Fin-and-tube heat exchangers are widely used in indoor units of air conditioners. When the indoor unit heat exchanger is served as evaporator

dehumidification may occur on the fin surface and dust particles easily adhere to the wet fin surface

leading to an increase of air flow resistance. In this paper

the particle deposition characteristics on fin-and-tube heat exchangers under dehumidifying conditions and the influence of deposited wet particles on the air-side pressure drop are experimentally studied. The fin types of test samples cover plate fin

wavy fin and louver fin. The range of fin pitch is 1.5-2.2 mm. The results show that the particle deposition amount is determined by the degree of dehumidification

and the particle deposition amount on windward side of fins as well as the air-side pressure drop increase as the amount of condensate droplets and liquid bridges. Louver fin or small fin pitch is more inclined to wet particle deposition as well as the increase of pressure drop and simplifying fin structure or increasing fin pitch is beneficial to wet particle prevention. The air-side pressure drop firstly increased then tended to be stable with the increase of wet particle deposition amount.