Reasonable mechanical ventilation strategy and system design can effectively save building energy usage for space cooling in summer. In this paper, the climatic cooling potential of major cities in China is evaluated based on the CCP index values, and a guide map for accessing night cooling potential is provided. Furthermore, for ventilation strategy optimization in city buildings, the ideal air change rate (ACH) is obtained by using inverse problem approach. The preliminary results indicate that the ideal ventilation strategy is favorable for free cooling energy exploitation in the night, to save cooling energy consumption in summer. It also shows that both CCP value and energy saving ratio of ventilation optimization decreases from north to south in China. This study is significant in guiding and optimizing building ventilation systems in engineering applications.
Keywords building energy efficiency, night ventilation, inverse problem, space cooling