How fast does it take for a room to fill up with smoke?

The time it takes for a room to fill with smoke can vary significantly based on several factors, including the size of the room, the source and intensity of the fire, ventilation, and the materials burning. In general, a small room can become filled with smoke in just a few minutes if a fire is actively burning. However, in larger or well-ventilated spaces, it may take longer for smoke to accumulate. It's crucial to evacuate quickly when smoke is present, as it can lead to reduced visibility and respiratory hazards.