1. #1
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    Default Positive Pressure Ventilation during Fire attack

    Just wondering everyone's opinion on using PPV during Fire Attack. Just went through a course on PPV operation and we are looking at implementing use of it during fire attack.

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    We have been using positive pressure ventilation for several years now and we do use it in conjunction with structural fire attack. It can be used "after the fire" for smoke removal (like the old electric vent fans) but its real purpose is as part of a coordinated attack. A few important points to remember:

    Practice, practice, practice...make sure all members know how to operate the fan and can quickly and properly place it and start it.

    Placement is critical; too close or too far from the doorway will fail to create the proper seal on the opening and the fan will be ineffective. If you have a smoke machine, or better yet a burn building you can use, smoke it up and try different placements, different sizes and locations of vent openings, until you have a good feel for what it can and cannot do.

    ALWAYS have a handline charged and the attack team ready to enter before applying PPV. Recognize that the fire WILL flare up when PPV is applied, so the team has to be fairly aggresive about entering behind the retreating smoke and getting to the seat of the fire. Firing up the PPV before the team is ready would not be a good move. (you can crank it up and have it running while the team is getting ready to enter; just wait to open the door until they're ready)

    Don't let firefighters bunch up in the doorway where PPV is being applied; it will mess up your ventilation efforts.

    Exhaust opening should be the same size or slightly smaller than the entry opening. Too large or too many vent openings won't allow the pressure to build in the structure.

    After the fire is out, interior doors can be opened and shut as needed to clear smoke from different areas of the structure.

    Building construction is important...99% of our structural fires are single-family, 1 story dwellings, and PPV works really well on these structures. I think the reason you don't see your larger cities using PPV much is because of different types of construction..multiple occupancies, larger multi-story buildings, etc. would make PPV ineffective and demand different tactics. So what you have in your area would be a big factor in whether PPV would work for you.

    Overall, I think PPV is an excellent tactic under the right circumstances. Practice with it in different structures under different conditions to learn where it should and should not be used. Hope you have found this information helpful. Feel free to e-mail me if you have any other questions.

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    cmjones, Our Dept. has used PPV for ventalation for over 10 years and have trained in using it for fire attack, with great success. But we haven`t had the situation to use it during fire attack. I know Salt Lake City has been using it for fire attack for quit awhile. Your Dept. should train extensivly on old structures before using it. Using PPV at the wrong time or place can make a bad situation alot worse.It`s impresive when done properly. You`ll see alot of anti-ppv posts, but don`t let that stop you from seeing for yourself. You should be the judge. Chewy
    Lead,Follow or Get out of the way.

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    Good points by all. Our dept has used it for at least 10 years (as stated, mainly on residential fires, their effectiveness drops rapidly in large structures) with excellent results. Be careful when the fire's out or you're just clearing smoke from a pot-of-food on the stove job though, as we've found the co levels from the gas powered fans are a big problem...sometimes you're putting in more than you're taking out.

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    Our department has been using PPV for about 6 years. We like it, but as stated earlier training is a key element in it's use. If you don't know what you are doing, you can put one on the ground in a hurry. It's all about knowing what situation is good for PPV and what situation will be detrimental to interior attack personnel.

    dmleblanc had an excellent post with wonderful information. We trained with smoke on several instances and made sure all personnel were comfortable with PPV before changing our SOG's regarding it's use.

    PPV is a great tool in the arsenal. It greatly improves visibility and reduces heat. But like every tool, it has its place and you need to know its uses and limitations.

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    Be safe out there!!

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    PPV like every other tactic in the fire service has it's place. I have seen it used a few times in MA calls to a neighboring town that
    swears by it. On two occasions they have almost killed FF's from my dept. Once in a box factory with large piles of cardboard burning, the
    engine co. from my dept. had most of the fire knocked down then the fan was started up. It immediated flared up the fire intensely almost crispening the co. The Lt. went outside and put a hook in the fan breaking it. The second time an engine and ladder went to a basement fireand were at the cellar stairs attacking the fire. they heard that the fan was being pu in place so they were going to go outside and wait till after the fan was on to resume attack. Too Late!
    As they got to the first floor they had to dive down the cellar stairs because the fire came at them because the fire pushed through an opening in a first floor closet from the cellar. Almost killed them. In older areas of the country it is harder to use PPV due to balloon construction and multiple voids created by renovations as well as the abundance of old wood frame structures that will readily
    ignite. I'm not saying it is bad, just saying it isn't effective everywhere in every situation.

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    iceman4442
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    Good thread - lots of useful information.

    My department is in the process of evaluating PPV for initial attack, and we've done a few burns with it with varying results - due mainly to different construction types as one post mentioned. We were still experimenting with different size vents, this thread may have just saved us some time - thanks!

    Done correctly in the right circumstances, it looks to work very well!

    We don't have SOP's in place yet, but will likely soon.


    Stay safe!

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    "The Lt. went outside and put a hook in the fan breaking it"

    Another very professional action! I guess he couldn't figure out how to unplug or throw a switch? Almost died huh?

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    Hey Mike C, how would you like to MA to a town for every fire, go in and put it out only for them to do stupid s*** like that. Happens everytime due to their leadership's poor decision making. Very frustrating. Maybe not the smartest thing was done, but the officer reached the breaking point. Fire flared up really good, in a large warehouse with only one line and no vertical ventilation. You tell me.

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    Default Good post

    All good info.
    One thing that should be noted. In areas where buildings are older and are closely spaced, you should be careful of the bad air hole side.

    When PPV is used, like conventional ventilation, two holes are made. One for the good air and one for the bad air. The location of these two holes depends on the location of the fire. Normally you would want to place the bad air hole as close to the seat of the fire as possible. The good air hole would be farther away. If the fire is located in a rear room and the bad air hole is made at the rear (like it should) the amount of fire that initially comes out of that hole is like a blow torch when using PPV. If the area is congested with other hazards, like other buildings then this large amount of fire becomes a hazard to the other buildings and exposure protection.

    I don't have a problem with PPV in the attack mode, but many fire officers that I know don't have a good handle on conventional ventilation let alone PPV.

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    Those of you that say training and coordination are required, are right on target.

    PPV is great if used correctly, even during fire attack. But it has to be coordinated with fire attack and line placement. If used too soon, it could be disastorous. The hardest thing I face when using it is getting people to leave the @$#%@34 windows and doors alone. Tendency has it for them to want to open all windows and doors or the wrong ones. This has a tremendous negative impact on the process and thus gives the "non believers" the image that it "dont work"

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    The comments, opinions, and positions expressed here are mine. They are expressed respectfully, in the spirit of safety and progress. They do not reflect the opinions or positions of my employer or my department.

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    Captstanm1 makes a good point. If your department routinely breaks all the glass out of a structure to ventilate, as some departments do, it's a habit that needs to be broken if PPV is to work properly. Breaking glass to ventilate has its place, but if you're going to use PPV you need to keep the glass intact or the building won't pressurize. Understand that the fan does not merely create a breeze through the building, it actually creates a slight positive pressure within the structure, forcing the smoke, heat, and gases out. The enclosure of the building must be intact for it to work. Did I mention practice, practice, practice?

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    We have been using PPV for about 8 years. We believe in it and its a big part of our training. On initial attack, coordination is the key. The entry team and the RIT must be aware of what is about to happen. The safety officer must confirm that conditions and circumstances are right before the fan is started. The exhaust location(s) is very important.

    I think its the most effective change to interior attack that I've seen in my career.

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    Default a question

    Let me see if i understand this. you pull up to a good job (heavy smoke and fire present), you take the time to pull a fan, put it in the doorway and start the fan and put a good supply of additional fuel(air)in the building causing it to light up like a roman candle. This is a good thing? What happens to the floor above team when this happens? what happens to the outside vent team when entering to search for LIFE hazards after this happens? what happens to the guys on the line making an aggressive interior attach when this happens? Or do you not put a floor above team into the building until this happens, donot let your outside vent team enter to search for LIFE till after this happens, don't make an aggressive interior attach with the line till this happens? Just a couple of questions i need answered before i jump into this forum.

    bob g
    fdny rescue2

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    Bob,
    My dept doesn't use PPV, and we all know your dept doesn't either. I think that as a whole, FDNY fights fires in buildings that are too big to work with PPV. But if you have a house that is more or less sealed up except for the vents next to the fire, the PPV should push much of the crap out of the building. It makes conditions much more habitable in the building. If it works, its great, but you do have to change your tactics somewhat. There's too many questions for a volunteer dept if you ask me, but that's just me.

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    What happens to the floor above team when this happens? what happens to the outside vent team when entering to search for LIFE hazards after this happens? what happens to the guys on the line making an aggressive interior attach when this happens? Or do you not put a floor above team into the building until this happens, donot let your outside vent team enter to search for LIFE till after this happens, don't make an aggressive interior attach with the line till this happens?
    Sadly not everyone has 5 or 6 people per rig to man the door, have an OVM, etc.


    PPV I only encountered twice while a firefighter by one of our westside BC's who swore by it. I swore I saw him make foundations twice. However, like anything else, it must have its place. I do agree with RescueBob that introducing fresh air in a larger building is not a good idea but in smaller, tight houses I can see the logic.

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    Default another question

    OK how about this. Small three bedroom ranch. Livingroom and kitchen in the front, bedrooms in the rear. Fire in the kitchen extending into the livingroom. You mean to tell me that someplace in the USA someone is going to put a fan in the front door or front window of this place and introduce a whole lot of forced air into it before anyone has searched the rear bedrooms. PLEASE tell me that I am wrong.
    bob g
    fdny rescue2

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    Using PPVs is good in theory for certain situations. Although we train on it, I have yet to use one on a fire. Every house fire I've shown up at was too far gone (i.e. the fire made the exit hole too big).
    In order to work right, the building either has to be small enough, or you have to add fans. The fire has to be near a door or window (or other quickly made vent), or you will push it towards the exit hole. The fire cannot have already vented itself and made too large of an exit hole. The fan has to be behind your interior crews.
    One advantage is that it is less manpower intensive than using a truck company or two (which we unfortunately don't have) to vent a building.
    What a would give for a tower ladder and a few good truckies.

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    PPV works very well when implemented properly. You must have a well coordinated attack in place and direct communication between your attack sector and ventilation sector. Some of the posts looks, to me, like some people don't understand some of the priciples of ventilation. If the roof is burned through the house is already self ventilated. PPV will be ineffective. As far as search & rescue remember your priorities 1}Rescue 2} Evacuation 3) Ventilation 4)Attack, 5) Salvage... in that order. You can have several opeartions going on at the same time. Ventilation will remove smoke making visiblity better, will remove heat making tenabilty better especially for some one who is with out PPE. PPV is very easy to control as you can choose where you want the smoke to exit enableing you to direct smoke and gases away from rescue operations or attack operations. AS you can see by some of the posts if done incorrectly it can be very dangerous for all involved.
    If studied, practiced, and understood it is an invaluable tool.
    Have a great day.
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    we use ppv on every residental fire during initial fire attack. for those of you that have not tried it do not understand what crucial part of the arsenal this can be. if used properly with the correct ventilation you can do several things. first of all you are pushing cool air into the structure greatly lowering the temperature and possibly preventing a flashover, and making for much cooler working conditions. second with PROPER ventilation you can actually push the fire back into the room and limit spread. third visibility can be improved immensly with PROPER ventilation. try it you might like it. it does take proper placement of the fans outside the doorway, I suggest investigating it a little, and try it you will be suprised with the results.

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    rescue2bob,I hope I can clear this up a little for you.First you get your charged line in place,fan placed at the entry point,6-8'from the doorway, started but not operating into the structure, send your vent man to the kitchen window.Once everyone is ready,the window is taken out,the fan is directed into the structure.Wait a few seconds and begin your attack.All heat and smoke will be forced out of the opening. It will also create a venture affect and draw the heat and smoke away from the bedroom area,giving the occupants a better chance of survival. As stated in other posts, it takes coordination and training and is not the save all.Just another tool in our bag of tricks. Chewy
    Lead,Follow or Get out of the way.

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    PLEASE tell me that I am wrong.
    Resc2ueBob,

    It goes against traditional thought and I agree that it is somewhat questionable. Like I said - saw it twice and 2 foundations. However that was probably due to our Bat Chief who like to call his men his "Fire Suppression Force" instead of his firefighters. Oh well, everyone has a b-shift.

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    theboxalarm, What experience does your Bat Chief have with this method? Has your Dept ever trained on it? This isn`t something you read about in a magazine and then go out and try at your next structure fire. Just curious. Chewy
    Lead,Follow or Get out of the way.

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    Default Re: another question

    Originally posted by rescue2bob
    OK how about this. Small three bedroom ranch. Livingroom and kitchen in the front, bedrooms in the rear. Fire in the kitchen extending into the livingroom. You mean to tell me that someplace in the USA someone is going to put a fan in the front door or front window of this place and introduce a whole lot of forced air into it before anyone has searched the rear bedrooms. PLEASE tell me that I am wrong.
    bob g
    fdny rescue2
    G'day Bob,

    I would hope that they would put the fan at the back door and then make a smaller exit hole in the kitchen eg a window. Then it should work well if everything is coordinated correctly including the attack.
    Busy polishing the stacked tips on the deckgun of I.A.C.O.J. Engine#1

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    We have been through training and we have done this in drills, have not used at an actual call other than for ventilation purposes. When we drilled with it, we were impressed with how well it works when it is done correctly. If done incorrectly, it's impressive how bad things can get! It's like everything else, you need to know HOW to use it, WHEN to use it, and do it RIGHT.

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