Refrigeration cycle apparatus with a heating unit for melting frost occurring in a heat exchanger

A refrigeration cycle apparatus including a compressor, a condenser, a first expansion device, and an evaporator having a heat exchanger that includes a plurality of plate-like heat transfer fins arranged in parallel, and a heat transfer tube provided in contact with the plurality of heat transfer fins, the compressor, the condenser, the first expansion device, and the evaporator being connected by refrigerant pipes to form a refrigeration cycle, the refrigeration cycle apparatus comprising:

• an evaporator fan for producing an air current flowing to the evaporator, the evaporator fan being disposed to send the air current in a direction from the evaporator toward the evaporator fan;
• a heating unit disposed on a lower and leeward side of the heat transfer fins of the evaporator;
• and a second expansion device provided in one refrigerant pipe between the first expansion device and the evaporator, wherein at least a part of the heating unit is formed by a part of the one refrigerant pipe between the first expansion device and the second expansion device, the plurality of heat transfer fins of the evaporator are subjected to water slip or water repellent treatment,
• a plurality of fin portions are provided on the part of the one refrigerant pipe forming the heating unit, the plurality of fin portions of the heating unit being disposed along a direction in which the heat transfer fins are arranged in parallel, and the plurality of fin portions provided on the part of the one refrigerant pipe forming the heating unit are inserted between lower and leeward side portions of the heat transfer fins of the evaporator.