Tactical Ventilation or Isolation of The Fire
One of the main risks of a fire is the smoke: it carries heat and poisonous gases, and obscures vision. In the case of a fire in a closed location (building), two different strategies may be used: isolation of the fire, or ventilation.
Paul Grimwood introduced the concept of tactical ventilation in the 1980s to encourage a better thought-out approach to this aspect of firefighting. Following work with Warrington Fire Research Consultants (FRDG 6/94) his terminology and concepts were adopted officially by the UK fire services, and are now referred to throughout revised Home Office training manuals (1996–97).
Grimwood's original definition of his 1991 unified strategy stated that, "tactical ventilation is either the venting, or containment (isolation) actions by on-scene firefighters, used to take control from the outset of a fire's burning regime, in an effort to gain tactical advantage during interior structural firefighting operations."
Ventilation affects life safety, fire extinguishment, and property conservation. First, it pulls fire away from trapped occupants when properly used. It may also "limit fire spread by channeling fire toward nearby openings and allows fire fighters to safely attack the fire" as well as limit smoke, heat, and water damage.
Positive pressure ventilation (PPV) consists of using a fan to create excess pressure in a part of the building; this pressure will push the smoke and the heat out of the building, and thus secure the rescue and fire fighting operations. It is necessary to have an exit for the smoke, to know the building very well to predict where the smoke will go, and to ensure that the doors remain open by wedging or propping them. The main risk of this method is that it may accelerate the fire, or even create a flashover, e.g., if the smoke and the heat accumulate in a dead end.
Hydraulic ventilation is the process of directing a stream from the inside of a structure out the window using a fog pattern. This effectively will pull smoke out of room. Smoke ejectors may also be used for this purpose.
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Famous quotes containing the words isolation and/or fire:
“The only happy talkers are dandies who extract pleasure from the very perishability of their material and who would not be able to tolerate the isolation of all other forms of composition; for most good talkers, when they have run down, are miserable; they know that they have betrayed themselves, that they have taken material which should have a life of its own, to dispense it in noises upon the air.”
—Cyril Connolly (1903–1974)
“The Laws of Nature are just, but terrible. There is no weak mercy in them. Cause and consequence are inseparable and inevitable. The elements have no forbearance. The fire burns, the water drowns, the air consumes, the earth buries. And perhaps it would be well for our race if the punishment of crimes against the Laws of Man were as inevitable as the punishment of crimes against the Laws of Nature—were Man as unerring in his judgments as Nature.”
—Henry Wadsworth Longfellow (1807–1882)