What is hot air defrosting?

Hot air defrosting is different from refrigeration reverse cycle defrosting.

Hot gas defrosting is a heating defrosting method in which the heat pump controls the flow through an electronic expansion valve. The air conditioner still maintains the heating mode when defrosting, and the electronic expansion valve is fully opened, so that the refrigerant enters the condenser for heat exchange and defrosting and remains at a high temperature, and the defrosted refrigerant returns to the compressor accumulator. Because the high-temperature refrigerant must first flow through the evaporator of the indoor unit when defrosting, it can ensure that the evaporator always keeps high temperature. After defrosting, the electronic expansion valve is reset and the normal heating operation mode is restored.

Note: During defrosting, indoor and outdoor fans are turned off to minimize the loss of refrigerant enthalpy.