Design-based natural ventilation cooling potential evaluation for buildings in China

Abstract

Natural ventilation is generally accepted as an innovative green building design strategy and an effective sustainable option. The purpose of the study is to identify where and when the use of natural ventilation cooling can be considered in the predesign programming stage and conceptual building design stage in China. Quantitative evaluations are valued during these stages because the building form determines, in no small measure, the performance of natural ventilation. An ISO-standardized energy performance calculator incorporating a dedicated controllable ventilation model is then proposed as a “pre-evaluation” tool before the design performance modelling stage. Six scenarios in 100 cities under five standards are analysed, including hybrid ventilation with a night-purge ventilation strategy and pure natural ventilation with a window opening strategy. The potential is estimated based on weather, relative humidity, target air change rate, fresh air supply mode, building configuration, and set point schedule which considering night and weekend indirect cooling. For an annual hybrid ventilation conditioned building, Kunming is proposed as a top priority for building site selection among 100 cities. During particular seasons, different climate zones show stark cooling effectiveness, and 60–100% of the cooling demands can be satisfied. For a purely natural-ventilated building, Qinghai-Tibet Plateau, Yunnan-Kweichow Plateau and the east of Inner Mongolian Plateau are recommended. Three of 35 observed cities can be satisfied totally by natural ventilation cooling. The necessary generic provisions in terms of control logic are derived and can be used to guide specific design choices. The findings also provide guidelines for adapting Chinese building codes to raise awareness of natural ventilation options.