Abstract: APF is the main index to evaluate the energy saving of variable frequency air conditioner. In recent years, the air-conditioning engineer has done a lot of research work on how to improve APF, and the new energy efficiency standard GB 21455-2019 has been formally implemented on July 1, 2020. The team verified the method through simulation calculation and experiment, starting from the compressor frequency, indoor unit fan speed, outdoor unit fan speed and other operating parameters, the seven working conditions involved in the calculation of the new energy efficiency APF are analyzed one by one, and find out the main factors affecting the APF of the variable frequency air conditioner. From this, the irrationality of the mass production model in operation is pointed out, and the corresponding improvement scheme is put forward. The test results show that through the optimization design, the APF is increased by about 2%, and the purpose of improving efficiency is realized. At the same time, it also provides ideas for the continuous improvement of APF of variable frequency air conditioning.

Key words: Inverter air conditioner, APF, Simulation calculation, Experimental verification, Operating parameter