Which structural feature may cause a fire to become ventilation limited and increase the fuel content of the smoke?

High ceilings can cause a fire to become ventilation limited due to the increased volume of air in the space, which allows for a greater accumulation of heat and smoke. As the fire burns, it consumes the available oxygen, and with a higher ceiling, it may take longer for fresh air to enter the space compared to a room with lower ceilings. This can lead to a situation where the fire reaches a point where it is starved for oxygen, preventing it from burning effectively.

As a result, the smoke can accumulate and become more fuel-rich, as the incomplete combustion of materials takes place. The heat and gases produced can rise to the ceiling and spread horizontally, creating a thick layer of smoke with a higher concentration of unburnt particles. This is particularly dangerous, as it can lead to conditions that may ignite or produce flashover when additional oxygen is introduced, such as during a ventilation operation.

In contrast, atriums, windows, and metal roof decks don't contribute in the same way to creating a ventilation-limited scenario. Atriums, while they can affect fire dynamics, typically provide vertical openings that can enhance ventilation instead of limiting it. Windows can serve as openings for smoke to escape, helping to alleviate some of the pressure created by heat buildup. Metal