"Positive pressure ventilation (PPV) is a topic worthy
of some discussion. Ladder companies that carry PPV fans must be well versed in their use. There is a tendency that if someone sets a PPV fan at the front door, it should be started and run. This is not always the case. PPV fans are excellent tools for removing smoke from a dwelling, but should not be used prior to the fire’s
full extinguishment. While companies are still checking for pockets of hidden fire is not the time to fire up the fan! The influx of air forced into the dwelling can rapidly cause a small hidden fire to exponentially and violently appear to the forces inside. Like many fire departments’ actions these days, the results of improper PPV fan usage are easy to find on the Internet and should be viewed as
a training tool for all members. Just because the ladder company member places the fan in the doorway does not mean that it should be started! There has been such great recent discussion about wind effects on fire of late. If we fire up a PPV fan at the wrong time, we can be creating the same effects as a wind impacted fire." Pg. 208, Chapter 19.
Ventilation is always a topic of passionate discussion in the fire service today but it is usually centered on natural ventilation. Specifically, when do we take windows, flow path, forcible entry, etc. and not the tools most Truck Companies carry like the PPV or Exhaust fan. The knowledge and competence we demand of our firefighters regarding fire behavior should be equal to when and how to implement the tools that can have the same drastic impact on the volume and spread of fire.
A couple of questions for the kitchen table this Sunday:
1. Do you use PPV or exhaust fans?
2. If so, why do you use these tools?
3. If not, why do you not utilize them?
4. What do you utilize to assist in ventilation?
5. Under what conditions would you utilize these tools on the fireground?
Thanks for sharing!