A method for reducing sweating in a temperature-controlled display device includes receiving values of an ambient temperature, a door frame temperature, and relative humidity. The method can also include estimating a value of a dewpoint temperature using the values of the ambient temperature and the relative humidity. The method can also include determining control decisions for a door frame heater of the temperature-controlled display device using the value of the dewpoint temperature and the door frame temperature, and transitioning the door frame heater between an on-state and an off-state using the control decisions to maintain the value of the door frame temperature at or above the value of the dewpoint temperature.

A method for reducing sweating in a temperature-controlled display device includes receiving values of an ambient temperature, a door frame temperature, and relative humidity. The method can also include estimating a value of a dewpoint temperature using the values of the ambient temperature and the relative humidity. The method can also include determining control decisions for a door frame heater of the temperature-controlled display device using the value of the dewpoint temperature and the door frame temperature, and transitioning the door frame heater between an on-state and an off-state using the control decisions to maintain the value of the door frame temperature at or above the value of the dewpoint temperature.

The present invention provides a refrigerant composition comprising: (a) from about 65% by weight to about 90% by weight of HFO-1234ze(E); (b) from about 10% by weight to about 35% by weight of HFO-1336mzz (E); and optionally (c) from about 0% to about 4.4% by weight of HFC-227ea for use in a variety of refrigeration applications, including air conditioning and/or refrigeration and particularly cooling products such as fruits, vegetables and beverages without exposing those articles to temperatures below the freezing point of water.

Systems and methods are provided and include a case controller for a refrigeration case of a refrigeration system. The case controller is configured to: determine an evaporator saturated suction temperature (SST) of an evaporator of the refrigeration case; control an evaporator pressure regulator of the refrigeration system based on a comparison of the evaporator SST with an evaporator saturated suction temperature (SST) setpoint; receive an air temperature value from an air temperature sensor associated with the refrigeration case; determine whether the air temperature value is within a predetermined range of an air temperature setpoint; and adjust the SST setpoint in response to the air temperature value being outside of the predetermined range of the air temperature setpoint.

A transportation refrigeration system includes a compartment to be conditioned. A refrigeration circuit is associated with an enclosure including a compressor. A condenser and an expansion valve are upstream of a first evaporator and a second evaporator. The first evaporator is in parallel with the second evaporator. A first enclosure surrounds the first evaporator. The first enclosure includes a first refrigerant detection sensor in communication with a controller. A second enclosure surrounds the second evaporator. The second enclosure includes a second refrigeration detection sensor in communication with the controller.

Disclosed is a refrigeration system having: a steam ejector with an ejector outlet; and a passive flow trap connected to the ejector outlet.

A refrigeration system includes a primary refrigeration circuit configured to circulate a CO.sub.2 primary refrigerant and a secondary refrigeration circuit separate from the primary refrigeration circuit. The primary refrigeration circuit includes a compressor assembly, a condenser assembly, a receiver, and one or more refrigeration loads having an evaporator assembly. The secondary refrigeration circuit includes a thermal storage unit and a heat exchanger. The thermal storage unit contains a phase change material. The secondary refrigeration circuit is in thermal communication with the primary refrigeration circuit through the heat exchanger. The primary refrigerant includes a critical temperature. The primary refrigeration circuit is configured for subcritical operation. The primary refrigeration circuit and the secondary refrigeration circuit are configured such that the phase change material provides cooling to the primary refrigerant during a first operating condition. The phase change material is configured to maintain subcritical operation of the primary refrigeration circuit during the first operating condition when the primary refrigerant is above the critical temperature.

An apparatus includes a flash tank, a first low side heat exchanger, a second low side heat exchanger, a first compressor, a second compressor, an expansion valve, a desuperheater, a sensor, and a controller. The first compressor compresses a refrigerant from the second low side heat exchanger. The desuperheater removes heat from the refrigerant from the first compressor. The second compressor compresses a mixture of the refrigerant from the first low side heat exchanger and the refrigerant from the first compressor. The expansion valve, actionable by the sensor and the controller, controls a flow of the refrigerant to the first low side heat exchanger such that the flow of refrigerant to the first low side heat exchanger is increased when a temperature of the mixture exceeds a threshold.

An air conditioning apparatus is an air conditioning apparatus dedicated to cooling and includes a first circuit and a second circuit. The first circuit has an outdoor heat exchanger that cools a first refrigerant by outdoor air. In the second circuit, a first heat transfer medium that is cooled by exchanging heat with the first refrigerant that flows in the first circuit flows. The first refrigerant is a HFO refrigerant having a critical temperature higher than that of R32.

At least one heat-source side cycle and at least one load side cycle share a cascade heat exchanger. A total number of cycles provided by the at least one heat-source side cycle and the at least one load side cycle is three or more, such that there is a first cycle, a second cycle and a third cycle. The first cycle circulates a first refrigerant or heat medium. The second cycle circulates a second refrigerant or heat medium. The third cycle circulates a third refrigerant or heat medium. The first refrigerant or heat medium, the second refrigerant or heat medium, and the third refrigerant or heat medium are different from one another.