Which firefighting practice involves using ventilation to control smoke and heat?

Positive pressure ventilation is a firefighting practice that is used to manage smoke and heat by creating a pressure difference to force smoke and heat out of a structure, typically through openings such as windows or doors. This technique involves the use of fans to push fresh air into the structure, which not only helps to clear smoke but also improves visibility and makes conditions safer for firefighters while they work to extinguish the fire.

In this method, firefighters strategically set up fans at the entrance and allow the pressure generated by the fans to push smoke and hot gases out, often through designated ventilation points. This technique is particularly effective in large structures or where traditional methods of ventilation may be less efficient.

The other methods mentioned may have specific applications and benefits, but they do not focus on the positive pressure mechanism used to control smoke and heat in the same direct manner. For example, negative pressure ventilation pulls smoke out of the structure, which can be less efficient in certain situations. Controlled burn ventilation and cyclic ventilation have different objectives and applications in firefighting that do not primarily emphasize controlling smoke and heat via positive pressure.