The vertical thermal stratification observed within a room during summer nights refers to the measurable disparity in air temperature at different heights, specifically between the upper regions near the ceiling and the lower regions close to the floor. This phenomenon arises from the principles of thermodynamics, where warmer air, being less dense, tends to rise, and cooler air descends. An example would be measuring a temperature of 28C near the ceiling and 24C near the floor in an unmixed room.
This temperature gradient has significant implications for energy efficiency and occupant comfort. Understanding and mitigating this stratification can lead to reduced energy consumption for cooling, as thermostats are often placed at a specific height and may not accurately reflect the average temperature throughout the room. Historically, architectural designs in warmer climates have incorporated features like high ceilings and natural ventilation strategies to manage such thermal gradients and enhance passive cooling.