A refrigeration apparatus includes: a refrigerant circuit through which refrigerant circulates; a controller to execute a plurality of refrigerant shortage sensing functions of sensing a shortage of an amount of the refrigerant; and an input device through which an operation mode to be set is input into the controller. The operation mode includes: a first mode in which energy-saving performance is emphasized; and a second mode in which the refrigeration apparatus is permitted to operate in a range in which reliability is ensured. In accordance with the operation mode set through the input device, the controller determines which one of sensing results obtained by the refrigerant shortage sensing functions is enabled and which one of sensing results obtained by the refrigerant shortage sensing functions is disabled. When a sensing result determined to be enabled shows a refrigerant shortage, the controller gives a notification about the refrigerant shortage.

A modulating refrigeration system includes an evaporation unit and a condensing unit. The evaporation unit generates a first output airflow comprising a lower temperature, a lower relative humidity, or both than a first supply airflow and directs the first output airflow into a building. The condensing unit generates a second output airflow at a higher temperature than a second supply airflow and discharges the second output airflow to an unconditioned space. The evaporation unit comprises a first valve operable to direct a portion of refrigerant to a secondary evaporator and primary evaporator or to direct the entire flow of refrigerant to the primary evaporator and bypassing the secondary evaporator.

An ejector refrigeration cycle device includes: a radiator that dissipates heat from a refrigerant discharged from a compressor; an ejector module that decompresses the refrigerant cooled by the radiator; and an evaporator that evaporates a liquid-phase refrigerant separated in a gas-liquid separation space of the ejector module. A grille shutter is disposed as an inflow-pressure increasing portion between the radiator and a cooling fan blowing the outside air toward the radiator. The grille shutter is operated to decrease the volume of the outside air to be blown toward the radiator when an outside air temperature is equal to or lower than a reference outside air temperature, thereby increasing the pressure of the inflow refrigerant to flow into a nozzle passage of the ejector module.

A heating system including a condenser and an evaporator. A compressor is along a refrigerant line and is configured to compress refrigerant flowing to the condenser. A first valve is along the refrigerant line between the compressor and the condenser. A controller is configured to partially close the first valve when a measured temperature is below a threshold to increase discharge pressure of refrigerant compressed by the compressor and increase heat dissipation of the condenser.

There is disclosed an air-conditioning apparatus for vehicle which is capable of selecting an appropriate operation mode while inhibiting the operation mode from being unnecessarily changed, and achieving rapid and stable vehicle interior air conditioning. A controller has respective operation modes of a heating mode, a dehumidifying and heating mode, a dehumidifying and cooling mode, and a cooling mode, and selects and executes these operation modes. The controller has a dehumidifying and heating mode maximum radiator temperature MAP and a dehumidifying and cooling mode maximum radiator temperature MAP. The controller selects an operation mode in which a radiator target temperature TCO is achievable by heat radiation in a radiator 4 with reference to each MAP, on startup or at a time of change of the operation mode.

A vehicle air conditioning apparatus can ensure that the temperature of the air supplied to the vehicle interior is a preset temperature by securing the quantity of heat release for the radiator during a cooling and dehumidifying operation. The valve opening of the condensing pressure regulating part of the first control valve is smaller when the calculated opening SW of the air mix damper is equal to or more than the predetermined value than when the opening SW is smaller than the predetermined value. Accordingly, when the quantity of heat release is not sufficient in the radiator, it is possible to increase the condensing pressure of the refrigerant in the radiator to raise the temperature of the refrigerant in the radiator. Consequently, it is possible to secure the amount of heating, and therefore to ensure that the temperature of the air supplies to the vehicle interior is a preset temperature.

A system includes a high side heat exchanger, a flash tank, a first load, a second load, a first compressor, and a heat exchanger. The flash tank is configured to store the refrigerant from the high side heat exchanger. The first load is configured to use the refrigerant from the flash tank to remove heat from a first space proximate to the first load. The second load is configured to use the refrigerant from the flash tank to remove heat from a second space proximate to the second load. The first compressor is configured to compress the refrigerant from the first load. The heat exchanger is configured to transfer heat from the refrigerant from the first compressor and the second load to the refrigerant from the high side heat exchanger, and direct the refrigerant from the first compressor and the second load to a second compressor.

An HVAC system includes an indoor unit having a return air duct and a supply air duct in an enclosed space. The HVAC system includes an outdoor unit having a variable-speed condenser fan. A first temperature sensor is disposed in at least one of the return air duct, the supply air duct, or an enclosed space. A controller is operatively coupled to the first temperature sensor, and the variable-speed condenser fan. The controller is configured to determine whether at least one of over-cooling or over-heating of air in the enclosed space is occurring. Responsive to a determination that at least one of over-cooling or over-heating of air in the enclosed space is occurring, the controller adjusts a speed of the variable-speed condenser fan.

A mechanical subcooling system operatively connectable to a transcritical R-744 refrigeration system resulting in an energy efficiency ratio of a level comparable to that of refrigeration systems using common refrigerants. Mechanical subcooling increases the refrigeration capacity without increasing the power consumption of the refrigeration system's compressors. The compressors used to provide the refrigeration capacity for the subcooling process operate at much more favorable conditions, thus having a very high energy efficiency ratio. The result is higher refrigeration capacity and lower power consumption.

An HVAC system includes an indoor unit having a return air duct and a supply air duct in an enclosed space. The HVAC system includes an outdoor unit having a variable-speed condenser fan. A first temperature sensor is disposed in at least one of the return air duct, the supply air duct, or an enclosed space. A controller is operatively coupled to the first temperature sensor, and the variable-speed condenser fan. The controller is configured to determine whether at least one of over-cooling or over-heating of air in the enclosed space is occurring. Responsive to a determination that at least one of over-cooling or over-heating of air in the enclosed space is occurring, the controller adjusts a speed of the variable-speed condenser fan.