A chiller system includes a mechanical-cooling circuit configured to circulate a refrigerant through an evaporator of the mechanical-cooling circuit, where the evaporator is configured to cool a conditioning fluid with the refrigerant. The chiller system also includes a free-cooling circuit configured to circulate the refrigerant through a heat exchanger of the free-cooling circuit, where the heat exchanger is configured to cool the conditioning fluid with the refrigerant. The chiller system also includes a distribution header having a first inlet configured to receive the refrigerant from the mechanical-cooling circuit, a second inlet configured to receive the refrigerant from the free-cooling circuit, and an internal volume fluidly coupled to the first inlet and the second inlet. A fan coil unit of the chiller system is configured to receive the refrigerant from the internal volume of the distribution header.

A chiller system includes a mechanical-cooling circuit configured to circulate a refrigerant through an evaporator of the mechanical-cooling circuit, where the evaporator is configured to cool a conditioning fluid with the refrigerant. The chiller system also includes a free-cooling circuit configured to circulate the refrigerant through a heat exchanger of the free-cooling circuit, where the heat exchanger is configured to cool the conditioning fluid with the refrigerant. The chiller system also includes a distribution header having a first inlet configured to receive the refrigerant from the mechanical-cooling circuit, a second inlet configured to receive the refrigerant from the free-cooling circuit, and an internal volume fluidly coupled to the first inlet and the second inlet. A fan coil unit of the chiller system is configured to receive the refrigerant from the internal volume of the distribution header.

An air-conditioning device includes a heater unit that heats the air to be lead to a vehicle cabin using the heat of the refrigerant compressed by a compressor, a liquid receiver arranged at the downstream side of an outside heat exchanger, a liquid receiver separating the refrigerant lead from the outside heat exchanger into a liquid-phase refrigerant and a gaseous-phase refrigerant and storing the liquid-phase refrigerant, and a restrictor mechanism provided between the heater unit and the outside heat exchanger, the restrictor mechanism decompressing and expanding the refrigerant. When there is a dehumidification request, the operation mode is temporarily switched from a dehumidifying cabin-heating mode which evaporates the refrigerant by an evaporating unit and radiates heat by the heater unit in the state in which the restrictor mechanism restricts the flow of the refrigerant, to the cabin-cooling mode which evaporates the refrigerant by the evaporating unit while promoting the storage of the liquid-phase refrigerant in the liquid receiver.

A refrigerating apparatus may include a main body having an interior space in which an article is accommodated, a door configured to open and close an opening of the main body, a compressor configured to compress a non-azeotropic mixed refrigerant, a condenser configured to condense the compressed non-azeotropic mixed refrigerant, a hotline provided at a contact portion between the main body and the door through which the condensed non-azeotropic mixed refrigerant flows, an expander configured to expand the non-azeotropic mixed refrigerant, heat of which is radiated by the hotline, and an evaporator configured to evaporate the expanded non-azeotropic mixed refrigerant to supply cold air to the interior space. According to such structure, even when the non-azeotropic mixed refrigerant is used, a function of the hotline to prevent dew formation may be normally performed with hot refrigerant.

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 is aimed to use 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. This also mitigates space overcooling, while increasing the CO.sub.2 transcritical system's efficiency by subcooling the refrigerant for applications involving dehumidification HVAC systems which often results in a phenomenon called “overcooling” during the dehumidification season.

A method for defrosting an external heat exchanger, operated as an air heat pump evaporator, of a cooling system for a motor vehicle. The cooling system includes a refrigerant compressor connected to a primary and secondary section; an external heat exchanger; an evaporator; a heating register; a primary section valve which is closed in the air heat pump operation; and a secondary section valve which is open in the air heat pump operation. The method includes closing of the secondary section valve; opening of the primary section valve, so that refrigerant flows directly from the refrigerant compressor to the external heat exchanger; and setting an inlet-side pressure level of the refrigerant on the external heat exchanger to a target pressure which corresponds to a condensation temperature (Tkond) of the refrigerant in the range: 2° C. ≤ Tkond ≤ 20° C., in particular 4° C. ≤ Tkond ≤ 10° C.

A dehumidification system includes a compressor, a primary evaporator, a primary condenser, a secondary evaporator, and a secondary condenser. The secondary evaporator receives an inlet airflow and outputs a first airflow to the primary evaporator. The primary evaporator receives the first airflow and outputs a second airflow to the secondary condenser. The secondary condenser receives the second airflow and outputs a third airflow to the primary condenser. The primary condenser receives the third airflow and outputs a dehumidified airflow. The compressor receives a flow of refrigerant from the primary evaporator and provides the flow of refrigerant to the primary condenser.

A dehumidification system includes a compressor, a primary evaporator, a primary condenser, a secondary evaporator, and a secondary condenser. The secondary evaporator receives an inlet airflow and outputs a first airflow to the primary evaporator. The primary evaporator receives the first airflow and outputs a second airflow to the secondary condenser. The secondary condenser receives the second airflow and outputs a third airflow to the primary condenser. The primary condenser receives the third airflow and outputs a dehumidified airflow. The compressor receives a flow of refrigerant from the primary evaporator and provides the flow of refrigerant to the primary condenser.

A dehumidification system includes a compressor, a primary evaporator, a primary condenser, a secondary evaporator, a secondary condenser, and a water pump. The secondary evaporator receives an inlet airflow and outputs a first airflow to the primary evaporator. The primary evaporator receives the first airflow and outputs a second airflow to the secondary condenser. The secondary condenser receives the second airflow and outputs a dehumidified airflow. The compressor receives a flow of refrigerant from the primary evaporator and provides the flow of refrigerant to the primary condenser. The primary condenser receives the flow of refrigerant and outputs the flow of refrigerant at a lower temperature through heat transfer with a flow of fluid. The flow of fluid is directed, by the water pump, to a heat exchanger or an external source, where heat is rejected from the flow of fluid.

A dehumidification system includes a compressor, a primary evaporator, a primary condenser, a secondary evaporator, a secondary condenser, and a water pump. The secondary evaporator receives an inlet airflow and outputs a first airflow to the primary evaporator. The primary evaporator receives the first airflow and outputs a second airflow to the secondary condenser. The secondary condenser receives the second airflow and outputs a dehumidified airflow. The compressor receives a flow of refrigerant from the primary evaporator and provides the flow of refrigerant to the primary condenser. The primary condenser receives the flow of refrigerant and outputs the flow of refrigerant at a lower temperature through heat transfer with a flow of fluid. The flow of fluid is directed, by the water pump, to a heat exchanger or an external source, where heat is rejected from the flow of fluid.