Vertical Thermal Stratification in Large Buildings: Analyzing the Influence of Building Height, Internal Heat Sources, and Climatic Conditions

The thermal assessment of large building requires a deep analysis of the indoor temperature according to the building height, internal gains and climatic conditions. Thermal stratification of the air in indoor environments is a phenomenon that can impact the comfort of the occupants. This study is dedicated to the thermo-aeraulic modeling of a large-volume building, aiming to proactively predict its response to three critical conditions: the incorporation of variations of building height, internal gains and external climatic conditions. Such large volume buildings are typically characterized by expansive internal spaces and intermittent, high-density occupancy, making interior thermal stratification a prevalent source of discomfort. Utilizing natural ventilation, a temperature contrast of around 7 ℃ was noted between 8 a.m. and 12 p.m. Subsequently, this contrast expanded to approximately 9 ℃ by 4 p.m. and eventually peaked at approximately 10 ℃ at midnight. In this context, our research introduces a zonal thermo-aeraulic modeling approach that integrates dynamic thermal simulation tools, TRNSYS and CONTAM, to address this phenomenon.