Influence of Local Wind Pressure Coefficients Based on Height-Varying Reference Wind Speed on Building Energy Performance in a Dense Urban Environment
Abstract
EnergyPlus AirflowNetwork (EP-AFN) calculates external node pressure using opening height wind speeds, whereas wind pressure coefficients based on a fixed-reference wind speed (Cpr) are commonly used in building energy simulations. To address this inconsistency, this study used computational fluid dynamics to derive wind pressure coefficients based on opening height wind speeds (Cpl) and implemented them as opening-resolved EP-AFN inputs for two high-rise office buildings. Isolated, Interference, and Urban configurations were examined; the latter two models were compared for airflow and energy performance with and without natural ventilation. Cpl − Cpr differences were more pronounced at lower heights. Under identical Urban conditions, Cpr yielded lower air change rates and heating primary energy consumption than Cpl, with the largest differences on the lower floors. The Interference model showed nearly symmetric Cpl distributions, whereas the Urban model showed irregular distributions. Compared with the Interference model, the Urban model showed lower infiltration and ventilation rates without and with natural ventilation, respectively. The counterfactual comparison showed that the wind-pressure pathway reduced heating primary energy consumption, whereas the shading pathway increased it by reducing solar gains. The net heating response therefore varied with building and floor. These findings highlight the value of an integrated simulation framework with opening-resolved Cpl inputs for evaluating how airflow rates and solar shading shape floor-dependent energy use patterns.