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 thermal energy system comprising a first thermal system having a heating demand, and a heat source connection system coupled to the first thermal system, the heat source connection system being adapted to provide selective connection to a plurality of heat sources for heating the first thermal system, the heat source connection system comprising a first heat exchanger system coupled to a first remote heat source containing a working fluid and a second heat exchanger system adapted to be coupled to ambient air as a second heat source, a fluid loop interconnecting the first thermal system, the first heat exchanger system and the second heat exchanger system, at least one mechanism for selectively altering the order of the first heat exchanger system and the second heat exchanger system in relation to a fluid flow direction around the fluid loop, and a controller for actuating the at least one mechanism.

A refrigeration system includes first and second compressors, a condenser, first and second evaporators, and a valve. The first compressor is fluidly connected to first suction and discharge lines. The second compressor is fluidly connected to second suction and discharge lines. The second suction line is fluidly connected to the first discharge line. The condenser receives refrigerant from the second compressor. The first evaporator receives refrigerant from the condenser and discharges refrigerant to the first suction line. The second evaporator receives refrigerant from the condenser and discharges refrigerant to the second suction line. The valve is disposed between the first evaporator and the first suction line. The first suction line receives refrigerant when the valve is in a first position. The second suction line receives refrigerant when the valve is in a second position. The first compressor is bypassed when the valve is in the second position.

A heat exchanger for a refrigerated merchandiser includes a fan housing having an asymmetrical configuration. The fan housing can include a first section with a first open outlet and a second section with a second open outlet. A first fan is positioned in the first section and configured to create a first airflow through the first open outlet. A second fan is positioned in the second section and configured to create a second airflow through the second open outlet. An evaporator is in fluid communication with the first open outlet and second open outlet. The first section is asymmetrical about a first section central axis and the second section is asymmetrical about a second section central axis.

Systems and methods for controlling pressure in a CO.sub.2 refrigeration system are provided. The pressure control system includes a pressure sensor, a gas bypass valve, a parallel compressor, and a controller. The pressure sensor is configured to measure a pressure within a receiving tank of the CO.sub.2 refrigeration system. The gas bypass valve is fluidly connected with an outlet of the receiving tank and arranged in series with a compressor of the CO.sub.2 refrigeration system. The parallel compressor is fluidly connected with the outlet of the receiving tank and arranged in parallel with both the gas bypass valve and the compressor of the CO.sub.2 refrigeration system. The controller is configured to receive a pressure measurement from the pressure sensor and operate both the gas bypass valve and the parallel compressor, in response to the pressure measurement, to control the pressure within the receiving tank.

A system and method are provided including a system controller for a refrigeration or HVAC system having a compressor rack with a compressor and a condensing unit with a condenser fan. The system controller monitors and controls operation of the refrigeration or HVAC system. A rack controller monitors and controls operation of the compressor rack and determines compressor rack power consumption data. A condensing unit controller monitors and controls operation of the condensing unit and determines condensing unit power consumption data. The system controller receives the compressor rack power consumption data and the condensing unit power consumption data, determines a total power consumption of the refrigeration or HVAC system, determines a predicted power consumption or a benchmark power consumption for the refrigeration system, compares the total power consumption with the predicted power consumption or the benchmark power consumption, and generates an alert based on the comparison.

An integrated system floods an air conditioning low side heat exchanger such that the air conditioning low side heat exchanger does not evaporate all the liquid refrigerant entering the air conditioning low side heat exchanger. As a result, both liquid and vapor refrigerant leave the air conditioning low side heat exchanger. The system includes an additional receiver that stores the refrigerant leaving the air conditioning low side heat exchanger. To prevent the liquid refrigerant in the receiver from overflowing, the liquid refrigerant in the receiver is used in a refrigeration system when the level of liquid refrigerant in the receiver exceeds a threshold (e.g., as detected by a sensor in the receiver).

A refrigerated display case includes a housing surrounding multiple shelves. An air distribution gap is defined behind the shelves. An air return passage is defined below the shelves. A radial cross-flow fan is disposed in a fan region of the air return passage. The radial cross-flow fan includes an output connected to the air distribution gap. A primary cooling microchannel heat exchanger is disposed in the fan region downstream of the radial cross-flow fan such that air output from the radial cross-flow fan to the air distribution gap passes through the primary cooling microchannel heat exchanger. A pre-cooler microchannel heat exchanger is disposed upstream of the primary cooling microchannel heat exchanger.

A heat pump system includes a first heat pump arrangement configured to operate with a first heat pump medium including CO2; a second heat pump arrangement configured to operate with a second heat pump medium including water; and a coupler for thermally coupling the first heat pump arrangement to the second heat pump arrangement.

A dual reclaim coil with a smart control application is provided that allows the refrigerant inlet to the HVAC unit switch between the two sides of the condenser for heat reclaim for refrigerants such as CO.sub.2 which have a relatively low critical temperature compared to hydrofluorocarbon refrigerants. Heat reclaim after the exit of gas from the condenser utilizes the high temperature and pressure of the condenser/gas cooler outlet while a CO.sub.2 refrigerant system is operating above critical point. This occurs in hot ambient conditions, when the need for heating in the space is not as great as in the wintertime and the available heat at the condenser/gas cooler's outlet is sufficient to satisfy the heating load. When the CO.sub.2 refrigerant system is operating below the critical point, heat reclaim is carried out at the compressor discharge.