What does PPV stand for in fire service ventilation?

• A. Negative pressure ventilation.
• B. Passive ventilation.
• C. Pulsed ventilation.
• D. Positive Pressure Ventilation.

Answer: (D)

PPV stands for Positive Pressure Ventilation. The technique uses a powered fan to push air into the structure, creating higher pressure inside than outside. That positive pressure causes smoke, heat, and gases to move toward exterior exhaust openings, while bringing in fresh air to aid occupants and firefighters and improve visibility and conditions for interior work. It’s different from negative pressure ventilation, which pulls smoke out by creating a lower pressure inside; it isn’t passive (which relies on natural openings), nor is it pulsed (which would imply intermittent rather than continuous pressurization).