Name two methods of positive pressure ventilation (PPV) used at interior fire scenes.

• A. A dedicated PPV fan to push clean air into the hazard area and door/opening pressurization to push smoke away from egress.
• B. Opening all exterior doors to ventilate the building.
• C. Ventilating by rotating fans random.
• D. Using water sprays to vent smoke.

Answer: (A)

Positive pressure ventilation works by creating higher pressure inside the fire area than outside, which pushes smoke and heat toward exhaust paths and clears the space for firefighters and occupants. The two PPV methods used at interior fire scenes are: first, a dedicated PPV fan that blows clean air directly into the hazard area, building pressure and driving smoke toward approved exhaust openings; second, door or opening pressurization, where air is blown in through an exterior door or opening to raise interior pressure and push smoke away from egress routes. These methods provide controlled airflow and improved visibility and safety. Opening all exterior doors, rotating fans randomly, or using water sprays are not PPV methods and can lead to uncontrolled flow or are unrelated to ventilation.