Abstract: When the air conditioner of the unit continues to operate in high temperature and high humidity environment, it is easy to trigger the shutdown of high pressure protection frequently, which will affect the comfort of users. In order to solve this problem, through the experimental study of air enthalpy method, the variation law of high pressure with different indoor dry and wet bulb temperatures and outdoor ambient temperature during refrigeration of unit air conditioning system is summarized. On the basis of experimental research, aiming at the pain point of this air-conditioning industry, this paper puts forward some solutions, such as setting the phase current parameters of the air-conditioning compressor, correcting the air-conditioning target frequency through the relative humidity value detected by the indoor unit humidity sensor, and controlling the outdoor unit coil sensor and defrosting sensor separately, so as to provide reference for the subsequent air-conditioning comfort and reliability design.

Key words: Unit air conditioner, High temperature and high humidity, Reliability, Comfort