Abstract: A cooling and battery cooling mode is performed to release the heat from the refrigerant in a heat releasing unit and an outdoor heat exchanger and to absorb the heat into the refrigerant in a heat absorbing unit and a refrigerant-heat medium heat exchanger, and a heating and battery cooling mode is performed to release the heat from the refrigerant in the heat releasing unit and to absorb the heat into the refrigerant in the outdoor heat exchanger and the in-vehicle device heat exchanger. In a case where the cooling and battery cooling mode is performed, when a temperature of the heat absorbing unit is lower than a target value of the temperature of the heat absorbing unit even though the flowing of the refrigerant into the heat absorbing unit is blocked, the operation mode is moved to the heating and battery cooling mode.

Abstract: Method for testing the functional stability of a controller of a refrigerating machine where the controller performs control cycles. The testing method comprises a step (100) of recording a set of current values of input variables, status variables and output variables of the controller, and a subsequent execution step (200), in which the values of the status variables and input variables recorded in the recording step are forced in the controller as inputs and values of the output variables are recorded in order to compare them with the values of the output variables recorded in the recording step (100).

Abstract: A method of remotely managing a transport climate control system (TCCS) includes a remote management device receiving performance data from the TCCS. The performance data based on one or more detected operating parameters of the climate control circuit. The method also including the remote management device providing the performance data to one or more user devices. A remote management system includes a remote management device configured to receive performance data for a climate control circuit from a climate controller of a TCCS and to provide the performance data to one or more user devices. A TCCS includes a controller configured to: generate performance data based on the one or more detected operating parameters of a climate control circuit, and transmit the performance data to a remote monitoring device. The climate controller also configured to receive an operating instruction from the remote monitoring device.

Abstract: An apparatus and a method for detecting refrigerant leakage in an air source heat pump system. The method for detecting refrigerant leakage in an air source heat pump system includes the following steps in a cooling mode: S110: obtaining a running parameter of an air source heat pump system, wherein the running parameter at least includes a compressor rotational speed; S120: comparing the running parameter with a preset running parameter range; S130: updating a cumulative score when the running parameter falls within the preset running parameter range; and S140: when the cumulative score exceeds a predetermined cumulative score, determining that refrigerant leakage occurs, and when the cumulative score does not exceed the predetermined cumulative score, return to step S110.

Abstract: A heat pump system includes a compression device 12, a heat rejecting heat exchanger 14, an expansion device 18 and a heat absorbing heat exchanger 16; wherein the expansion device 18 provides a controllable degree of expansion. The heat pump system is operated in accordance with a method including determining a temperature indicative of frosting conditions on an exterior surface of the heat absorbing heat exchanger 16; operating the heat pump system in a first mode if the temperature indicative of frosting conditions is above a threshold value, and operating the heat pump system in a second mode if the temperature indicative of frosting conditions is within a range of temperatures that is below the threshold value.

Abstract: Disclosed herein are air conditioning systems including a refrigerant line configured to transport a refrigerant; a compressor in fluid communication with the suction line; and a controller in communication with a sensor configured to measure a characteristic of the refrigerant line. The compressor can be configured to move the refrigerant through the refrigerant line, and the refrigerant can have a first temperature at the outlet of the compressor. The controller can be configured to receive sensor data from the sensor indicating a current value associated with the characteristic of the refrigerant line; determine, based at least partially on the sensor data, that the characteristic of the refrigerant line is above a predetermined threshold; and output instructions for the compressor to perform one or more corrective actions.

Abstract: An air-conditioning apparatus includes an outdoor unit and an indoor unit that include devices and a pipe constituting a refrigerant circuit and a remote control connected to the indoor unit. Each of the outdoor unit and the indoor unit includes a sensor configured to detect temperature states of the devices and the pipe. The outdoor unit or the indoor unit includes a memory configured to hold sensor information indicating a result of the detection by the sensor and control information indicating control states of the devices. The remote control includes a microcomputer configured to receive information indicating states of sections based on the sensor information and the control information, output an estimated cause of trouble as output values, and compute a value corresponding to a possibility of being cause of trouble by using a neural network, and a display unit configured to display a result.

Abstract: The present invention relates to an air conditioner. The air conditioner according to the present embodiment has a refrigeration capacity of 7 kW to 11 kW, inclusive, and uses, as a refrigerant, a mixed refrigerant containing 50% or more of R32, and since a refrigerant pipe therein is made of a ductile stainless steel material having 1% or less of a delta-ferrite matrix structure with respect to the grain size area thereof, and includes a suction pipe guiding the suction of the refrigerant into a compressor and having an outer diameter of 15.88 mm, the refrigerant pipe can maintain strength and hardness as good as or better than those of a copper pipe, while also maintaining good processability.

Abstract: The present invention relates to an air conditioner. A first invention according to the present embodiment is an air conditioner which has a refrigeration capacity of 16 kW to 28 kW, inclusive, and uses a mixed refrigerant R134a as a refrigerant, and in which a refrigerant pipe includes a ductile stainless steel pipe having 1% or less of a delta-ferrite matrix structure with respect to the grain size area thereof.

Abstract: An air conditioner includes: an indoor unit including a blowing unit to discharge air; an outdoor unit supplying compressed refrigerant to the indoor unit, to exchange heat with the air before discharge. The air conditioner also includes at least one computer memory operably connectable to at least one processor and storing instructions that, when executed, perform operations that include: generating at least one parameter in a first operation mode, which is operated only within a preset time range; controlling, based on an operation mode information, at least one of (i) the blowing unit to change a wind direction and an air volume, or (ii) the outdoor unit; and switching to a second operation mode after a time period of operation in the first operation mode. The operation mode information includes at least one result factor obtained from at least one machine-learning network.

Abstract: An air conditioning system. A first evaporator and a second evaporator are connected in parallel. A first electronic expansion valve is serially connected to the first evaporator, and a second electronic expansion valve is serially connected to the second evaporator, so that the opening degrees of the first electronic expansion valve and the second electronic expansion valve can be separately adjusted, the first electronic expansion valve and the second electronic expansion valve can perform position correction according to valve opening position information of the first electronic expansion valve and the second electronic expansion valve stored by the air conditioning system, and separately adjust target positions to calibrated target positions. Also disclosed are a control system and a control method for the air conditioning system.

Abstract: A refrigerant cycle of the present invention includes including an outdoor unit, a plurality of indoor units, and a controller for controlling the refrigeration cycle using at least one EEV. The controller comprises a velocity PID component executing a velocity PID control using pulse number for driving an EEV, three-state controller determining a driving state of the EEV and generating pulse commands designating the driving state, and a state machine driving the EEV depending on the pulse commands generated by the three-state controller.

Abstract: A driving device includes a connection switching unit to switch a connection state of coils between a first connection state and a second connection state in which a line voltage is lower than in the first connection state, a controller to control a motor and the connection switching unit, and a rotation speed detector to detect a rotation speed of the motor. When the connection state of the coils is the first connection state and the rotation speed detected by the rotation speed detector becomes higher than or equal to a first rotation speed, the controller causes the motor to rotate at a second rotation speed higher than the first rotation speed, and then causes the connection switching unit to switch the connection state of the coils from the first connection state to the second connection state.

Abstract: An evaporator controller for a plural-coil evaporator of a refrigeration system, the evaporator controller comprising a mode determiner for selecting a mode of operation of the evaporator from a plurality of modes of operation, wherein one mode uses a first coil of the plurality of coils of the evaporator, another mode uses a second coil of the plurality of coils of the evaporator and at least one mode uses more than one of the plurality of coils, based on selection data and a refrigeration requirement, and a selection data updater for updating the selection data based on the selected mode of operation and a process variable of the refrigeration system.

Abstract: An HVAC&R monitor detects short-term and long-term system efficiency degradations by modeling either compressor input power or current. The model is continuously updated with new or recent temperature and power parameter measurements reflecting the most up-to-date operating condition of the system. Short-term system degradations are detected instantaneously by comparing compressor power or current as predicted by the model against measured power or current usage. Long-term system degradations are detected over time by monitoring the sensitivity of the compressor power or current usage to evaporator and/or condenser fluid temperatures. An appropriate warning and/or signal may be issued if system efficiency degradation is detected.

Abstract: A method of cooling a motor coupled to a compressor of a chiller includes adjusting a position of a motor cooling valve located fluidly between the motor and a refrigerant source, using a motor temperature control system coupled to the motor cooling valve to regulate an amount of refrigerant introduced into the motor from the condenser according to a temperature control scheme performed as a function of a monitored temperature in the motor, a first temperature threshold, and a second temperature threshold lower than the first temperature threshold. The temperature control scheme includes a motor cooling control process that adjusts the position of the motor cooling valve based on a stator winding temperature set point relating to stator windings of the motor. A proportionally limited close command override associated with a first temperature range above the second temperature threshold proportionally limits a close command provided to the motor cooling valve.

Abstract: A method and system for improving energy efficiency of a refrigeration system include system components such as a condenser, one or more expansion valves, an evaporator, one or more compressors, and a system controller electrically coupled to the one or more of the system components, according to one embodiment. The system controller is configured to selectively actuate, directly or indirectly, the one or more expansion valves, the condenser, and/or the one or more compressors, at least partially based on temperatures and/or pressures of the system fluid at various points of the system, to control a temperature of a refrigerated area.

Abstract: A CO2 refrigeration system includes a CO2 refrigeration subsystem that provides cooling for a refrigeration load using carbon dioxide (CO2) as a refrigerant. The CO2 refrigeration system further includes a direct CO2 heat exchange subsystem that uses the CO2 refrigerant from the CO2 refrigeration subsystem to provide heating or cooling for a building zone. The direct CO2 heat exchange subsystem includes a heat exchanger that exchanges heat directly between the CO2 refrigerant and an airflow provided to the building zone.

Abstract: A refrigeration cycle apparatus controller includes an expansion-valve controller configured to output an opening-degree command for an expansion valve based on a deviation between a discharge temperature of refrigerant discharged from a compressor and a set discharge temperature, and at least two control parameters including a proportionality coefficient and an integral coefficient, a flow-rate-correction-coefficient calculator configured to calculate a flow-rate correction coefficient from a refrigerant flow rate of refrigerant circulating through a refrigerant circuit and a preset flow-rate reference value, and a coefficient corrector configured to calculate the proportionality coefficient by correcting a preset proportionality-coefficient reference value based on the flow-rate correction coefficient, and calculate the integral coefficient by correcting a preset integral-coefficient reference value based on the flow-rate correction coefficient.

Abstract: Provided are a gas-replenishing and enthalpy-increasing control method, device and apparatus for a two-stage compressor. The method includes: when a gas-replenishing electronic expansion valve needs to be opened, gradually increasing, by a controller, an opening degree of the gas-replenishing electronic expansion valve in a time sequence; after the gas-replenishing electronic expansion valve is opened, acquiring a detected gas-replenishing superheat degree of a two-stage compressor; and adjusting, based on the gas-replenishing superheat degree of the two-stage compressor, the opening degree of the gas-replenishing electronic expansion valve, wherein the gas-replenishing electronic expansion valve is disposed between a medium-pressure liquid storage tank and the two-stage compressor, and when the opening degree of the gas-replenishing electronic expansion valve is not zero, a gaseous refrigerant in the medium-pressure liquid storage tank replenishes gas and increases enthalpy for the two-stage compressor.

Abstract: In an air conditioning apparatus, an expansion valve is determined to be in a fully closed state when a refrigerant temperature in an outlet of an indoor heat exchanger and a refrigerant temperature in an inlet or an intermediate part of the indoor heat exchanger satisfy a closed-valve condition. The temperature in the outlet is detected by a gas-side temperature sensor. The temperature in the inlet or the intermediate part is detected by a liquid-side temperature sensor. The closed-valve condition is in relation to a refrigerant evaporation temperature obtained by converting a refrigerant pressure in an intake side of a compressor to a refrigerant saturation temperature, and in relation to an air temperature of an air-conditioned space cooled by the indoor heat exchanger. The pressure in the intake side is detected by an intake pressure sensor. The air temperature is detected by an indoor temperature sensor.

Abstract: An air conditioner has a control-data storage unit to store therein control data, a buffer unit to store therein update data of the control data, a rewriting unit, a data reception unit, and a reception processing unit. The rewriting unit executes a rewriting process of rewriting the control data stored in the control-data storage unit with the update data stored in the buffer unit. The data reception unit receives, through a wireless communication, the update data that is transmitted multiple times from a transmitter. The reception processing unit determines whether the rewriting process is in progress at a time when the update data is received, discards the received update data if the rewriting process is in progress, and stores the received update data in the buffer unit if the rewriting process is not in progress.

Abstract: The present invention provides a control system for managing lubricant levels in tandem compressor assemblies of a heating, ventilation, and air conditioning (HVAC) system. In transitioning from a partial load that operates a first compressor but not a second compressor of a tandem assembly to a full load that operates both the first and the second compressor, a controller of the HVAC system turns OFF both compressors of the tandem compressor assembly to allow time for lubricant levels to equalize between the first and the second compressor.

Abstract: Systems and methods are disclosed that include providing a heating, ventilation, and/or air conditioning (HVAC) system with a temperature sensor validation system that measures the ambient outdoor temperature using a first temperature sensor and the refrigeration coil temperature using a second temperature sensor at a plurality of time intervals following a refrigeration coil defrost procedure. A system controller may implement an algorithm to determine if the first temperature sensor and the second temperature sensor are reliable by comparing the temperature readings from the first temperature sensor and the second temperature sensor taken at the plurality of time intervals following the defrost procedure. The system controller may also implement so-called limp along modes if any temperature sensor is determined unreliable.

Abstract: A system includes a heat pump configured to match a working heat transfer fluid temperature to a fluid temperature set-point, a fluid pump in fluid communication with the heat pump through the heat transfer fluid and configured to match the heat transfer fluid pressure/flow to a fluid pressure/flow set-point, at least one heat exchanger in fluid communication with the fluid pump, and a supervisory controller in signal communication with the at least one heat exchanger, the fluid pump, and the heat pump. The at least one heat exchanger includes a proportional valve and a return air temperature gauge configured to monitor return air temperature associated therewith. The supervisory controller is configured to vary the fluid temperature set-point and vary the fluid pressure/flow set-point based upon a position of the proportional valve and the return air temperature.

Abstract: Systems and methods of the invention relate to diagnosing a compressor. A method may include monitoring a pressure of compressed air within a reservoir of a compressor, actuating an unloader valve of the compressor, and detecting a leak condition of the compressor through recognition of a change in the monitored pressure of the compressed air within the reservoir during a time period in which the unloader valve is actuated. A system is also disclosed including an engine, a compressor operatively connected to the engine, and a controller that is operable to determine a condition of the compressor.

Abstract: The refrigerant discharged from a compressor is distributed based on the priorities set by the user in advance and the remaining refrigerant is further distributed based on the priorities. Thus, setting the priorities for indoor units according, for example, to the usage of work spaces and the like in an office building, the user can operate a heat pump system efficiently in accordance with the intended use. Furthermore, the remaining capacity of the outdoor unit is distribute to the remaining indoor units according to their priorities so that the indoor units are operated efficiently within the range of the cooling capacity of the outdoor unit.

Abstract: A system for controlling the flow of a fluid from a source to a load includes a source. An on/off type of control valve communicates with the source. A micro-electric mechanical system communicates with the on/off type of control valve. A consuming device communicates with the micro-electric mechanical system. An electronic controller that communicates with the consuming device and the source. The electronic controller measures a change in a parameter of the micro-electric mechanical system that results from the flow of fluid through the micro-electric mechanical system to sense a flow of fluid through a micro-electric mechanical system.

Abstract: An appliance includes an appliance housing, an interface adapted to receive power information, a plurality of sensors for sensing environmental conditions, a plurality of controls for controlling operations of the appliance, and an intelligent control. The intelligent control is disposed within the appliance housing and operatively connected to the interface and the plurality of sensors and adapted to dynamically select control values associated with the plurality of controls based on at least one of the power information, the environmental conditions, or a combination thereof to increase energy efficiency of the appliance.

Abstract: A refrigeration vapor compression system including a compressor, an electronic expansion valve with closed loop feedback into a controller, sensors to measure and monitor the system superheat and sub-cooling, and condenser fans controlling the flow of air through the condensing coils, the refrigeration system is operated in at least one of two functional modes to either give priority control to the level of superheat in the system or maintain a minimum level of sub-cooling in the system.

Abstract: A fan includes a hub, several fan blades, and a motor that is operable to drive the hub. A motor controller is in communication with the motor, and is configured to select the rate of rotation at which the motor drives the hub. The fan is installed in a place having a floor and a ceiling. An upper temperature sensor is positioned near the ceiling. A lower temperature sensor is positioned near the floor. The temperature sensors communicate with the motor controller, which includes a processor configured to compare substantially contemporaneous temperature readings from the upper and lower temperature sensors. The motor controller is thus configured to automatically control the fan motor to minimize the differences between substantially contemporaneous temperature readings from the upper and lower temperature sensors. The fan system may thus substantially destratify air in an environment, to provide a substantially uniform temperature distribution within the environment.

Abstract: A refrigerant expansion valve for a refrigerant system includes a main body, a motor and first and second members. The main body has a refrigerant flow passage that extends therethrough. The first and second members are connected together and are configured with threads that have a different pitch to allow for relative movement between both members and the main body. The motor is positioned adjacent the main body and is coupled to the first member. The motor actuates the first member in response to control signals to move the second member within the main body to modulate the flow of refrigerant through the refrigerant flow passage.

Abstract: Thermal subsystems of manufactured information handling systems are tested for compliance with desired parameters by running a thermal diagnostics module in firmware during one or more manufacturing activities performed on the information handling system. The thermal diagnostics module monitors and stores one or more thermal parameters detected at the information handling system, such as the maximum temperature zone detected during a manufacturing activity. The stored thermal parameter is read after the manufacturing activity and compared with an expected value to determine the status of the thermal subsystem. For instance, an information handling system maximum operating temperature is detected by firmware running on an embedded controller during imaging of a hard disk drive and fails thermal testing if the detected maximum operating temperature exceeds a predetermined value, such as a value that would not be reached if the thermal subsystem functioning properly.

Abstract: A refrigerant cycle is provided with a control for an expansion device to achieve a desired compressor discharge pressure. The system operates transcritically, such that greater freedom over compressor discharge pressure is provided. The system's efficiency is optimized by selecting an optimum discharge pressure. The optimum discharge pressure is selected based upon sensed environmental conditions, and the expansion device is adjusted to achieve the desired compressor discharge pressure. A feedback loop may be provided to sense the actual compressor discharge pressure and adjust the actual compressor discharge pressure by further refining the expansion device. The system is disclosed providing heated water based upon a demand for a particular hot water temperature.

Abstract: Thermal subsystems of manufactured information handling systems are tested for compliance with desired parameters by running a thermal diagnostics module in firmware during one or more manufacturing activities performed on the information handling system. The thermal diagnostics module monitors and stores one or more thermal parameters detected at the information handling system, such as the maximum temperature zone detected during a manufacturing activity. The stored thermal parameter is read after the manufacturing activity and compared with an expected value to determine the status of the thermal subsystem. For instance, an information handling system maximum operating temperature is detected by firmware running on an embedded controller during imaging of a hard disk drive and fails thermal testing if the detected maximum operating temperature exceeds a predetermined value, such as a value that would not be reached if the thermal subsystem functioning properly.

Abstract: In a vehicle air conditioner, at least one of an inner surface temperature of a passenger compartment and a surface temperature of a passenger in each detection area is the passenger compartment is detected by an infrared rays sensor, and a control unit determines a solar radiation condition such as a solar radiation amount and a solar radiation direction in the passenger compartment based on the surface temperature detected by the infrared rays sensor. The control unit controls operation of an operation member such as an air mixing door, based on the determined solar radiation condition. Thus, uncomfortable feeling given to the passenger can be reduced regardless of the solar radiation condition.

Abstract: A method and apparatus for refrigeration system control includes a control system operable to meet cooling demand and control suction pressure for a plurality of refrigeration circuits each including a variable valve and an expansion valve. The controller controls the variable valve independently of the expansion valves to meet cooling demand by determining a change in a measured parameter and controlling at least one of the variable valves based upon the change to an approximately fully open position.

Abstract: An apparatus for controlling the temperature of an electronic device under test includes a thermal head having a temperature controlled surface for making thermal contact with the electronic device. The thermal head defines a flow channel for passage of a refrigerant fluid so as to cause transfer of thermal energy between the electronic device and the thermal head. A refrigeration system is connected in fluid communication with the flow channel of the thermal head to supply refrigerant fluid thereto. The refrigeration system includes a metering valve operative to regulate introduction of the refrigerant fluid into the thermal head. A controller is operative to control the metering valve for maintaining a predetermined temperature at the temperature controlled surface.

Abstract: An air conditioning apparatus preferentially ventilates a space close to a seat and/or a steering wheel on which a passenger directly makes a contact in a passenger compartment while a vehicle is parked. The uncomfortable feeling of a passenger that might occur when he/she is getting into the parked vehicle can be reduced using a small capacity in the air conditioning as compared to the air conditioning apparatus ventilating the whole space in the vehicle.

Abstract: An exemplary embodiment is a cooling system for cooling multiple logic modules. The cooling system includes a condenser, a first electrically controlled expansion valve coupled to the condenser and a first evaporator coupled to the first electrically controlled expansion valve. A second electrically controlled expansion valve is coupled to the condenser and a second evaporator coupled to the second electrically controlled expansion valve. A controller provides control signals to the first electrically controlled expansion valve and the second electrically controlled expansion valve to control operation of the first electrically controlled expansion valve and the second electrically controlled expansion valve. A compressor is coupled to the first evaporator, the second evaporator and the condenser.

Abstract: A system for monitoring a remote refrigeration system includes a plurality of sensors that monitor parameters of components of the refrigeration system and a communication network that transfers signals generated by each of the plurality of sensors. A management center receives the signals from the communication network and processes the signals to determine an operating condition of at least one of the components. The management center generates an alarm based on the operating condition.

Abstract: A system and method for cooling a room configured to house a plurality of computer systems. A heat exchanger unit is configured to receive air from the room and to deliver air to the room. The heat exchanger unit is supplied with cooling fluid operable to cool the received air in the heat exchanger unit. At least one of the temperature of the cooling fluid supplied to the heat exchanger unit and the air delivery to the room may be controlled in response to temperatures sensed at one or more locations in the room.

Abstract: A system and method for cooling a room configured to house a plurality of computer systems. A heat exchanger unit is configured to receive air from the room and to deliver air to the room. The heat exchanger unit is supplied with cooling fluid operable to cool the received air in the heat exchanger unit. At least one of the temperature of the cooling fluid supplied to the heat exchanger unit and the air delivery to the room may be controlled in response to temperatures sensed at one or more locations in the room.

Abstract: An air conditioning apparatus preferentially ventilates a space close to a seat and/or a steering wheel on which a passenger directly makes a contact in a passenger compartment while a vehicle is parked. The uncomfortable feeling of a passenger that might occur when he/she is getting into the parked vehicle can be reduced using a small capacity in the air conditioning as compared to the air conditioning apparatus ventilating the whole space in the vehicle.

Abstract: In a vehicle air conditioner, at least one of an inner surface temperature of a passenger compartment and a surface temperature of a passenger in each detection area is the passenger compartment is detected by an infrared rays sensor, and a control unit determines a solar radiation condition such as a solar radiation amount and a solar radiation direction in the passenger compartment based on the surface temperature detected by the infrared rays sensor. The control unit controls operation of an operation member such as an air mixing door, based on the determined solar radiation condition. Thus, uncomfortable feeling given to the passenger can be reduced regardless of the solar radiation condition.

Abstract: An apparatus for controlling the temperature of an electronic device under test includes a thermal head having a temperature controlled surface for making thermal contact with the electronic device. The thermal head defines a flow channel for passage of a refrigerant fluid so as to cause transfer of thermal energy between the electronic device and the thermal head. A refrigeration system is connected in fluid communication with the flow channel of the thermal head to supply refrigerant fluid thereto. The refrigeration system includes a metering valve operative to regulate introduction of the refrigerant fluid into the thermal head. A controller is operative to control the metering valve for maintaining a predetermined temperature at the temperature controlled surface.

Abstract: The performance of mobile air conditioning systems is improved with the use of a pressure sensing valve to control refrigerant flow in the system. The pressure sensing valve is connected between the condenser and the evaporator. The control valve senses the refrigerant pressure adjacent the evaporator, ie. the input, or output, or the combination of both, to control the refrigerant flow through the evaporator in a manner to improve the performance of the system. The reference pressure for the valve can be the atmosphere or a fixed or variable source. Various other operating variables can be sensed to control the variable source in a manner to interact with the sensed pressure to provide added control of system performance.

Abstract: An air conditioner having a permanent magnet electric motor with a high output power characteristic in a cooling and heating range and a high output characteristic even in defrosting operation in a high-speed range.

Abstract: An improved refrigeration system utilizing a subcooler/economizer is provided. The refrigeration system comprises a compressor, a condenser, a refrigeration case, and an evaporator for cooling the refrigeration case. The refrigeration system may further include a subcooler. A modulating evaporator pressure regulator valve is located downstream of the evaporator, on the return line between the subcooler and the compressor. The valve controls the suction gas pressure of the compressor which, in turn, controls the liquid temperature of the refrigerant entering the evaporators. The modulation of the pressure regulator valve is dependent on the dew point of the store and/or the temperature of the liquid entering the evaporators.

Abstract: An air conditioner having a permanent magnet electric motor with a high output power characteristic in a cooling and heating range and a high output characteristic even in defrosting operation in a high-speed range.