Fin of heat exchanger, heat exchanger, and air conditioning apparatus

A fin for a heat exchanger of an air conditioning apparatus, the fin comprising:

• a base material;
• a hydrophilic layer;
• and
• a corrosion-resistant layer provided between the base material and the hydrophilic layer;
• a contact angle of a surface of the hydrophilic layer with water being no more than 50 degrees;
• and
• a water content of the hydrophilic layer per dm2 of the surface of the hydrophilic layer being at least 60 mg/dm2 and no more than 300 mg/dm2,
• the water content being a value obtained by immersing a bottom end of the fin into 1 mm or more of water, recording a mass of the fin when immersed as an initial mass submerging the fin in a predetermined depth of water and leaving the fin submerged for fourteen hours, finding a difference between the initial mass and the mass measured thirty seconds after returning the fin to a position where the initial mass was measured, and dividing the difference by the surface area.