PPV and Rapidly Changing Conditions
We have all seen multiple videos out there of PPV mixed in with some other factors causing some very dangerous conditions. We understand that some departments heavily use PPV, some do not use it at all, and many others will use it with certain conditions. We are not here to take on this never ending argument, but rather we take a close look at what can go wrong and how to prevent this if your department does use fans. Many of our mentors have explained how one of the most dangerous tools on the trucks can be the fans if used without the proper understanding and conditions. The most dangerous combination is by instructing a firefighter to blindly place a fan at the door every time without paying attention to construction, fire location, pre-fan conditions, and even more importantly to the conditions after it has been placed. If we use fans we must be very educated and well versed on what can go right and what can go wrong during the operation. Anyone that has comments regarding what you’re looking for, contradictions, personal experiences of when it may have worked good or bad, please share so all of us can learn. As always we will not post comments that are strictly made to bash departments that are in this video or are otherwise not constructive.
Here is a great video put together of a recent incident that occurred. Thanks PJ for tipping us off to this video from www.firefighterspot.com
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Explore posts in the same categories: 4. Ventilation
Tags: Close call, Fans, Fire Behavior, PPV, ventilation
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IRONSandLADDERS.com 
05/13/2010 at 2:17 pm
Not being a huge fan of the fan, I will limit my comments to the fact that I was taught the fan belongs behind the fire attack team. It seems like, in this case, it was set up to blow directly at them.
05/14/2010 at 8:46 am
There is a So.Ca. dept that is using the PPV/PPA on many of there fires, however they are doing it under certain strict conditions. While there may be a place and time for PPV it needs to be carefully monitered as conditions change. There are several videos on youtube of brother & sister firefighters using the fan and creating flashover conditions for the crews inside. If you are going to take on this tactic, make sure you know your building construction, fire and smoke behavior and able to recognize pre-flash over conditions…
05/14/2010 at 2:44 pm
[…] on this video and they deserve all the credit, I’m just spreading the gospel on this one. https://ironsandladders.com/2010/05/13/ppv-and-rapidly-changing-conditions/ Take a look at their site, and apply it to your company, and fire department. If this happened […]
05/14/2010 at 2:48 pm
Great stuff guys…..I linked your article to my blog as well averagejakeff.wordpress.com
I my self and not a fan of the fan during active phases of firefighting. Ive just seen it fail so many times.
05/15/2010 at 12:13 pm
Another good “get your brain goin'” article/video. While my current FD is not big on using PPV during attack, I have participated in trainings and worked on other FDs that used it. It seems to be something that works under specific circumstances and obviously can get crews in trouble when used at the wrong time/wrong way. Many understaffed FDs(mine included) seem like they forget sometimes that we need people moving the hoseline to the fire. Taking people away for this(even just one!) can slow the nozzle down and possibly ruin the chance of quick knock down. I would personally like to see a concentrated and collective effort of firefighters putting the first line in place.
05/15/2010 at 9:59 pm
There is a time and a place for different types of ventilation. If you are using a fan and you still have hot smokey conditions you have to make sure you have a adequate exit opening to force the hot unburned particles of combustion (smoke) and gasses out of. This can be acomplished either by taking out windows in close proximity to the fire room or cutting a hole in the roof. Of course this will depend where the fire. Always size up the scene and be able to be flexible to change how you normally do things. Dont just put the fan at the front door or hallway with out thinking of the effect it may have on the fire conditions. Thank you for the fire department in the video to share their story and help us learn.
05/15/2010 at 10:57 pm
Thanks again to Irons and Ladders for providing some great education.
Like any other tactic used on any fireground in the country, the PPV fan is a tool. And tools have been engineered and constructed throughout civilization, usually with a specific purpose in mind. The hammer when used correctly can drive a nail into a piece of lumber proficiently and effectively. When the hammer is not used right, or the user is not experienced, or the user gets lackadaisical the nail bends and is not driven into the wood or sometimes the user’s thumb is struck with a painful force causing the gain of important knowledge and experience (I remember throwing the STUPID hammer across the garage or yard a few times!)
Unfortunately for many firefighters in our history the gain of that knowledge and experience has come at a much greater price. It is imperative that we take the learning for which they paid so dearly.
I agree with some of the above comments that state that knowledge of building construction and fire and smoke behavior is essential when applying a PPV fan. Also agree that the PPV fan should not be used at ALL fires. However the PPV fan is a great tool and an extremely valuable tactic when used correctly. Anytime a PPV fan is used there MUST be an exit opening for the pressurized smoke and heat to exit the structure. This exit is usually in the room of origin or closest available exit. The CFMs produced by the PPV fan clears the smoke from the structure quickly allowing the nozzle team to reach the fire room quicker and easier for faster extinguishment. After the main body of fire is knocked down smoke clears rapidly allowing for clear visibility of the room. The firefight is NOT over at this point, as with all fire, overhaul must be started immediately, walls and ceilings must be opened to expose and extinguish any possible involved void spaces.
05/16/2010 at 2:17 pm
Ventilation should be evaluated as a top down process.
If vertical ventilation is required it must be accomplished
immediately. If vertical ventilation is not necesary or can not be
accomplished I tend to lean towards natural horizontal ventilation
before considering the fan. A well placed window vent can make fire
attack and search significantly easier for the hoseline to make it to
the seat of the fire. Not to mention the improvement in conditions
for any trapped occupants. PPV is greatly dependant on conditions but
it works best on small room and content fires. Anything involving
multiple rooms or involving the structure in any way should be
vertically ventilated if possible. For me this video brings to light
several interesting points. Because of editing it is difficult to say
with any certainty when the footage was occuring (before or after the
initial attack and PPV, etc.). The initial smoke conditions appeared to be
nominal. Light gray smoke under moderate pressure that seemed to be
lazily exiting from all around the house. I think this is a good
indication of a basement fire. Smoke hanging around and not obviously
exiting or under significant pressure from one certain area always
makes me think subgrade fire. Even the initial company said the fire
looked easily manageable when they arrived on scene. Secondly. I
think one of the most important factors to consider is that as soon as
the fire is knocked down the initial attack team and the truckies need
to open the walls and ceilings and ensure there is no hidden fire. Delay PPV until you are certain the fire is out.
Obviously with this fire there are a lot of variables that we are
unaware of. The most important lesson is not to use the fan if you are
unaware of the fires location or are unsure if it is extinguished
completely. Fire Engineering ran an article in November of 2009 on
PPV and its uses. Excellent read. Here’s the link:
http://www.fireengineering.com/index/articles/generic-article-tools-template/_printArticle/articles/fire-engineering/volume-162/issue-10/features/ppv-in_single-family.html
05/17/2010 at 9:09 pm
As we all know, there are few absolutes in this world, and so too in firefighting. However I believe there are two absolutes with using the PPV fan, it should NEVER be used without a ventilation opening to allow the power of the fan to force out hot gasses and smoke. Nor should the fan be used in balloon frame construction. The open and interconnected void spaces in this type of construction are avenues for rapid fire spread and a PPV fan will push fire through out these open void spaces.
This is not the case with platform construction, the void spaces are compartmentalized. Or at least they were, now we have open parallel cord truss floor systems, and cold drawn metal C-channel studs with convenient ready made access for utilities. They are still compartmentalized to the level of origin.
I still believe, however, that a fan at the front, turned in with the attack team (ventilation opening in the room of origin) will clear the heat and smoke making the fire attack faster and safer. Of course, once the main body of fire is knocked down, sheetrock must be pulled to expose wall and ceiling voids, and extinguish any possible hidden fire. This tactic has been done at the majority of fires in my department since I have been in the fire service with (as far as I know) no detrimental effects.
A negative aspect of the PPV fan is the amount of CO introduced into the structure with the gas powered power head at the front door. The gas fan should be replaced with an electric fan soon after the smoke clears. The electric fan decreases the CO levels low enough to possibly finish the salvage and overhaul stage without SCBA.
As long as we continue to educate and train each other, we will increase our chances of going home in the morning. Thanks to all of you for the great learning!
05/19/2010 at 4:57 pm
First off, I am very glad to see that everyone made it out alive and they can share their story. Now on to business…
I would say that I agree with a lot, not all but a lot, of the above statements. I have watched this video several times before I decided to write anything and I also read all of the above comments. Without going into grave detail, PPV is dangerous when not used with all components in place. However, one of the things that I noticed is that nothing is mentioned about hoseline management. Of course I much more enjoy truck work but I am very confident in my hoseline management and nozzle control and Engine Co. operations. The only information that I ever heard of for actual fire attack was the initial knock down of the mattress fire. There was plenty of mention aout the initial knockdown and then the continued heat build up, but nothing more about actually spraying water. Did they ever knock out a window and open up the hose line? Understandably the conditions were not the best and PPV changes those conditions quickly. But one person performing ventilation, one using the Thermal Imager (TI) to monitor conditions and crew members, not TIC but thats another topic, and the other member operating the hose line to cool the atmosphere and attack fire. I believe that the best ventilation is proper vent point control, not over using the hose stream and over cooling the area but letting the heat rise and evacuate out the opening created by the Truck Co. or the other interior members. To cover my basis, controling your vent point does not mean randomly breaking glass because its something to do. Allowing natural ventilation and heat rise before placing the fan may allow you to use more of your senses before disturbing the fire environment with 16,000 (+/-)c.f.m. Sometimes just taking a little extra time before calling for that fan can lead you to find that there may be more to the bigger picture.