172. Why is it necessary to secure the forced ventilation to a compartment where there is a fire?

Securing forced ventilation limits fire intensity and spread by preventing additional oxygen from reaching the fire; fire requires oxygen, fuel, and heat, and ventilation systems can inadvertently supply oxygen, intensifying combustion. Firefighting practice prioritizes securing ventilation to control the fire, not primarily for smoke removal or carbon monoxide smothering, and ventilation is run only with specific, controlled smoke-extraction systems.