What phenomenon is described by the stack effect?

The stack effect refers to the movement of air into and out of buildings, driven by temperature differences within the building and the external environment. When the indoor air is warmer than the surrounding outdoor air, it becomes less dense and rises. As the warm air rises, it creates a negative pressure at lower levels, which draws in cooler air from outside through cracks, openings, or ventilation systems.

Understanding the stack effect is crucial in building performance because it influences heating and cooling efficiency, indoor air quality, and energy use. This phenomenon is especially significant in taller buildings where the temperature difference can be more pronounced, resulting in greater air movement. Effective management of the stack effect can improve energy efficiency and reduce heating and cooling costs, leading to better overall building performance.