40 days’ tracking test on the performance of a heat pump type of room air conditioner charged with a new kind of additive called polarized refrigerant oil additive (PROA) was carried out under the standard working condition.The result of the experiment shows that the suction and discharge temperatures of the compressor decline obviously,but the fluctuations of them are just about 1.5 ℃during the long running period when the PROA is used.Furthermore,the temperatures and pressures of suction and discharge have only little change,and there is also no negative effect on key components such as compressor.It illustrates that the PROA constantly plays an active role in the air conditioning system.