When should you not use PPV fans?
PPV fans can only work as a fire rescue tool if only two openings exist in a structure. They should not be used when a structure is fully involved. They are best used for removing smoke from a room or structure when there are no longer extreme heat conditions present and no threat of flashovers.
What is positive pressure attack?
Positive Pressure Attack – The use of a high powered fan to control the flow of products of combustion, prior to fire control, with the intent of providing increased visibility and tenability for firefighters and potential occupants while fire suppression efforts are underway.
How does positive pressure ventilation fan work?
This positive pressure pulls the smoke and heat inside a compartment and moves it out of the controlled ventilation exit with the air being forced through the front ventilation opening. It is critical that there be only one entrance for the ventilation unit and only one exit for the removal of smoke and heat.
When would you use a negative pressure ventilation fire?
Exhaust fans or smoke ejection fans use negative pressure to remove smoke from a structure during firefighting efforts. Ventry Fans are designed for positive pressure ventilation (PPV) and attack (PPA). Positive pressure is simply more effective than negative pressure for aggressive, coordinated attack.
What are three incident priorities when performing tactical ventilation?
Decisions on the emergency incident are reached as incident managers consider three main incident priorities: Life Safety (both the occupants and the responders), Incident Stabilization and Property Conservation.
How do you set up positive pressure ventilation?
Typically, a PPV fan is placed about 1.2 m to 3.0 m (4 ft to 10 ft) outside the doorway of the structure. It is positioned so that the “cone of air” produced by the fan extends beyond the boundaries of the opening. With the doorway within the cone of air, pressure inside the structure increases.
What is the difference between positive pressure attack and positive pressure ventilation?
Positive Pressure Attack (PPA) is a coordinated fire attack where fans are used to assist in controlling the fire. Positive Pressure Ventilation (PPV) is the use of fans to remove the products of combustion after fire control.
What is the goal of positive pressure ventilation fire fighting?
Positive pressure ventilation (PPV) is a ventilation technique used by the fire service to remove smoke, heat and other combustion products from a structure. This allows firefighters to perform tasks in a more tenable environment.
What is a disadvantage of positive pressure ventilation?
Among the potential adverse physiologic effects of positive-pressure ventilation are decreased cardiac output, unintended respiratory alkalosis, increased intracranial pressure, gastric distension, and impairment of hepatic and renal function.
Which statement about tactical ventilation is most correct?
Which statement about tactical ventilation is MOST accurate? Tactical ventilation can be combined with fire attack to stabilize an incident. Tactical ventilation reduces fire damage in structures and limits water damage because it: increases speed with which interior fires can be extinguished.
What are 3 reasons for performing ventilation at a structure fire?
Rapid extinguishment reduces water, heat, smoke damage.
What is the goal of positive pressure?
What is positive pressure ventilation in a fire?
This pressurization or positive pressure ventilation (PPV) tactic can assist in the venting of smoke and high temperature combustion products and make attacking the fire easier than without PPV. However, this tactic also provides additional oxygen to the fire and can increase the rate of heat and energy being released.
How does PPV work in the initial stage of attack?
In utilizing PPV we must be 100% coordinated between the attack crew and vent crew 100% of the time. The end result of an uncoordinated use of PPV could be fatal and has been proven to be dangerous. So, how does PPV work as a tactic in the initial stage of attack? We must first have a very good idea where the fire is located.
Can PPV fans increase the effectiveness of fire fighters in high-rise buildings?
The measurements taken during the experiments included differential pressure, air temperature, carbon monoxide, metrological data and sound levels. PPV fans utilized correctly can increase the effectiveness of fire fighters and survivability of occupants in high-rise buildings.
What is a PPV fan used for?
Hidden fire and the introduction of a PPV fan can be a deadly combination for interior firefighters Today, most fire trucks are equipped with a positive-pressure ventilation fan. This tool has been in the fire service for quite some time and is used for ventilation tactics at structure fires.