Providing healthy air has become an important indicator of air conditioners. In this study

a self-cleaning heat exchanger was designed in a variable refrigerant flow air-conditioning system

and the potential of dedusting and sterilization of the evaporator was investigated experimentally. Firstly

the dust removal and cleaning of the indoor unit were realized by the condensed water generated by the heat exchanger. Secondly

the high temperature generated by the heat exchanger was used to sterilize the indoor unit. A fin-and-tube heat exchanger was utilized in this study

and the amount of condensate water and tube temperature of the evaporator were used as the indicators. The influence of key parameters such as the fan’s rotating speed

compressor frequency

ambient temperature

and operating time on the dedusting and sterilization of the evaporator were analyzed. The experimental results show that the amount of condensate water first increases and then decreases with an increase in fan speed during the dedusting phase

reaching 186 g at a fan speed of 350 r/min when operated under the same condition for 20 min. The condensate water increased with the increase in operating time and the frequency of the compressor. During the sterilization phase

the tube temperature increased with a decrease in the fan speed and reached 58.6 °C at a rotating speed of 200 r/min. Higher outdoor temperatures are beneficial to the tube temperature during the sterilizing stage

but will decrease the amount of condensate water in the dust removal stage.