The use of a fan to blow clean air into a structure and force fire gases out is known as ____ ventilation?

The use of a fan to blow clean air into a structure and force fire gases out is known as positive-pressure ventilation. This method involves using mechanical fans to create a higher pressure within the building compared to the outside environment. As a result, the increased pressure pushes the smoke, heat, and other fire gases out of openings, thereby improving visibility and creating a safer environment for firefighters and any potential victims inside.

Positive-pressure ventilation is particularly effective in reducing the overall temperature and smoke levels within a space, allowing for better conditions to fight the fire and perform rescues. This technique is frequently employed during structural firefighting operations to enhance the efficiency of the suppression efforts and improve the safety of the firefighting team.

Other ventilation methods, while useful, do not necessarily employ the same approach of creating artificial pressure within a structure to displace gases. For example, mechanical ventilation is a broad term that encompasses various methods of ventilating any space, not exclusively focusing on the creation of positive pressure. Horizontal ventilation typically refers to the practice of opening windows or doors to allow smoke and heat to escape laterally, rather than forcing air in. Ejection is not a standard term used in fire ventilation practices, making positive-pressure the most accurate answer in this context.