A photovoltaic (PV) integrated energy system is an ideal alternative to meet the heavy power demand of air conditioners in summer in hot climate areas. This paper presents the practical operation of a grid-connected, photovoltaic-powered, central air conditioner for an office building in South China. Typical operation characteristics have been analyzed regarding three indices such as solar fraction (SF), net solar fraction (NSF) and surplus energy ratio (SER). Different weather patterns such as sunny, cloudy and overcast based on the percentage of cloud coverage have been considered in this study. It is found that the performance of the system was significantly influenced by the meteorological conditions and that the value of SF is in different ranges for the three weather patterns. Additionally, the NSF and SER show meaningful trends for the three weather patterns. In addition, the SF is high in April, September and October due to the low cooling load. The yearly average values of SF, NSF and SER are 51.62%, 104.5% and 52.72%, respectively. The study methods proposed in this paper might be useful to predict and design PV integrated air-conditioning systems in different areas. This paper is presented and recommended by 5th International Conference on Nuclear and Renewable Energy Resources.