A vehicle air conditioning apparatus is provided that can prevent temperature variations of the air after the heat exchange in a radiator to reliably control the temperature of the air supplied to the vehicle interior. During the heating operation and the heating and dehumidifying operation, target degree of supercooling SCt when target air-blowing temperature TAO is a predetermined temperature or higher is set to SCt1 that is greater than SCt2 when the target air-blowing temperature TAO is lower than the predetermined temperature. When amount of air Ga supplied from indoor fan 12 is lower than a predetermined value, the target degree of supercooling SCt is corrected, which is set such that the degree of supercooling is lower than target degree of supercooling corrected when the amount of air Ga supplied from the indoor fan 12 is a predetermined value or higher.

Methods and systems for assessing operation of a cooling system of an electric vehicle are described. In one example, a super heating temperature at an inlet of a compressor may be generated solely via a temperature sensor and a pressure sensor. The super heating temperature may be compared against a threshold super heating temperature to judge whether or not an amount of refrigerant in the cooling system is as expected.

Systems and method relate to a fuel efficient automatic temperature control system. The system includes a climate control system configured to heat or cool air. The climate control system includes a condenser and a variable-speed fan. A first sensor provides vent-air information indicative of a condition of the air. An automatic temperature controller receives an indication of a desired temperature, receives the vent-air information, determines whether the variable-speed fan should operate at a maximum fan speed based on at least the desired temperature and the vent-air information and determines whether a dehumidifying operation is requested. If the variable-speed fan is required to operate at the maximum fan speed or a dehumidifying operation is requested, the fan operates at the maximum speed. If the variable-speed fan is not required to operate at the maximum fan speed and a dehumidifying operation is not requested, the fan operates below the maximum fan speed.

A control system for a compressor is provided. The control system includes a controller and first and second control portions. The first control portion is configured to assess an actual temperature of an evaporator and a target temperature of the evaporator and to generate a first compressor speed command signal. The second control portion includes a pressure calibration value and is configured to receive a pressure reading of the climate system, to compare the pressure reading to the pressure calibration value and to generate a second compressor speed command signal. The controller device includes data and is configured to receive the first compressor speed command signal and the second compressor speed command signal and to transmit a control signal to the compressor for causing the compressor to operate at a commanded compressor speed based on the first compressor speed command signal, the second compressor speed command signal, and the data.

A vehicle air conditioning apparatus is provided that can prevent temperature variations of the air after the heat exchange in a radiator to reliably control the temperature of the air supplied to the vehicle interior. During the heating operation and the heating and dehumidifying operation, target degree of supercooling SCt when target air-blowing temperature TAO is a predetermined temperature or higher is set to SCt1 that is greater than SCt2 when the target air-blowing temperature TAO is lower than the predetermined temperature. When amount of air Ga supplied from indoor fan 12 is lower than a predetermined value, the target degree of supercooling SCt is corrected, which is set such that the degree of supercooling is lower than target degree of supercooling corrected when the amount of air Ga supplied from the indoor fan 12 is a predetermined value or higher.

A vehicle air conditioning apparatus is provided that can prevent temperature variations of the air after the heat exchange in a radiator to reliably control the temperature of the air supplied to the vehicle interior. During the heating operation and the heating and dehumidifying operation, target degree of supercooling SCt when target air-blowing temperature TAO is a predetermined temperature or higher is set to SCt1 that is greater than SCt2 when the target air-blowing temperature TAO is lower than the predetermined temperature. When amount of air Ga supplied from indoor fan 12 is lower than a predetermined value, the target degree of supercooling SCt is corrected, which is set such that the degree of supercooling is lower than target degree of supercooling corrected when the amount of air Ga supplied from the indoor fan 12 is a predetermined value or higher.

A vehicle air conditioning apparatus is provided that can prevent temperature variations of the air after the heat exchange in a radiator to reliably control the temperature of the air supplied to the vehicle interior. During the heating operation and the heating and dehumidifying operation, target degree of supercooling SCt when target air-blowing temperature TAO is a predetermined temperature or higher is set to SCt1 that is greater than SCt2 when the target air-blowing temperature TAO is lower than the predetermined temperature. When amount of air Ga supplied from indoor fan 12 is lower than a predetermined value, the target degree of supercooling SCt is corrected, which is set such that the degree of supercooling is lower than target degree of supercooling corrected when the amount of air Ga supplied from the indoor fan 12 is a predetermined value or higher.

The present invention relates to a vehicular heat management system capable of inducing an increase in refrigerant superheat degree without unconditionally turning off a compressor when the refrigerant superheat degree on the discharge side of a chiller is less than or equal to a lower limit value. The vehicular heat management system includes: a compressor; a condensing heat exchanger; an expansion valve; an evaporation heat exchanger; and a control part configured to, when a refrigerant superheat degree on a discharge side of the evaporation heat exchanger is lowered to a predetermined lower limit value or less, control, step by step, at least two devices directly involved in the increase and decrease of the refrigerant superheat degree to increase the refrigerant superheat degree until the refrigerant superheat degree exceeds the lower limit value.

A method for operating a refrigeration system having a heat pump function for motor vehicle, including the following steps: setting a heat pump operation, in which the refrigerant is routed from the refrigerant compressor into the secondary line; setting an expansion valve assigned to the third heat exchanger such that a total mass flow of refrigerant flows through the third heat exchanger; and detecting the temperature of the coolant in the third heat exchanger. The total mass flow of refrigerant is routed through the third heat exchanger when the temperature of the coolant is greater than an upper limiting temperature.

A method of operating a cooling system of a vehicle includes measuring a refrigerant pressure and a refrigerant temperature of a flow of refrigerant in a refrigerant circuit of the cooling system, estimating a relative humidity of a supply airflow across an evaporator of the refrigerant circuit utilizing the measured refrigerant pressure and the measured refrigerant temperature, and changing operation of one or more components of the refrigerant circuit as a result of the estimated relative humidity.