Through the method of experiment and simulation, some optimized designs have been carried out to improve the performance in intermediate working conditions during the process of performance matching for APF of R32 variable speed room air-conditioner. In this paper the main reason for the poor performance in intermediate conditions of R32 air conditioning system is clarified by the analysis of the heat exchange between the refrigerant side and the air side, and some optimized designs of the indoor unit heat exchanger\u27s pipeline layout and pipe diameter have been carried out. The optimization results show the performance of the intermediate condition has been improved by about 4%, and the performance of APF of the R32 room air conditioning system has been increased by 3.8% compared with the original unit
