Which two ventilation approaches are commonly used on the fireground, and what is each approach's purpose?

Which two ventilation approaches are commonly used on the fireground, and what is each approach's purpose?

• A. Natural ventilation relies on openings to move air.
• B. Mechanical ventilation uses turbines exclusively.
• C. Positive-pressure ventilation pushes fresh air into the structure to improve visibility; negative-pressure ventilation pulls air to exhaust smoke.
• D. Hydraulic hatch ventilation uses water jets.

Answer: (C)

Two ventilation approaches commonly used on the fireground are positive-pressure ventilation and negative-pressure ventilation. Positive-pressure ventilation uses a powered fan to push fresh air into the structure through an entry point. The purpose is to create positive pressure that forces smoke and hot gases out through existing openings, which improves visibility and creates safer conditions for interior teams. Negative-pressure ventilation uses a fan positioned to pull air out of the structure, creating lower pressure inside. This draws air in from outside through openings and exhausts smoke and heat, helping to ventilate spaces and make conditions more tenable for search and fire attack. If openings aren’t managed properly, positive-pressure ventilation can push smoke into other areas; negative-pressure ventilation requires controlled exhaust and intake points to avoid drawing smoke where it’s not wanted. Natural ventilation relies on openings and weather and isn’t an active, mechanical approach; other described methods that imply exclusive turbine use or water jet ventilation aren’t standard fireground practices.