A system includes a converter and a controller to control a compressor and operates without receiving power supply from a thermostat. The converter receives a demand signal from the thermostat that is used to power the controller and charge a capacitor. When the thermostat de-asserts the demand signal, the charged capacitor powers the controller, which saves system parameters in a nonvolatile memory and enters a power save mode. The life of the nonvolatile memory is extended by alternately storing the system parameters in different memory locations. The system normalizes outdoor ambient temperature (OAT) during a demand cycle. The system determines OAT slope, which is used to select durations to operate the compressor at different capacities, by performing time based calculations during a demand cycle, demand cycle based calculations at the start of a demand cycle, or time and demand cycle based calculations during a demand cycle.

Provided is an air-conditioning apparatus including a plurality of indoor units for an outdoor unit, which is capable of determining whether there is occurrence of frost formation on the outdoor unit during a heating operation so as to enable a transition to a defrosting operation at an appropriate timing. Each of the indoor units is configured to transmit an operating-state notification for notifying a self-operating state to the outdoor unit. The outdoor unit is configured to determine the number of indoor units performing the heating operation among the plurality of indoor units based on the operating-state notifications, and determine the occurrence of the frost formation after elapse of a preset time period from a time at which the number of the indoor units performing the heating operation changes.

Systems and methods are provided for detecting low refrigerant charge in a refrigeration system. Specifically, the present invention provides systems and methods for comparing refrigerant charges of the refrigeration system during at least substantial shut down.

The refrigerant circulation direction is switched between first and second circulation directions. In the first circulation direction, the refrigerant is circulated in order of a first heat exchanger, a compressor, a second heat exchanger, and a first decompressor, and circulated in order of the first heat exchanger, the compressor, a third heat exchanger, and a second decompressor. A controller identifies a specific heat exchanger from among the second heat exchanger and the third heat exchanger. When an elapsed time from activation of the compressor is shorter than a reference time, the controller makes an opening degree of a specific decompressor that communicates with the specific heat exchanger larger than an opening degree of the decompressor that is among the first decompressor and the second decompressor and different from the specific decompressor, and sets the refrigerant circulation direction to the second circulation direction opposite to the first circulation.

An air conditioning system includes a storage medium and an air conditioning system, for a three-pipe air conditioning system, the three-pipe air conditioning system includes a compressor, an outdoor heat exchanger, an indoor heat exchanger, a gas-liquid separator, a first pipeline, a second pipeline and a third pipeline; the oil return control method comprises the following steps: controlling the compressor to operate at a first frequency in a refrigerating mode; judging whether the operation duration of the refrigerating mode reaches a first preset time or not; if so, the air conditioning system enters an oil return state, and the compressor, the third pipeline, the second pipeline and the gas-liquid separator are controlled to be communicated in sequence to form a refrigerant circulation loop.

A refrigerator and a method for controlling the same are disclosed. A refrigerator includes a timer for measuring an interval of one hour after power is supplied to the refrigerator, a door opening/closing sensor for sensing opening and closing of a door, a storage unit for storing information whether door is opened in a sector defined as one hour by the timer and at least 7 sector units each having 24 consecutive sectors, and a control unit for predicting a refrigerator use pattern in 24 sectors by overlapping 7 sector units, performing a normal operation mode to maintain a storage compartment at a first desired temperature in a sector in which door opening is predicted, and performing a power-saving operation mode to maintain the storage compartment at a second desired temperature higher than the first desired temperature in a sector in which door opening is not predicted.

An air conditioner unit includes a refrigeration loop including a condenser and an evaporator, a compressor for circulating refrigerant, and an electronic expansion valve. A controller monitors an operating superheat of the refrigerant across the evaporator, identifies a superheat fault condition based on at least one of the operating superheat, a target valve position of the electronic expansion valve, or a compressor speed, stops the compressor in response to identifying the superheat fault condition, and initiates a calibration process of the electronic expansion valve.

A vehicle, a refrigerator for a vehicle, and a method for controlling a refrigerator for a vehicle are provided. The method for controlling the refrigerator for the vehicle includes turning on a switch of the refrigerator for the vehicle, measuring a temperature of an interior of the refrigerator for the vehicle a first time, measuring a temperature of the interior of the refrigerator for the vehicle again a second time after a predetermined time has elapsed from the first time, determining a temperature change of the interior of the refrigerator from the first time to the second time, and operating the refrigerator for the vehicle in a quench mode in which the temperature in the interior of the refrigerator is rapidly lowered, unlike a normal mode, if the temperature change in the interior of the refrigerator is in a positive direction.

A refrigeration cycle apparatus includes a refrigerant circuit that is formed by connecting a compressor, a flow passage switching device, an outdoor heat exchanger, an expansion unit, and an indoor heat exchanger via pipes, and through which refrigerant flows, an outdoor air-sending device configured to blow outdoor air to the outdoor heat exchanger, an outdoor air temperature detector configured to detect a temperature of the outdoor air, and a controller configured to control an operation of the outdoor air-sending device.

A method is provided for managing a flooded start of a compressor in a vapor compression system. Following an initial bump start, a determination is made as to whether working fluid in a liquid state remains in the sump of the compressor. If working fluid in a liquid state remains in the compressor sump, an additional bump start of the compressor is completed, followed by another determination as to whether working fluid in a liquid state still remains in the compressor sump. If working fluid in a liquid state remains in the compressor sump, another bump start of the compressor is initiated and the sequence repeated until no working fluid in the liquid state remains in the compressor sump. A normal start of the compressor may be initiated after determining no working fluid in the liquid state remains in the compressor sump.