A defrost method for a heat pump system includes running the heat pump system in a heating mode to provide heat to an enclosed space and determining if an outdoor temperature is less than an outdoor threshold temperature. Responsive to a determination that the outdoor temperature is below the outdoor threshold temperature, determining if a calibration state has been previously run. Responsive to a determination that the calibration state has not been previously run, running the heat pump system in the calibration state. Responsive to a determination that the calibration state has been previously run, determining if a temperature difference between a temperature of an evaporator coil of the heat pump system and the outdoor temperature exceeds a temperature threshold value. Responsive to a determination that the temperature difference between the evaporator coil and the outdoor temperature is greater than the temperature threshold value, running the heat pump system in a defrost state.

A heat pump water heater can include a water tank and a refrigerant circuit that can be in fluid communication with an evaporator coil, a condenser coil, and a compressor. The heat pump water heater can include a fan configured to move air across the evaporator coil, a temperature sensor, and a controller. The controller can be configured to receive temperature data from the temperature sensor and, in response to the temperature data indicating a temperature less than a predetermined temperature threshold, output instructions for the compressor to deactivate and the fan to move air across the evaporator coil.

A refrigeration system has: (a) a fluid tight circulation loop including a compressor, a condenser and an evaporator, the evaporator having at least three evaporator zones, each evaporator zone having an inlet port, the circulation loop being further configured to measure the condition of the refrigerant with a refrigerant condition sensor disposed within the evaporator upstream of the evaporator outlet port; and control the flow of refrigerant to the evaporator based upon the measured condition of the refrigerant within the evaporator, and (b) a controller for controlling the flow rate of refrigerant to the evaporator based upon the measured condition of the refrigerant within the evaporator upstream of the evaporator outlet port.

A method of initiating a defrost cycle using a controller of a heat pump system includes measuring a temperature of an evaporator coil and determining whether the temperature of the evaporator coil is less than a freezing temperature. Responsive to a determination that the temperature of the evaporator coil is less than the freezing temperature, determining whether a current dew point temperature of air is greater than the temperature of the evaporator coil. Responsive to a determination that the current dew point temperature of air is greater than the temperature of the evaporator coil, calculating a frost-collection rate. Determining whether the frost-collection rate is greater than a frost-collection-rate threshold, and, responsive to a determination that the frost-collection rate is greater than the frost-collection-rate threshold, initiating a defrost cycle.

A refrigeration cycle device includes a compressor, a heating radiator, a heat medium radiator, a decompressor, an evaporator, and a radiation amount adjuster. The heating radiator is configured to allow a high-pressure refrigerant to release heat to a heat exchange target fluid. The heat medium radiator is configured to allow the high-pressure refrigerant to release heat to a high-temperature side heat medium. The radiation amount adjuster is configured to adjust heat radiation amount radiated from the high-pressure refrigerant to the heat exchange target fluid at the heating radiator. In a heating mode, the radiation amount adjuster is configured to adjust the heat radiation amount at the heating radiator to be larger than a heat radiation amount at the heat medium radiator. In a cooling mode, the radiation amount adjuster is configured to adjust the heat radiation amount at the heating radiator to be lower than that in the heating mode.

A thermal management system for a vehicle includes a heating refrigerant circulation circuit, a heat pump cycle and a heat-discharge refrigerant circulation circuit A heating circulation section of the heating refrigerant circulation circuit, a recovery circulation section of the heat pump cycle, and a heat-discharge circulation section of the heat-discharge refrigerant circulation circuit are integrally configured as a combined heat exchanger that is capable of performing heat transfers at least between the cycle refrigerant and the heating refrigerant and between the heat-discharge refrigerant and the heating refrigerant. Furthermore, the heating refrigerant, the cycle refrigerant and the heat-discharge refrigerant are heat mediums each of which has a phase change during the heat transfer.

A refrigerator includes a controller that is configured to perform operations including driving a refrigerator compartment compressor, determining whether a sensed temperature in the refrigerator compartment satisfies a first temperature, driving, based on the sensed temperature in the refrigerator compartment satisfying the first temperature, a freezer compartment compressor, stopping the refrigerator compartment compressor, maintaining, after stopping the refrigerator compartment compressor, operation of the freezer compartment compressor, restarting the refrigerator compartment compressor, and varying a driving frequency of the refrigerator compartment compressor.

A method of searching for a refrigerant leak location is provided which can easily specify the refrigerant leak location. In the method of searching for the refrigerant leak location in a refrigeration apparatus (100) in which a refrigerant is charged and which includes a refrigeration circuit (10) performing a refrigeration cycle, the refrigeration circuit (10) is prepared in a state that the refrigerant containing an odor component is charged therein, and the refrigerant leak location is specified by letting a dog capable of detecting the odor component to run along the refrigeration circuit (10).

A heat exchanger, in particular a chiller, includes a heat exchanger block with a first fluid duct for a refrigerant and a second fluid duct for a coolant, an inlet and an outlet for the refrigerant, which are formed at a connecting flange and which are fluidically connected to the first fluid duct, a sensor for detecting a measured variable of the refrigerant, and an electronic expansion valve arranged in the inlet including an integrated regulating unit, wherein the expansion valve regulates a flow rate of the refrigerant in the inlet as a function of the detected measured variable. The sensor and the regulating unit are connected via a cable to transfer data. A port is formed at the expansion valve. The cable is further secured releasably or non-releasably in the respective port at the expansion valve. In addition, a method for controlling or regulating the heat exchanger is provided.

A set temperature calculating apparatus, a low temperature treatment system, a set temperature calculating method, and a set temperature calculating program are provided for realizing a low temperature treatment. The set temperature calculating apparatus includes: a first obtaining unit configured to obtain data correlating with a heat load in a container storage; a second obtaining unit configured to obtain a set temperature when performing temperature control in the container storage; and a learning unit configured to learn a cargo core temperature in the container storage according to a data set including a combination of the data correlating with the heat load and the set temperature.