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Permalink Reply by Dave on June 17, 2008 at 10:08am

Wow, I guess i was right!! What i am surprised was the total CO amounts. Again chief...thanks for the info and the study results. Confined space is one area that we do use a Fan, and recently we switched to electric.

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Permalink Reply by Joe Alvarez on June 10, 2008 at 2:28pm

PPV has its place in the fireground .. it must be set up and ready once the seat of the fire is discovered by interior crews .. with confermation that there is no fire extension in the cockloft (attic).. roof operations are usually dangerous .. and should be sought early on scenarios such as trench cuts on strip malls and other common attics on the uninvolved area ... usually a fire will vent prior to working on the roof above the fire itself so it is an unecesary hazard ... if the fire has made head way already a defensive mode should be considered by command and reduce the threat of life to our fellow firefighters ..granted if the fire has vented the threats have been reduced but roof collapsed are always a great concern .. it all depends what type of roof construction we are talking about . ... and the time that is lapsed on the fire spread .

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Permalink Reply by Mike Davenport (COUCH) on June 10, 2008 at 3:09pm

First off, no two fires are alike, they all have the same attributes but behave differently depending on the layout, fuel load available, air availability, 3 dimensional traveling scenarios and more. Remember the main benefits of rooftop ventilation are survivability for trapped occupants, and the cessation of horizontal fire spread. Once the vent is made (never before) PPV is an unbelievable situation for helping control a fire scene, but treat it wrong.. vent before your attack lines are in place, forget to have your secondary water supply ready, or vent on the wrong side of the roof on a windy day and you will quickly be in a defensive posture instead of an active attack mode. So, what do I think? The best scenario is a combination of rooftop and PPV when rooftop access is a possibility but only for departments who have learned the techniques and practiced them til they puked, literally...

COUCH

Attachments:

• Rooftop Truckies.jpg, 96 KB
• Vent class - Lt. 1910.jpg, 442 KB
• Fort Dodge Hook and Ladder.jpg, 242 KB

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Permalink Reply by Dino1410 on June 14, 2008 at 11:34pm

ROCK ON!! Couch, I couldn't have said it better. I tried, but may have fell short.

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Permalink Reply by Joe Alvarez on June 10, 2008 at 5:31pm

If the seat of the fire is isolated by interior attack crews , and the attic is clear ... they are the ones to call for the fan ... granted command must survey this wish with smoke conditions and behavior from an outside perspective ... They have been exceptions when we are talking about multi gable single family dwellings ... were fire can go unchecked if a thorough inspection of the roof through out is not performed ...Down here we are very confident that we do have a larger amount of time to work with ... most of our construction is CBS in nature .. I am sure wooden frames are a different story and I am in not in any position to comment on those ... I do know that time is a very important factor , heat and flash over conditions are more readily common on wood frames .

Flash Over conditions should be accounted for , with experience at the nozzle , just how far in from your point of ingress and egress ... and are you making an effective contribution to cooling the area with out steam burning your crew..with the few times I have had wood frame fires I do know that they change much more rapidly and unless you arte very aggresive early on .. a defensive mode should be considered

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Permalink Reply by Joe Alvarez on June 10, 2008 at 5:42pm

Fans should never be turned on until interior crew have performed atleast a knock downon the seat of the fire .. and Isolated the fire to specific area .. to call for the fan with out knowing what is above you and to not know if there are spreads in the fire would be foolish and dangerous .. Positive pressure Ventilation has its purpose .. to improve visibilty , to regress the fire to freeburning phase .. and to eliminate smoke conditions and heat ... It also should be performed injunction with natural ventilation .. this means taking out the windows in the fire room from the outside to isolate and prevent the spread of fire to the uninvolved side .

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Permalink Reply by Dave on June 10, 2008 at 5:46pm

Joe...I agree 100%. In my expereience, Small kitchen fires and one room jobs with proper horizontal vent and a quick fire knockdown the room is cleared quickly of smoke. In my city using a fan before opening up to take a look and see if the fire has spread will be bad practice.

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Permalink Reply by Bobby Medders on June 10, 2008 at 9:11pm

I agree with Engineco913. If conditions are still safe enough to do so, then PPV along with a well placed hole in the roof can be a big help. Just make sure you don't start the fan too early, or else you'll feed the fire with your men/women still inside.

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Permalink Reply by roy yoder on June 11, 2008 at 12:42am

the object of good vent is to move the gases and fire back thru the burnt area and out of the structure into open air. there are many tools in our tool box (the engine truck ect.) i have been on jobs when the wrong tool was used with very bad results. it just goes to show that practice does not make perfect only perfect practice makes perfect. our first job is to save lives then property. me is the most important person on the scene, keep me safe and my training will take over to finish the rest. see above about practice. the next thing to look at is the different building and manpower (not picking on boston because we have a nearby city that responds 2 engines 1 ladder and a bat chief to a single family dwelling that is 14 guys. when this rural dept. goes we have 1 engine with 1 driver 1 tanker with 1 driver and hope someone else shows. for years we have averaged 6-7 men on a structure don't care what type.) we have done and train on about all the combos for vent. you don't take a monkey wrench to fix a watch if you want a watch. your local sop's will have a lot to say how you vent. alarm time travel time and level of training of manpower on scene and the amount of manpower all play a huge part as to what tool we choose to use. we have a county near here that if you have fire showing from one room you go to defensive mode and not enter the structure. needless to say they have plenty of parking lots. it takes about 3.5 to 4 min. to have a normal house room to flash. where is your station located to the fire and how many rooms have flashed till you get there an set up. if you have fire coming out of all the third floor windows is not this fire vented and if the ceiling is still there then a quick attack is all that is needed with good steam conversion and out the window the beast goes. i know each fire is different that is why you have your tool box full of tools and if you and all the rest of the crew don't know how to use that tool than leave it ALONE. it tends to hurt firefighters. ooooops.

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Permalink Reply by roy yoder on June 11, 2008 at 1:03am

thanks John Krista for the pat but these moments of revelation don't come without digging for info and going to sites like this along with other training and reflection to history of all our past fires and not being afraid of our best and our worst to be looked at for improvment. just got in from teaching a ventilation class to a new recruit class and will get an email off for the powerpoint. i don't mean to say that someone don't know what their doing but i have been on fully staffed paid, am presently paid as 1 driver 24 on 48 off with personnel that pay to fight fire showing up in peasonnel vehicles, and paying to be a vol. chief in the county. you better come with a lot of tools in your box and don't pull the wrong one out of the box. i did that on a relay pump setup with very bad results.

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Permalink Reply by Wes on June 14, 2008 at 1:13pm

I will have to say this has been a very active post for sure!! The thing is there seems to be many firefighters dead set against any ppv and thats wrong just because the way youve always done things works doesnt mean that you need to stick with it. There are many ways to vent a building and your way may work but that doesnt make it the best way nor either is ppv. But all of you who are dead set against trying anything new are getting yourselfs stuck in that rut that we all do sometimes, weve always done it this way so thats the way it is. You need to open your mind and try other things as I read earlier in this post train train train. Try everthing you can in training you might be suprised the amount of new ways you find to do things from the postion of your appratus to the way you load your hose.

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Permalink Reply by Irons38 on June 14, 2008 at 3:13pm

I think many good points have been made. There are pro's and con's for both. In my opinion I think in the near future you are going to see many departments that have always been strictly vent the roof start using PPV because of the "fire fighter killers " the truss roof. I know in my area many departments have pre planned not going to the roof and using horizontal ventalation (PPV).

Reading smoke is also a good tactic to use to determine the type of ventalation needed. If the roof is not a question then I would use it. My department has always used the roof but like I said earlier we are changing tactics with certain wood truss built residential and commercial properties.

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