Why register? ...To Enhance Your Experience
+ Reply to Thread
Results 1 to 11 of 11
  1. #1
    MembersZone Subscriber
    Join Date
    May 2000
    Location
    Lincoln, NE
    Posts
    195

    Default PPV and Carbon Monoxide

    Hello all...I did perform a search on this subject, but didn't "quite" find what I was looking for.

    Could anyone point me in the right direction of (or has anyone performed the research) the actual amount of CO pumped into a structure using gas fans? Even/especially with an exhaust tube placed on the fan to divert the fumes? I'm curious as to whether or not anyone has found the amounts of CO in the structure to be within the broad flammable limits (LEL/UEL) of Carbon Monoxide.


  2. #2
    EuroFirefighter.com PaulGRIMWOOD's Avatar
    Join Date
    Jul 1999
    Location
    UK
    Posts
    831

    Default

    You would need immense amounts, beyond the capability of a PPV blower I am sure, to reach the lower flammable limits of CO within a structure or compartment.

    The LEL for CO is around 12.5% and I have carried out some testing that shows PPV will raise CO to levels that might be harmful to humans over long periods as it exceeded 50ppm. You may well achieve higher levels under the right conditions. However, even at levels around 12,800ppm (1.2%) where death occurs within 2-3 minutes, you are way short of the LEL.

  3. #3
    MembersZone Subscriber
    Join Date
    Oct 2002
    Location
    The North East
    Posts
    489

    Default

    I've never thought of the LEL being the concern. We have limited our use of the PPV fan in occupied dwelling for minor smoke removal purposes. We were getting readings of 35-50 PPM with the fan and per our SOP anything greater than 9 PPM is considered "elevated". It is often a balancing act to decide how best to remove smoke from "food on the stove" or other minor issues.

  4. #4
    Forum Member nmfire's Avatar
    Join Date
    Nov 2002
    Location
    Maryland (DC Suburb)
    Posts
    5,738

    Default

    If you can manage to blow up a house by filling it with CO from a PPV fan's little lawnmower engine to the point of it reaching LEL, I will be very impressed. I don't know what the PPM of CO would be to reach LEL but I don't think it is remotely close to what that thing can produce if you let it run all day. I think the hazzard to humans breathing it would be far greater. Anything over 12ppm is ventilation for us. Anything over 75ppm is SCBA for us. Using the gas fan without the exhaust tube, you will never get it down. Using the tube can work if the tube is downwind.

    For normal CO and light smoke from cooking, we just use two stacked electric fans and be done with it.
    Even the burger-flippers at McDonald's probably have some McWackers.

  5. #5
    Forum Member DeputyChiefGonzo's Avatar
    Join Date
    Aug 2000
    Location
    Somewhere between genius and insanity!
    Posts
    13,556

    Default

    What is one of the major fire gasses found in a building duing overhual ops?

    CO.

    What is the building full of?

    CO.

    Do someone really think that the output of CO from the one to two cylinder internal combustion engine of a PPV fan is going to add any more CO into the building, especially with the 20+ MPH speed of the air rushing through the vent openings?

    I can see another position on the ICS/NIMS chart under "operations"....

    PPV CO monitoring officer...
    ‎"The education of a firefighter and the continued education of a firefighter is what makes "real" firefighters. Continuous skill development is the core of progressive firefighting. We learn by doing and doing it again and again, both on the training ground and the fireground."
    Lt. Ray McCormack, FDNY

  6. #6
    MembersZone Subscriber
    Join Date
    Nov 1999
    Location
    Connecticut
    Posts
    1,017

    Default

    Quote Originally Posted by CaptainGonzo
    I can see another position on the ICS/NIMS chart under "operations"....PPV CO monitoring officer...
    At TOPOFF last year we had OSHA inspectors measuring CO near the exhaust of gasoline power units, outside, with a steady breeze.
    -------------------
    "The most mediocre man or woman can suddenly seem dynamic, forceful, and decisive if he or she is mean enough." from "Crazy Bosses"
    -----------------------------------------------
    Genius has its limits, but stupidity is boundless.

  7. #7
    Forum Member FyredUp's Avatar
    Join Date
    Jul 1999
    Location
    Rural Wisconsin, Retired from the burbs of Milwaukee
    Posts
    9,663

    Default

    There are 2 solutions to the introduction of CO into the building via PPV.

    1) Put an exhaust extension on the motor to move the exhaust away from the intake side of the fan. (although as stated during a fire attack or overhaul this problem is virtually non-existant due to CO from the fire in the building)

    2) Use an electric PPV fan. They do make them. Not the old style smoke ejector, but an actual electric PPV fan.

    The only time CO is a problem is when you are using a gasoline powered PPV fan to remove odors or smoke from burnt food. Not during an actual fire.

    FyredUp

  8. #8
    MembersZone Subscriber
    Join Date
    May 2000
    Location
    SW MO
    Posts
    4,249

    Default

    Benefit analysis... God knows how much CO due to the fire conditions compared to the very few ppm you'll get from a PPV fan. Not to dispute anyone's findings from tests, but 50 ppm sounds aweful high for a little fan motor, especially when it's moving 15,000+ cfm. However, it makes me curious now and I'm going to have to try it for myself.

  9. #9
    the 4-1-4 Jasper 45's Avatar
    Join Date
    Dec 2002
    Location
    ...A great place, on a Great Lake
    Posts
    2,783

    Default


    I can see another position on the ICS/NIMS chart under "operations"....

    PPV CO monitoring officer.


    Now, the really important issue here is deciding what color vest to assign this vital position.

  10. #10
    Forum Member fireman4949's Avatar
    Join Date
    Oct 2005
    Location
    Tallahassee, Florida
    Posts
    2,323

    Default

    Quote Originally Posted by jasper45
    Now, the really important issue here is deciding what color vest to assign this vital position.
    Hmmm...How about "cherry red"?




    Kevin
    Fire Lieutenant/E.M.T.
    IAFF Local 2339
    K of C 4th Degree
    "LEATHER FOREVER"
    Member I.A.C.O.J.
    http://www.tfdfire.com/
    "Fir na tine"

  11. #11
    Forum Member nmfire's Avatar
    Join Date
    Nov 2002
    Location
    Maryland (DC Suburb)
    Posts
    5,738

    Default

    i should have mentioned in my response that it was all in regards to venting CO Or light smoke, not PPV for fire attack. Clearly, the house being on fire will produce about a billion times more CO than the lawnmower engine at the front door.
    Even the burger-flippers at McDonald's probably have some McWackers.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. PPV ventilation
    By WASIE205 in forum Firefighters Forum
    Replies: 2
    Last Post: 06-02-2001, 11:59 AM
  2. using a PPV fan
    By WASIE205 in forum Firefighters Forum
    Replies: 8
    Last Post: 05-31-2001, 01:05 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts