The dangers of Vent-Enter-Search
Some are advocating the addition of an "I" into the equation, calling is VEIS or vent, enter, isolate, and search
Vent-Enter-Search (VES) is a strategic operational modality, the aim of which is to provide for rapid searches of areas remote from the fire in a given structure. The argument is that it is faster to ladder and enter many times than it is to work through a house to the victim.
VES as a strategic modality is not inherently wrong, but — and it's a big but — it is extremely dangerous and should only be used when absolutely necessary. Our primary life-saving tool is water and all other strategies and tactics are subordinate to that.
Whenever you perform this strategy you open yourself to the risk of completing a flow path that uses the window you just ventilated as its exhaust point.
The problem is that you cannot know what the inside of the house looks like, which doors are open, what other windows are open, etc. You cannot predict in advance whether the window you open is the one the fire was waiting on to grow explosively.
It is true that modern furnishings present more dense fuel packages. Given sufficient oxygen they will release tremendous amounts of heat energy.
We know before we break a given window that additional oxygen will be made available. What we don't know is whether that window is the one that allows enough to make for explosive fire growth.
Most fires in residential structures are ventilation limited. This is true precisely because of the density of the fuel packages. These fires are so ventilation limited in fact that they are often deceptive.
We tend to believe that breaking a few windows always makes things better, but venting a few windows and opening a few doors does not let in enough oxygen to take the fire from ventilation limited to fuel limited.
So what happens is you open the door and fresh air rushes in and the fire takes advantage of that oxygen and grows. Then you open a window or two and the fire takes advantage of that oxygen and it grows some more.
However, in order to make the fire fuel limited — that is to give the fire all the oxygen it can use — you would have to start opening up entire walls.
What this means is that almost every time you create an opening in a residential structure you are also introducing the possibility of extreme fire growth, even if "a bunch" of the windows are already opened. The fire grows quickly and unpredictably.
This simple fact of chemistry and physics has a profound impact on how we should re-evaluate our VES practices. Some are advocating the addition of an "I" into the equation, calling is VEIS or vent, enter, isolate, and search.
In this case, isolate means to first find the interior door to the compartment you intend to search before you begin the search.
Many of us have been talking about that for years while still referring to the strategy as VES. It is time to update the acronym.
We must also remember that the single quickest way to have an immediate impact on life safety is with the rapid application of water streams.
How those streams are applied (straight stream or fog) and where those streams are applied (from the interior or from the exterior) is less critical than the rapidity of the application.
If the people are trapped they are trapped because the structure is on fire, the fire is ventilation limited, and it will take time for firefighters to fight their way through a structure to them.
By applying an updated VES model, V-E-I-S, and by ensuring the rapid application of cooling streams, firefighters maximize the survivability of still viable victims, while limiting their exposure to extreme fire behavior.
However, even VEIS without water application continues to be one of the most dangerous strategies firefighters can employ and arguably should only be used when absolutely necessary to save a life.