Effect of surface treatments on the frosting/defrosting behavior of a fin-tube heat exchanger

The effects of the heat exchanger surface treatment on the frosting/defrosting behavior in a fin-tube heat exchanger are investigated experimentally. It is found that the hydrophilic surface mainly influences the frosting behavior, while the hydrophobic surface has some influence on the defrosting behavior. In view of the frosting, a surface-treated heat exchanger with either hydrophilic or hydrophobic characteristic shows little improvement in the thermal performance rather than the bare aluminum heat exchanger. The results reveal that the heat exchanger with a hydrophobic surface treatment is more effective in view of the defrosting efficiency and time. The amount of residual water on the surface-treated heat exchangers is shown to be smaller than that of the bare heat exchanger. Therefore further improvements on the performance of re-operations are expected.