What is negative-pressure ventilation?

Negative-pressure ventilation refers to a technique used in firefighting to remove smoke and heat from a structure. This method creates a lower pressure area inside a building compared to the outside atmosphere, which causes smoke to be pulled out of the structure through controlled openings. By utilizing exhaust fans or other methods to create this pressure differential, firefighters can efficiently extract smoke, thus improving visibility and air quality for both the occupants and the responding personnel.

This technique is particularly valuable when used in conjunction with positive-pressure ventilation, where fresh air is introduced into the structure from an entry point. Together, these methods can significantly enhance the overall effectiveness of ventilation operations during firefighting efforts.