A heating, ventilation, and air conditioning system may include a refrigerant loop to circulate refrigerant, a first valve, a second valve, a sensor to measure parameters of the refrigerant, a refrigerant tank fluidly coupled to the refrigerant loop via the valves, and control circuitry communicatively coupled to the sensor, the first valve, and the second valve. The control circuitry may determine environmental conditions and detect whether an undercharge or overcharge condition is present in the refrigerant loop based at least in part on the environmental conditions and the measured parameters. The control circuitry may also instruct the first valve to open when the undercharge condition is detected to facilitate flowing refrigerant from the refrigerant tank into the refrigerant loop and instruct the second valve to open when the overcharge condition is detected to facilitate flowing refrigerant from the refrigerant loop into the refrigerant tank.

A dynamic receiver is included in parallel to an expander of a heating, ventilation, air conditioning, and refrigeration (HVACR) system. The dynamic receiver allows control of the refrigerant charge of the HVACR system to respond to different operating conditions. The dynamic receiver can be filled or emptied in response to the subcooling observed in the HVACR system compared to desired subcooling for various operating modes. The HVACR system can include a line directly conveying working fluid from compressor discharge to the dynamic receiver to allow emptying of the dynamic receiver to be assisted by injection of the compressor discharge.

A dynamic refrigeration system may automatically, at pre-determined time periods on-the-fly, adjust a refrigerant system's refrigerant pressures to predetermined optimal efficiency pressures as the internal and external heat loads change over a range. This may result in the refrigerant system pressures closely operating within a range of predetermined optimal efficiency pressures. This system may automatically instantaneously fine tune and balance on all air conditioning, heat pump, and refrigeration systems as the internal and external heat loads are continuously changing dynamically. The system may include a small liquid refrigerant pump and refrigerant storage tank, one or more wired or wireless pressure transducers and temperature sensors, and a brain to make decisions to keep the system instantaneously set at factory specs all the time. The system may include a wireless communication means so it can instantaneously report its operating condition, loads, and cost of operating.

A diagnostic system for a refrigeration system including a condenser is provided. The diagnostic system may include a controller determining a subcooling temperature of the refrigeration system, an approach temperature of the condenser, and a condenser temperature difference of the condenser. The controller may determine at least one of a fault condition of the refrigeration system and a charge of the refrigeration system based on the subcooling temperature, the approach temperature, and the condenser temperature difference.

A microchannel heat exchanger has an upper portion connected in fluid communication with a header, a lower portion connected in fluid communication with the header at a location that is vertically lower on the header than the upper portion, and a sight glass on the header. The sight glass can be horizontally aligned with a top of the second portion. The sight glass can be served as a visual aid when charging the microchannel heat exchanger with a refrigerant at a predetermined level. When an indicator indicates that refrigerant is mixed vapor and liquid, refrigerant can be added into the microchannel heat exchanger. When the indicator indicates that the refrigerant is liquid, the charging process can be stopped.

An air conditioner and a control method of an air conditioner are provided. The air conditioner includes an outdoor unit, an indoor unit, a refrigerant circulation loop, and a controller. The controller is configured to determine whether the air conditioner is operating in a cooling mode; obtain a first target supercooling degree in a first standard condition if it determined that the air conditioner is operating stably in the cooling mode; convert a supercooling degree in a current condition into a supercooling degree in the first standard condition; obtain a first refrigerant amount difference according to the first target supercooling degree, the supercooling degree in the first standard condition, an outdoor unit internal volume in the first standard condition, and an outdoor unit internal volume in the current condition; and determine a refrigerant amount of the air conditioner according to the first refrigerant amount difference.

A heat-pump circuit may include an indoor heat exchanger, an outdoor heat exchanger, a compressor adapted to circulate a working fluid between the indoor and outdoor heat exchangers, and an expansion device disposed between the indoor and outdoor heat exchangers. A monitor for the heat-pump system may include a return-air temperature sensor, a supply-air temperature sensor, and a processor. The return-air temperature sensor may be adapted to measure a first air temperature of air upstream of the indoor heat exchanger. The supply-air temperature sensor may be adapted to measure a second air temperature of air downstream of the indoor heat exchanger. The processor may be in communication with the return-air temperature sensor and the supply-air temperature sensor. The processor may be programmed to determine a working-fluid-charge condition of the heat-pump system based on the first and second air temperatures.

An air-conditioning apparatus determines whether or not to permit an air-conditioning operation based on refrigerant amount information stored in an outdoor unit and installation height information stored in an indoor unit.

The present disclosure relates to a passive refrigerant charge management system including a charge vessel configured to fluidly couple to a refrigerant circuit. The charge vessel includes a first portion having a compressible fluid and a second portion configured to contain refrigerant of the refrigerant circuit, wherein an amount of the refrigerant contained in the second portion is based on a first pressure of the refrigerant within the refrigerant circuit and a second pressure of the compressible fluid.

A system for measuring and recharging an air conditioning system includes a vent sensor configured to be coupled to an outlet vent of an air conditioning system. The vent sensor is configured to measure at least one parameter of an air flow from the outlet vent. A processor is in signal communication with the vent sensor. The processor is configured to receive the at least one parameter of the air flow and determine a current refrigerant level of the air conditioning system.