What two forces cause smoke to pressurize inside a building?

The correct answer highlights the relationship between convection heat and smoke volume in creating pressurization of smoke within a building.

Convection heat is the process by which warmer air rises due to its lower density, leading to the upward movement of heat and smoke. As a fire burns, it generates significant heat, which causes air to expand and move upward, creating a pressure differential. This differential drives the smoke upwards and can lead to the accumulation of smoke in upper portions of the structure.

In conjunction with smoke volume, which refers to the amount of smoke produced relative to the space it fills, this upward movement can result in significant smoke pressure. As the volume of smoke increases, it occupies more space and contributes to pushing against any available openings, potentially leading to the smoke spilling over into adjacent areas.

Understanding the dynamics between convection heat and smoke volume is crucial for fire safety and incident management, as it informs strategies for ventilation and smoke management during operations.