HEATING CONTROL METHOD FOR VEHICLE AND SYSTEM THEREOF

Disclosed are a method for controlling heating of an HVAC system for an electric vehicle and an HVAC system thereof. According to various embodiments, in an operation of the HVAC system including a main heating unit in which a first refrigerant circulates and an auxiliary heating unit in which a second refrigerant circulates, at least one of the first refrigerant and the second refrigerant may comprise at least one of: a natural refrigerant; a hydrofluorocarbon (HFC)-based refrigerant; a hydrofluoroolefin (HFO)-based refrigerant; a hydrochlorofluorocarbon (HCFC)-based refrigerant; a hydrocarbon-based refrigerant that is not a natural refrigerant; and a halon or a perfluorocarbon (PFC)-based refrigerant.