PPV on Fire Attack

[wraftery 1,275]

I always had a Reason for doing what I did:

Line to interior..obviously treated sa a structure fire

AFFF...because dry chem will reignite if the surface is hot

Chains...to gently as possible knock down the creosote chunks..does no more damage than the chimney sweeps brushes

No PPV on attack...even the PPV gurus tell us that we need control of the openings (both interior and exterior) before using PPV. I have never had that control. For an example, look at something like a hi hat light. The fixture is loaded with vent holes. PPV will make good use of those holes to move fire where you don't want it. You would never open a wide angle fog line in the front doorway because it pushes fire. Why then would you start up a fan which does the same thing? Locate, CONFINE, extinguish...these three words are right up there with CRAWL.

PS:For overhaul, PPV is the greatest thing since sliced bread. Why now? You now can control the openings. Before you Attack PPV guys start throwing rocks at me, give me a little warning so I can get my helmet on.

I am not too old to change. But I've been to courses and demos by guys like Mittendorf and the West Coasters. The thing that always glares out to me is the CONTROL thing. The examples they use and the demos they build always have control because they built them to prove their point! Possibly NIST will be able to explain to me the scientific difference between Attack PPV and a Boy Scout blowing on a handful of tinder.

I personally favor the Coordinated Outside Vent/Interior Attack. Notice I said coordinated. It takes communications practice and finesse, but it works. I learned it in the early '70's from the Bronx guys when the "Bronx was Burning." The Bronx is still standing. The west Coast loses entire cities, as in "Well, we lost Oakland the other day." Then they build it back up with wood roofs again.

Sorry I left the thread on chimneys.

For the guys that asked. Here's the basic thread carried over from "Chimney Fires." Looks like you have my opinion on PPV during attack.

[wraftery 1,275]

antiquefirelt has a good quote on PPV in the Chimney fire thread.but I couldn't bring it over to this thread.

It's a good point, and should be read also.

[x129K 1,393]

I think the PPV technique for chimney fires is pretty dang neat.

PPV has been used in our area with good results, but luckily always later into the fire.

This video from www.vententersearch.com is an EYE OPENER and drives home the need for correct timing, as with any ventilation.

http://www.vententersearch.com/index.php?s=ppv

and let me add if it's OK; is PPV considered an effective alternate to vertical or horizontal ventilation?

Edited January 5, 2010 by x129K

[antiquefirelt 994]

I've been of the opinion that PPV/PPA can be an effective tool when all the factors align like the stars and moon. Typically the proponents are from warmer climates where tighter homes/buildings are typical, construction is newer overall and controlling ventilation openings is fairly easy.

For example, most homes in Florida have HVAC and rarely leave windows open, so controlling the vent openings is easier. Here in the Northeast, heat/cooling is very often regulated by opening and closing doors and windows, making it much more difficult to control the exhaust openings.

We also suffer the sins of the past and deal with a lot of wood balloon frame construction, which has always been a contraindication to PPA in my book. Somehow pressurizing the space and potentially pushing fire/heat/smoke into voids doesn't seem like a good idea.

Now, as I mentioned in the Chimney Fire thread, the guys from Slat Lake City have been big PPV/PPA proponents for awhile. Their latest article in Fire Engineering has me thinking maybe our experience was marred by poor training and understanding of the concepts and realities. They worked with NIST to study PPA/PPV in all types of situation and are confident that there shouldn't be a "push" of anything. Rather than blowing the fire like a bellows toward the vent, they propose we just pressurize the door we're entering and open the exhaust to create a low pressure for the higher pressurized air (smoke/heat) to flow towards. They note that the data shows that the fire and heat creates far more pressure than the fans.

I know that those that use it successfully think that it's nearly a silver bullet. While I'm still skeptical, I'm looking to go to the FDIC and take their class and then try it out with a better understanding than the way my FD used in the 90's. Who knows, maybe we'll find it still isn't for us, but some of the latest info is very interesting.

Edited January 5, 2010 by antiquefirelt