Abstract: A method for operating a heat pump of a motor vehicle that includes a compressor, an expander, an ambient heat exchanger and a heating heat exchanger. In the method, a defrost mode for defrosting the ambient heat exchanger is initiated. In the defrost mode, a refrigerant is compressed to a high pressure by the compressor to transfer thermal energy to the ambient heat exchanger, the refrigerant is expanded to a low pressure by the expander, and the refrigerant absorbs thermal energy in the heating heat exchanger. Further, a defrosting process of the ambient heat exchanger triggered by the defrost mode is monitored. The monitoring of the defrosting process includes monitoring the pressure difference between the high pressure and the low pressure and/or monitoring the pressure gradient of the pressure difference between the high pressure and the low pressure and/or monitoring the high pressure.

Abstract: A method for operating a heat pump for a motor vehicle is proposed, wherein the heat pump comprises a refrigerant circuit with a refrigerant, an ambient heat exchanger, a compressor, a heating heat exchanger, and a throttle. The method comprises determining an expected start time of a charging process of a motor vehicle battery and determining a maximum dew point undershoot and/or a maximum frost mass. The method further comprises operating the heat pump such that the maximum dew point undershoot and/or the maximum frost mass are reached within a predefined time period before the expected start time.

Abstract: In order to provide a method for initiating a defrosting process of a heat exchanger of a heat pump of a motor vehicle, which method is insensitive to external parameters influencing the air flow through the evaporator, and with which method unnecessary defrosting processes can be avoided, wherein a fan is assigned to the heat exchanger, wherein a power consumption and/or a speed of the fan is monitored, a defrosting process is initiated when the power consumption and/or the speed exceeds and/or falls below a threshold value, and the threshold value is determined as a function of a parameter, wherein the parameter is an indicator of a current relative air speed of the ambient air in relation to the motor vehicle.

Abstract: A method for operating a heat pump of a motor vehicle comprising a compressor, an expander, an ambient heat exchanger and a heating heat exchanger. The method comprises initiating a defrost mode for defrosting the ambient heat exchanger, wherein the defrost mode comprises the steps of: Compressing a refrigerant to a high pressure by means of the compressor, transferring thermal energy to the ambient heat exchanger, expanding the refrigerant to a low pressure by means of the expander, and absorbing thermal energy. The method is characterized by monitoring a defrosting process of the ambient heat exchanger triggered by the defrost mode, wherein the monitoring of the defrosting process comprises monitoring a pressure difference between the high pressure and the low pressure and/or monitoring a pressure gradient of the pressure difference between the high pressure and the low pressure and/or monitoring the high pressure.