Systems and methods for providing hot water to a commercial dishwasher are provided. A first heat exchanger is provided in a first enclosure, and is used to heat water from a cold water source. The heated water is provided to the commercial dishwasher for use. A second heat exchanger is provided in a second enclosure, and is used to collect waste heat from the wastewater of the commercial dishwasher. A refrigerant coil loop passes through the first heat exchanger and the second heat exchanger, and allows for the use of the waste heat. The first heat exchanger is a condenser provided within a condenser chamber, the condenser connected to a compressor. The second heat exchanger is an evaporator within an evaporator chamber, the evaporator connected to an expansion valve.

Disclosed is a system for independently controlling the climate within a primary zone and at least one secondary zone of a building. The system comprises a primary packaged unit comprising a primary indoor coil and a primary variable speed indoor fan blowing over the primary indoor coil to serve the primary zone of the building. The system further comprises a secondary unit comprising a secondary indoor coil circulating the refrigerant and a secondary variable speed indoor fan blowing over the secondary indoor coil to serve a secondary zone of the building. The primary unit and the at least one secondary unit shares a common variable speed compressor, outdoor coil, and an outdoor fan that are disposed within the primary unit. First and second solenoid valves in the primary unit selectively control refrigerant flow to the primary and secondary units to enable independent control of the zones.

An HVAC system includes a blower, a variable-speed compressor, an indoor air temperature sensor that measures an indoor air temperature (IAT) of an enclosed space, a discharge air temperature sensor that measures a discharge air temperature (DAT) of the flow of air from an evaporator, and a controller. The controller stores an indoor temperature setpoint and a default discharge air temperature setpoint. The controller receives the IAT and the DAT. The controller determines that the IAT is not within a threshold range of the indoor temperature setpoint. The controller then determines an adaptive discharge air temperature setpoint. The controller determines a compressor speed at which to operate the variable-speed compressor based on the adaptive discharge air temperature setpoint. The controller causes the variable-speed compressor to operate at the determined compressor speed.

When intended to increase a refrigerant discharge capacity of a compressor in an ejector refrigeration cycle device at start-up of the compressor, the refrigerant discharge capacity is increased in such a manner that an increase amount in the refrigerant discharge capacity of the compressor per predetermined time period is lower than a maximum capacity increase amount per predetermined time period enabled by the compressor. Thus, even if a gas-liquid two-phase refrigerant flows into a refrigerant inflow passage forming a swirling-flow generating portion, the flow velocity of the gas-liquid two-phase refrigerant is prevented from becoming high, so that it can reduce friction noise that would be caused when the gas-liquid two-phase refrigerant circulates through the refrigerant inflow passage, further suppressing the generation of noise from the ejector.

A refrigeration system is provided that can be used to cool a plant growth chamber. The refrigeration system can include a compressor to compress refrigerant, a condenser to condense refrigerant, a compressed refrigerant line running from the compressor to the condenser, a throttling device, a condensed refrigerant line running from the condenser to the throttling device, an evaporator to evaporate liquid refrigerant, a throttled refrigerant line running from the throttling device to the evaporator, an evaporated refrigerant line running from the evaporator to the compressor, and, a by-pass line connected to the compressed refrigerant line after the condenser and running to the evaporator. A hot gas proportional valve provided inline of the by-pass line and a liquid proportional valve provided inline of the condensed refrigerant line are used to control the flow of refrigerant through the by-pass line.

In the case of a heating operation in which a use side heat exchanger functions as a condenser when the outside air has a predetermined low temperature, a low-outside-air-temperature heating operation start mode is executed in which, while a refrigerant, as discharged from a compressor, flows into the use side heat exchanger, the refrigerant is supplied to the injection port of the compressor via an injection pipe and a part of a refrigerant that is accumulated in an accumulator is supplied to the compressor via a connecting pipe, and thereafter a low-outside-air-temperature heating operation mode is executed in which the refrigerant, as discharged from the compressor, is supplied to the injection port of the compressor via the injection pipe while flowing into the use side heat exchanger.

There is disclosed an air-conditioning device of a so-called heat pump system which acquires comfortable heating in a vehicle interior by preventing or inhibiting frost formation to an outdoor heat exchanger. In a vehicular air-conditioning device 1, a controller calculates a requested refrigerant evaporation temperature in non-frosting TXObaseQtgt which is a refrigerant evaporation temperature of an outdoor heat exchanger 7 when a required heating capability Qtgt as a heating capability required for a radiator 4 is realized in non-frosting of the outdoor heat exchanger 7, and the controller controls heating by the radiator 4 and heating by a heating medium-air heat exchanger 40 of a heating medium circulating circuit 23 on the basis of the requested refrigerant evaporation temperature in non-frosting TXObaseQtgt and a frost point Tfrost to achieve the required heating capability Qtgt without causing frost formation to the outdoor heat exchanger 7.

An ejector-type refrigeration cycle has a compressor, an ejector module, a discharge capacity control section, and a pressure difference determining section. The ejector module has a body providing a gas-liquid separating space. The pressure difference determining section determines whether a low pressure difference operating condition is met. The low pressure difference operating condition is an operating condition in which a pressure difference obtained by subtracting a low-pressure side refrigerant pressure from a high-pressure side refrigerant pressure a predetermined reference pressure difference or lower. The body is provided with an oil return passage that guides a part of a liquid-phase refrigerant to flow from the gas-liquid separating space to a suction side of the compressor. The discharge capacity control section sets a refrigerant discharge capacity to be a predetermined reference discharge capacity or higher when the low pressure difference operating condition is determined to be met.

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 device includes a heating element, a temperature sensor, a first heat pump element, a first heating block, a second heating block and a controller. The heating element is to receive an energy of the controller and convert the energy into a first thermal energy provided to the first heating block. A sensing result is generated by the temperature sensor according to the first thermal energy. The first heat pump element is to receive the energy of the controller for generating a temperature difference. The first thermal energy is conducted to the first heat pump element for forming a second thermal energy. The second heating block is to receive the second thermal energy. The controller correspondingly outputs the energy to the heating element and the first heat pump element according to the sensing result, and thereby controls the first thermal energy and the temperature difference.