Abstract: Comfortable, healthy and energy efficient are the main design goals of room air conditioners (RACs). Due to the difference between the field test and laboratory test results, this paper carried out the subjective questionnaire survey, tested the indoor thermal environment of two residential buildings in the cooling season, and determined the actual operation performance of the RAC through the all-condition compressor energy balance method. The results show that the indoor thermal environment can basically meet the requirements of comfort for RAC in cooling mode, and the draft may be slightly higher; when the RAC operates, the indoor air quality is poor, and the CO₂ concentration is increased. In terms of the energy performance of the RAC, and the fluctuation of indoor environment is coupled with the performance of the unit. According to the results of comprehensive test and subjective questionnaire survey, the draft and fresh air demand are the direction of improvement of RAC operation in cooling mode.

Key words: Room air conditioner, Cooling, Thermal environment, Field operation performance