Ventilation (firefighting)

Poorly placed or timed ventilation can increase the fire's air supply, causing it to grow and spread rapidly.

Their names refer to the general locations of the intended exit points of the heat and smoke to be ventilated.

The goal of each is to clear heat and smoke to increase chances of survival for trapped occupants, and/or so that water lines can be advanced into the structure, to more effectively battle the flames.

While their goals are similar, their applications are different; both require good timing and coordination so that increased air flow through a structure doesn't contribute to fire spread.

High-rise buildings sometimes also incorporate fans to produce a positive pressure in stairwells and elevator shafts to reduce smoke infiltration into those spaces.