What effect does proper ventilation have on the likelihood of backdrafts?

Proper ventilation significantly reduces the likelihood of backdrafts by allowing smoke and heat to escape from a compartment fire. A backdraft occurs when a fire, which has consumed most of its available oxygen, is suddenly introduced to fresh air, causing an explosive reaction. When firefighters properly ventilate a structure, they create an environment where the hot gases and smoke can vent to the outside, thus lowering the temperature and the buildup of unburned combustibles in the space.

By letting these products of combustion escape, proper ventilation helps to stabilize the atmospheric conditions within the building and decreases the chance of a sudden influx of oxygen leading to a backdraft scenario. This controlled removal of heat and smoke helps to maintain a safer environment for both firefighters and any trapped occupants, as it mitigates the risk of explosive flare-ups that are characteristic of a backdraft situation.