A system includes a dynamic compressor and a controller having a processor and a memory. The compressor includes a first compressor stage having a first variable inlet guide vane (VIGV) and a second compressor stage having a second VIGV. The memory stores instructions that program the processor to operate the compressor at a current speed, a first position of the first VIGV, and a second position of the second VIGV to compress the working fluid, and to determine if a condition is satisfied. If the condition is not satisfied, the processor is programmed to continue to operate the compressor at the current speed, the first position of the first VIGV, and the second position of the second VIGV. If the condition is satisfied, the processor is programmed to change the second position of the second VIGV to a third position and maintain the first position of the first VIGV.

A refrigerant system includes at least one compressor that compresses refrigerant and delivers it downstream to a heat rejection heat exchanger. The heat rejection heat exchanger is a microchannel heat exchanger. Refrigerant passes from the heat rejection heat exchanger downstream to an expansion device, from the expansion device through an evaporator, and from the evaporator back to the at least one compressor. A control operates at least one compressor and the expansion device to reduce pressure spikes at transient conditions.

A refrigerant system includes at least one compressor (54, 56) that compresses refrigerant and delivers it downstream to a heat rejection heat exchanger (26). The heat rejection heat exchanger is a microchannel heat exchanger. Refrigerant passes from the heat rejection heat exchanger downstream to an expansion device (60), from the expansion device through an evaporator (66), and from the evaporator back to the at least one compressor. A control (58) operates at least one compressor and the expansion device to reduce pressure spikes at transient conditions.

A refrigeration cycle device includes a compressor. The compressor includes a casing, a driving unit disposed in the casing, a compression unit coupled to the driving unit and configured to compress a refrigerant, and a valve configured to control a flow of the refrigerant in the casing. The valve includes a valve chamber including a main flow path in which the refrigerant is to flow, the main flow path including a refrigerant inlet and a refrigerant outlet. The valve also includes a floating body disposed in the valve chamber to open or close the main flow path, and a bypass flow path formed in the valve chamber and which is to be opened or closed by the floating body. When the driving unit is stopped and the bypass flow path is opened by the floating body, the refrigerant is to be detoured to the bypass flow path.

The present invention provides for a system for calibrating operation of a compressor unit in a heating, ventilation, and air conditioning (HVAC) system. A measuring device measures an operating parameter of the HVAC system at a position where the measuring device is mounted on a refrigerant line of the HVAC system. The measuring device switches states when the value of the measured operating parameter reaches a switching value. A controller estimates a value of the first operating parameter at the position where the first measuring device is mounted on the refrigerant line, and the controller determines whether the estimated first operating parameter is within a threshold percentage of the switching value.

The present invention provides for a system for calibrating operation of a compressor unit in a heating, ventilation, and air conditioning (HVAC) system. A measuring device measures an operating parameter of the HVAC system at a position where the measuring device is mounted on a refrigerant line of the HVAC system. The measuring device switches states when the value of the measured operating parameter reaches a switching value. A controller estimates a value of the first operating parameter at the position where the first measuring device is mounted on the refrigerant line, and the controller determines whether the estimated first operating parameter is within a threshold percentage of the switching value.

A method is provided for detecting in real-time a refrigerant charge loss in a refrigerant vapor compression system. If both a sensed evaporator outlet superheat exceeds a target evaporator outlet superheat by at least a preset amount of superheat and a sensed degree of openness of an electronic expansion valve exceeds a preset degree of openness for a preset time of period, and a sensed air temperature of either a flow of supply air having traversed the evaporator or a flow of return air returning to the evaporator is changing at a rate less than preset air temperature rate of change, a service alarm is generated indicating a loss of charge warning.

A refrigeration cycle device includes a compressor. The compressor includes a casing, a driving unit disposed in the casing, a compression unit coupled to the driving unit and configured to compress a refrigerant, and a valve configured to control a flow of the refrigerant in the casing. The valve includes a valve chamber including a main flow path in which the refrigerant is to flow, the main flow path including a refrigerant inlet and a refrigerant outlet. The valve also includes a floating body disposed in the valve chamber to open or close the main flow path, and a bypass flow path formed in the valve chamber and which is to be opened or closed by the floating body. When the driving unit is stopped and the bypass flow path is opened by the floating body, the refrigerant is to be detoured to the bypass flow path.

The present invention provides for a system for calibrating operation of a compressor unit in a heating, ventilation, and air conditioning (HVAC) system. A measuring device measures an operating parameter of the HVAC system at a position where the measuring device is mounted on a refrigerant line of the HVAC system. The measuring device switches states when the value of the measured operating parameter reaches a switching value. A controller estimates a value of the first operating parameter at the position where the first measuring device is mounted on the refrigerant line, and the controller determines whether the estimated first operating parameter is within a threshold percentage of the switching value.

The present invention provides for a system for calibrating operation of a compressor unit in a heating, ventilation, and air conditioning (HVAC) system. A measuring device measures an operating parameter of the HVAC system at a position where the measuring device is mounted on a refrigerant line of the HVAC system. The measuring device switches states when the value of the measured operating parameter reaches a switching value. A controller estimates a value of the first operating parameter at the position where the first measuring device is mounted on the refrigerant line, and the controller determines whether the estimated first operating parameter is within a threshold percentage of the switching value.