Which type of ventilation is typically used to expel heat, smoke, and gases?

Vertical ventilation is typically employed to remove heat, smoke, and gases from a structure during a fire response. This method involves cutting openings in the roof or high walls of a building, allowing the heat and smoke to rise and exit directly upward. Since smoke and hot gases naturally travel upwards due to their lower density compared to cooler air, vertical ventilation is particularly effective in quickly clearing these hazardous elements from the fire building.

This technique is strategically utilized to improve visibility and conditions for firefighters working inside the structure while also helping to lower the overall temperature, which can prevent flashover and create a safer environment for both occupants and responders.

In contrast, other ventilation types do not achieve this specific objective as effectively. For instance, horizontal ventilation involves removing smoke and heat through lower openings, which can lead to a build-up of hot gases at the ceiling level, potentially creating dangerous conditions inside. Depressurization ventilation is a method used primarily for smoke control in large spaces but does not target the removal of heat and gases directly in the same way that vertical ventilation does. Natural ventilation relies on wind and natural airflow, which is less reliable in controlling smoke and heat during an active fire situation.