Abstract: The residual moisture inside the air conditioner after cooling creates a high humidity environment, which is the main cause of odor, bacteria, and mold production in the air conditioner. Heat pump drying technology is a necessary means of preventing bacteria and mold inside air conditioners to ensure their healthy use. Based on the innovative design of fresh air conditioning, an internal exhaust system has been developed, which can discharge the water vapor inside the air conditioner to the outside without affecting the user's comfort experience during use. Firstly, it is theoretically analyzed that the moisture content in the air conditioner after drying should be less than or equal to the moisture content before cooling and drying. Then, an orthogonal experiment is designed to determine the main factors affecting the residual water content in the air conditioner. Finally, based on the results of the drying experiment, the calculation formula for the drying rate of the air conditioner unit is inferred. The conclusion is that the air conditioner unit should maintain low humidity (≤ 70%) for a sufficient period of time after drying, with a continuous decreasing trend and a drying rate of ≥ 99%. This serves as the basis for judging the drying of the air conditioner unit and provides technical reference for subsequent research on heat pump air conditioning drying technology.

Key words: Heat pump drying, Fresh air conditioning, Orthogonal experiments, Anti-odor and anti-mildew