What does the phrase "stack effect" describe?

The phrase "stack effect" describes the natural movement of air within a building that occurs due to temperature differences between indoor and outdoor air. This phenomenon happens when warm air rises because it is lighter than cooler air. As the warm air ascends, it creates a negative pressure at lower levels, drawing cooler air into the building from outside. This can be particularly noticeable in taller buildings, where the height amplifies the temperature-induced pressure differences.

Understanding the stack effect is crucial for building analysts as it affects heating, cooling, and overall energy efficiency in structures. It also has implications for indoor air quality and ventilation strategies, which are essential factors to consider in the design and maintenance of buildings.