“Ventilation Control” Tactical Ventilation

      It’s funny to me that we have been fighting fire since it was discovered by man and yet every week I learn something new. I know that the laws of physics haven’t changed. I believe it is the unbelievable amount of technology we have at our fingertips. One of the things I learned early in my career was that a fire will be either fuel or ventilation controlled. The control of the ventilation (air feeding the fire) is done by opening the structure in a systematic and controlled manner. In the old days neighbors would open all the doors and begin removing the structures contents. They would have probably been better off closing the structure to force the fire to run out of oxygen.

     Let’s look at ventilation control. There are many small training props you can build to demonstrate this with live fire. If you do your research this is a great tool. Please be sure to do this demonstration outside and wear proper PPE! Modern structure fires will often go into a ventilation controlled condition. The newer structures are generally sealed tighter and people tend to leave windows closed. When the contents burn they produce a large amount of carbon monoxide and other gasses. They also lower the oxygen level needed to support combustion. When we arrive, we open the door to initiate a fire attack. By making entry we have also provided ventilation. The introduction of air into this heated/fuel laden atmosphere can quickly change the interior conditions. When studies have been done the temperature of the interior will rapidly increase and can result in a flashover before the firefighters have achieved extinguishment.

     As I have stated in the past, the introduction of water into this environment will likely cool this atmosphere. Another item that I have begun to see used is a door curtain. This device is installed in the entry point and effectively closes the opening but will still allow the firefighters a means of egress. I have seen teams cut a lower corner out of the door to allow the hose to be advanced with the door closed. My problem with this is the fact you have restricted the egress of the interior attack crew.

Training Objectives

     Upon completion the firefighter should be able to….

     • Discuss the control of fire by fuel/ventilation.

     • Identify the fire flow path through a structure.

     • Determine the best way to enter a structure without introducing a large flow of air into the structure.

     Scott Meinecke is a member of the Sheldon Volunteer Fire Department, an instructor for the Iowa Association of Electric Cooperatives, and field staff for the Fire Service Training Bureau. He can be contacted by email  smeinecke@iowarec.org