A holistic framework to utilize natural ventilation to optimize energy performance of residential high-rise buildings

A novel holistic framework was established using Building Information Modelling (BIM) to estimate accurately the potential of natural ventilation of residential high-rise buildings. This framework integrates Computational Fluid Dynamics (CFD) simulation, multi-zone-air-flow modelling, and Building Energy Simulation (BES) to calculate ventilation rates under the mechanisms of wind-, buoyancy- and wind and buoyancy-driven ventilation. The framework was applied to a 40-storey residential building in Hong Kong for estimating the potential of natural ventilation in residential high-rise buildings. The results show that the building can save up to 25% of the electricity consumption if the building employs wind-driven natural ventilation instead of mechanical ventilation. The electricity consumption can be further reduced up to 45% by facilitating the buoyancy-driven natural ventilation. However, natural ventilation is found to be effective only if the temperature difference between indoor and outdoor is less than 2 °C. The study suggests to orienting residential high-rise buildings at an oblique angle with the prevalent wind direction than positioning perpendicular to the prevalent wind direction. Furthermore, the framework recommends promoting the wind-driven natural ventilation at top floors of residential high-rise buildings and to facilitate wind and buoyancy-driven natural ventilation at middle and lower floors of the buildings. •Propose a framework to optimize the natural ventilation impact on building energy efficiency.•Computational fluid dynamics is utilized to assess the effect of wind on natural ventilation.•Air change per hour due to wind and/or buoyancy effect is evaluated by multi zone air modelling.•Building thermal load and energy efficiency are evaluated by BIM-supported energy simulation.•Energy demands for various ventilation modes, seasons, flat sizes and positions are studied.