A heating, ventilation, and/or air conditioning (HVAC) system includes a refrigerant circuit configured to circulate refrigerant. The circuit includes a compressor, an indoor heat exchanger, an outdoor heat exchanger, and a reversing valve that transitions between a first configuration to direct the refrigerant from the compressor toward the outdoor heat exchanger and a second configuration to direct the refrigerant from the compressor toward the indoor heat exchanger. The system includes a compensator with a conduit that is part of the refrigerant circuit and configured to pass the refrigerant therethrough and a chamber disposed about the conduit. The chamber is also communicatively coupled to the refrigerant circuit, and configured to retain a portion of the refrigerant in the chamber. A coil assembly plate of the indoor heat exchanger or the outdoor heat exchanger includes a receptacle configured to receive the refrigerant charge compensator.

A variable refrigerant volume system includes: a compressor; a four-way valve; an indoor unit; a liquid tube, the first end thereof being connected to the indoor unit, the second end thereof being connected to the third valve port of the four-way valve, and a condenser being provided on the liquid tube; a low pressure air pipe, the first end thereof being connected to the indoor unit, and the second end thereof being connected to the fourth valve port of the four-way valve; a refrigerant adjustment tank, the first port thereof being connected to the liquid tube, the second port thereof being connected to the low pressure air pipe, and the third port thereof optionally communicating with the liquid tube or the low pressure air pipe.

An air conditioner and a method of controlling an air conditioner are provided. The air conditioner may include a compressor, an accumulator that recovers a liquid refrigerant contained in a refrigerant flowing into the compressor, an outdoor heat exchanger that performs heat exchange of air using the refrigerant, an outdoor unit fan that supplies outside air to the outdoor heat exchanger and discharges heat-exchanged air, a refrigerant charging pipe connected to a refrigerant pipe and allowing the refrigerant to the additionally introduced from the outside, a refrigerant charging valve installed in the refrigerant sharping pipe to open and close the refrigerant charging pipe, and a controller that sets an operation mode so as to operate in a cooling operation or a heating operation upon setting of a refrigerant charging mode, sets an operation frequency of the compressor in accordance with a load of an indoor unit upon the setting of the refrigerant charging mode to allow the compressor to operate at the set operation frequency during the refrigerant charging, and calculates an amount of refrigerant in order to stop the refrigerant charging when a predetermined reference value is reached.

The various embodiments described herein include methods, devices, and systems for determining refrigerant charge level. In one aspect, a refrigeration system includes: (1) a compressor to compress a refrigerant; (2) a condenser disposed downstream of the compressor to condense the refrigerant; (3) an evaporator disposed downstream of the condenser to vaporize the refrigerant; (4) refrigerant lines fluidly connecting the compressor, the condenser and the evaporator in series to form a refrigerant circuit for circulating the refrigerant; (5) at least one sensor configured to measure temperature and pressure of the refrigerant in the refrigerant circuit; and (6) a controller communicatively coupled to the at least one sensor and configured to: (a) determine a sub-cooling level or super-heating level based on the temperature and/or pressure measured by the at least one sensor; and (b) facilitate operation of the refrigeration system based on the sub-cooling level or the super-heating level.

The refrigeration system includes a compressor, a condenser, an evaporator, one or both of a receiver drier unit and an accumulator unit fluidly connected by refrigerant lines to form a refrigerant circuit. The receiver drier unit includes a receiver drier and a first sensor, and the accumulator unit includes an accumulator and a second sensor. A controller is electrically connected to the first and second sensors and in some cases electrically connected to an electrical valve. The electrical valve is fluidly connected to a refrigerant reservoir. The controller determines the refrigerant charge level, and selectively controls the electrical valve to allow the refrigerant to flow from the refrigerant reservoir to the refrigerant circuit when the refrigerant charge level is below the predetermined refrigerant charge level.

A gas replacement method for an expander of a cryocooler, the expander including an expander cylinder, a pressure switching valve that switches a pressure inside the expander cylinder, a connection flow path from the pressure switching valve to the expander cylinder, and an expander motor that drives the pressure switching valve, includes connecting a nonflammable gas source to the connection flow path or the expander cylinder, and purging a residual gas in the expander cylinder with a nonflammable gas from the nonflammable gas source while the expander motor is stopped.

Gas vaporizer for flashing liquid to vapor received from a source prior to introduction into a compressor or the like, such as in air conditioning or refrigeration systems. In certain embodiments the vaporize includes an adapter member for connection to a liquid source, a connector member having a plurality of flow passages for facilitating the transfer of heat to fluid present therein to vaporize the same, a body portion providing visual access such as via one or more sight glasses to an internal chamber therein for visual confirmation that liquid has been vaporized, and a hose connecting member for connection to a point of destination such as a compressor. In certain embodiments, the connector has an axial bore containing a high thermal conductive material.

The refrigeration system includes a compressor, a condenser, an evaporator, one or both of a receiver drier unit and an accumulator unit fluidly connected by refrigerant lines to form a refrigerant circuit. The receiver drier unit includes a receiver drier and a first sensor, and the accumulator unit includes an accumulator and a second sensor. A controller is electrically connected to the first and second sensors and in some cases electrically connected to an electrical valve. The electrical valve is fluidly connected to a refrigerant reservoir. The controller determines the refrigerant charge level, and selectively controls the electrical valve to allow the refrigerant to flow from the refrigerant reservoir to the refrigerant circuit when the refrigerant charge level is below the predetermined refrigerant charge level.

Gas vaporizer for flashing liquid to vapor received from a source prior to introduction into a compressor or the like, such as in air conditioning or refrigeration systems. In certain embodiments the vaporize includes an adapter member for connection to a liquid source, a connector member having a plurality of flow passages for facilitating the transfer of heat to fluid present therein to vaporize the same, a body portion providing visual access such as via one or more sight glasses to an internal chamber therein for visual confirmation that liquid has been vaporized, and a hose connecting member for connection to a point of destination such as a compressor. In certain embodiments, the connector has an axial bore containing a high thermal conductive material.

An apparatus for transferring a fluid from and/or to a system, e.g., an air conditioning system, includes a main compartment having at least one pumping device for pumping the fluid from/to the system, an interface module having at least one gauge which is configured for displaying the pressure of the fluid, and a fluid connection fluidly connecting the gauge to the main compartment. The fluid connection is formed in a double conduit design in order to prevent any leakage of the fluid from the fluid connection.