Which type of ventilation relies on natural air movements to remove contaminants from a structure?

Natural ventilation is defined by its use of natural air movements, such as wind and thermal buoyancy, to facilitate the exchange of air within a structure. This method allows fresh air to flow in while simultaneously pushing stale air, smoke, and other contaminants out through openings such as windows, vents, or doors.

In contrast to mechanical or forced ventilation, which depend on powered systems to circulate air, natural ventilation is driven purely by the environment. This type of ventilation is particularly effective in certain situations, such as smoke removal after a fire or in structures where it is impractical or impossible to deploy mechanical systems. Understanding natural ventilation is crucial for firefighters and emergency responders, as it can significantly influence the safety and effectiveness of operations during incidents involving confined spaces and smoke control.