Characteristics of thermal stratification and its effects on HVAC energy consumption for an atrium building in south China

More and more public buildings have functional zones without physical partitioning, and non-uniform thermal environments often exist inside it. Understanding this phenomenon and its influences on HVAC energy consumption is of great significance. Field measurements were carried out on a transport station in Nanjing, South China during daytimes, and thermal stratifications were found to be evident in the non-air-conditioned atrium with the linear gradients being range of 0.06-2.0 & DEG;C/m. An energy model coupled with CFD model is developed and verified by measured data. Further simulations are performed under cases of atrium height, glazed-roof material and season. The results show that the CFD simulated convective heat transfer coefficients of inner surfaces (CHTCIS) of the atrium vary according to scenario; linear temperature gradients differ by cases, and specifically there are two gradients in hot summer with the dimensionless interface heights being approximately 0.56-0.6; the HVAC loads of the airconditioned zones are estimated to be 115-146 W/m2 when adopting thermal stratification and user defined CHTCIS, and larger than that when no thermal stratification and built-in CHTCIS. The double low-e 6 mm plane glass contributes to the most favorable temperatures in both cold winter and hot summer, followed by the smallest HVAC loads. (c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

An increasing number of public buildings have functional zones without physical partitioning, leading to non-uniform thermal environments. Understanding the influence of this phenomenon on HVAC energy consumption is of great significance.