When smoke thins after opening a door, but still fills the doorway, the fire is probably located at what level?

When smoke thins after opening a door but still fills the doorway, it indicates a specific fire behavior under certain conditions. In this scenario, the presence of smoke at the doorway suggests that there is a product of combustion occurring on the same level as the fire.

Typically, smoke rises as it is a result of hot gases, and when we notice that the smoke is still present in the doorway, it demonstrates that the fire is not at a higher elevation, as the smoke would have risen above and thinned if that were the case. Instead, the thinning of the smoke implies that it is not as dense further above the door, suggesting the origin of the fire is likely below the door level.

This understanding of smoke dynamics is critical when performing fire operations, as it helps to assess where the fire may be located and guides firefighters on how to tactically approach the situation. By recognizing these nuances in smoke behavior, firefighters can make better decisions for ventilation and attack strategies.