To avoid deterioration in the performance of air conditioner heat exchangers after prolonged operation

the dust deposited on the fin surfaces should be removed in a timely manner. In this paper

the frosting–defrosting process of heat exchangers was used to realize the dust removal

and the effect of fin surface coatings on dust removal process was experimentally evaluated. Four test samples

including an uncoated aluminum plate

an uncoated copper plate

a hydrophilic copper plate

and a hydrophobic copper plate

were evaluated in the experiment. The hydrophilic copper plate and hydrophobic copper plate were prepared via a self-assembly method. A visual experimental apparatus was fabricated to observe the dust removal on various samples via the frosting–defrosting process. The dust removal rate and remnant dust weight were obtained. The frosting condition involves a surface temperature of -10 °C

frosting time of 1 h

air temperature of 27 °C

and relative air humidity of 50%. Furthermore

the defrosting condition corresponds to a surface temperature of 5 °C. The dust removal on the hydrophobic surface exhibits the best performance when compared to other samples. The remnant dust weight on the hydrophobic surface is only 1.9% of that on the aluminum surface

2.0% of that on the copper surface

and 5.9% of that on the hydrophilic surface.