Positive-pressure ventilation uses which component?

• A. The use of a fan to blow clean air into a structure and force fire gases out.
• B. Passive ventilation through openings without fans.
• C. Ventilation using water mist.
• D. Natural draft only.

Answer: (A)

Positive-pressure ventilation relies on a mechanical blower to push air into the structure. The essential component is a high-volume fan that delivers clean air inside, raising interior pressure. That positive pressure makes smoke, heat, and gases move toward exhaust openings or venting paths, improving visibility and reducing hazard for occupants and firefighters. This is what distinguishes PPV from passive ventilation, which relies on openings without a fan, from water mist methods that are for cooling or suppression, and from natural draft which depends on heat differences rather than a mechanical air source.