A CFD-CONTAM-BES framework incorporates wind pressure, air temperature, and indoor air circulation to estimate energy consumption of high-rise buildings

Urban high-rise buildings significantly alter wind circulation, solar radiation penetration, and heat accumulation, which in turn impacts their natural ventilation (NV) and energy performance. However, conventional building energy simulation (BES) often oversimplifies these interactions by modeling isolated buildings, ignoring the surrounding microclimate conditions. To address these limitations, this study proposes a framework combining computational fluid dynamics (CFD), multi-zone airflow modeling (CONTAM), and BES. This framework provides high-resolution, transient wind pressure coefficients (C_p), outdoor meteorological data, and indoor air circulation for BES to estimate cooling energy (CE) demands under NV and mechanical ventilation (MV). The applicability of the framework was evaluated by comparing the CE of an isolated residential high-rise building with that of buildings within six building clusters. The comparison revealed significant differences in the surrounding microclimate conditions, NV rates, and CE between the clustered buildings and the isolated building, as well as among individual units across different floors and even within the same floor. Overall, buildings in clusters exhibit NV rates up to 91% lower than those of isolated buildings. Furthermore, surrounding buildings can reduce CE by up to 40.2% under MV and 81.3% under NV by shielding the target building from solar radiation and wind. Correlation analysis identified C_p and exterior wall temperature as the dominant CE factors under NV and MV, respectively. These findings highlight the importance of a CFD-CONTAM-BES framework to incorporate the surrounding microclimate conditions, accurate C_p, and multizone air circulation for BES of buildings in urban areas.