need to remember Theory vs. Reality. Theory is what the fire “should” do and reality is what it does!



Jim Mason said:

Ok So I read your replies on this and I'll admit I haven't read the NIST reports fully but I think I have a good understanding of them. They invited me down when they were in in Chgo but I couldn't make it at the time. I took Dan M"s class from NIST last FDIC also. The parameter uses appear to be very small for this in the pre control time on the fire ground. With all that said, here's another question on this - With standard type venting, my mistakes can almost always be "fixed" if I move fast enough. If the fan is used incorrectly, I don;t have time to recover becase ithe change of conditions are so quick. And then the fan needs to monitored when in use , if I get jambed up because there is a lack of coordination to begin with when the fan is started then I have to radio for it to be shut down also while I'm in trouble. It seems difficult and dangerous in that sense because I don;t think that as a whole the fire service coordinates the attack too well to begin with ( but certainly not the members of this fine web page ). This is actually the class I'm presenting at FDIC "Coordinated Fire Operations" (to plug it, I guess, ha-ha). So I could see using it in the PPV mode to cler the building after the knock down has happened but I don't trust the coordination of the PPA thing. High rises stairways being pressurized by the fans not included in this comment. What would the parameters for use be for the PPA thing?

Permalink Reply by Michael Bricault (ret) on December 8, 2008 at 3:02pm

Art, I hope I'm reading you right. Sounds like your looking for more of how PPV information is taught/passed along and reinforced as apposed to the actual SOP or specific PPV criteria itself.

As much as the AFD reviews material, CE's and trains each year, the one topic we really don't hit annually or regularly with any degree of frequency is PPV.

PPV is addressed in depth during the recruit phase of training. The next time firefighters review this material is during the promotional process for company officer when the training bulletins and SOP's are studied. The newest SOP's do create a more rigid guideline as to the application of PPV and attempt to answer as many questions as possible, taking some of the guess work out of the decision making process, but as you know, every situation cannot be anticipated.

The only other time this subject comes up is if there has been a change to the policy or equipment used. Then it is usually covered during morning roll call and typically in a brief format covering the addition and/or change and not the entire policy or procedure. Definatly not the best system or method for addressing this topic but its what we do given the limitations of maintaining more essential, required training and necessary certifications for 800 firefighters. Interestingly enough, the department internally maintains all certifications including emt, and paramedic so that CE's are taken care of on the clock and not by individuals on their off time, thus limiting training time and access to the City Fire Academy.

Despite these perceived shortcomings, our on scene ventilation procedures are generally (usually) fairly well coordinated. I believe this can be attributed to a good base level of training as well as the fact that ALL operating personnel are radio equipped. Everyone knows the game plan and has as much information as the IC.

Also, our prevalent use of PPV affords us the opportunity to teach and mentor our newest firefighters in proper PPV use and application (do's and don'ts) in a real time, real world setting which is arguably a better, more common sense approach for making a classroom lesson stick.

Like many departments, after 700 hours of intensive basic training, we depend very heavily on the mentorship process for our new members to be taught, trained and inculcated in to the procedures, policies, tactics and tradition that was imparted during during the basic training phase.

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