Which type of pressure ventilation is used to exhaust a contaminated atmosphere from a structure?

Negative pressure ventilation is employed to exhaust a contaminated atmosphere from a structure effectively. This method works by creating a vacuum inside the enclosure, which allows air from outside to be drawn into the building through any available openings. As the outside air enters, it carries away the contaminants, smoke, or heat, effectively purging the space of hazardous substances.

This approach is particularly beneficial in firefighting and rescue operations, as it enhances safety for both victims and responders by improving air quality and visibility in a smoke-filled environment. By utilizing negative pressure, responders can create a more controllable atmosphere, allowing for better maneuverability and efficiency in addressing the emergency situation.

In contrast, other forms of ventilation might inadvertently introduce additional contaminants or fail to adequately remove hazardous materials from the area. Understanding the mechanics and appropriate applications of negative pressure ventilation is crucial for effective emergency response.