A heat pump system includes a first unit; a second unit connected to a first flow path of the first unit; and a third unit connected to a second flow path of the first unit and connected to the second unit. The heat pump system can operate in a cooling and water heating mode and a heating and water heating mode, wherein, in the cooling and water heating mode, the heat pump system is configured to switch a switching assembly to a first position and connect the at least one first heat exchangers and the second heat exchanger in series; in the heating and water heating mode, the heat pump system is configured to switch the switching assembly to a second position and connect the second heat exchanger and the at least one third heat exchangers in parallel.

A flash gas bypass system includes a separation assembly having an inlet configured to receive a refrigerant flow from an expansion valve. A bypass conduit is coupled to a first port of the separation assembly and configured to receive a first portion of the refrigerant flow via the first port, where the first portion of the refrigerant flow includes flash gas. A second port of the separation assembly is coupled to an outlet conduit in fluid communication with an evaporator. The outlet conduit is configured to receive the second portion of the refrigerant flow via the second port and direct the second portion of the refrigerant flow toward the evaporator, where the second portion of the refrigerant flow includes liquid refrigerant. A filter is configured to redirect droplets captured by the filter from the first portion of the refrigerant flow into the second portion of the refrigerant flow.

An air-conditioning apparatus includes: a heat source unit that generates a heating energy or a cooling energy that is transferred to refrigerant; a heat-use unit that causes the refrigerant to transfer the heating energy or the cooling energy to a heat load through heat exchange between the refrigerant and the heat load; a plurality of return pipes arranged parallel to each other and connecting the heat source unit and the heat-use unit to allow the refrigerant to flow therein from the heat-use unit to the heat source unit; an opening and closing device provided at at least one of the return pipes to control a flow rate of refrigerant; and a controller that opens the opening and closing device in a cooling operation, and closes the opening and closing device in a heating operation.

An outdoor system for an air conditioner may include at least one outdoor unit, the at least one outdoor unit including a compressor; an outdoor heat exchanger; a pair of two-stage compression lines that extends to outside of the outdoor system; a pair of connection lines that extends to the outside of the outdoor system and communicates with an indoor unit; and multiple valves that open/close the pair of two-stage compression lines and the pair of connection lines when the outdoor system is operated in a one-stage heating mode or a two-stage heating mode.

A multi-air conditioner for cooling and heating is provided to remove latent heat and sensible heat by using a single outdoor unit. The multi-air conditioner includes: at least one indoor unit installed in a room, that comprises an indoor heat exchanger and an indoor expansion valve; an outdoor unit connected to the indoor unit via a refrigerant pipeline, that comprises an outdoor heat exchanger, a plurality of compressors, an outdoor expansion valve, and a four-way valve; and a dedicated outdoor air ventilation unit connected to the indoor unit and the outdoor unit via the refrigerant pipeline, that dehumidifies and ventilates outdoor air and supplies the outdoor air to the room, wherein the outdoor unit provides a refrigerant to both the dedicated outdoor air ventilation unit and the indoor unit by controlling the compressors depending on an operation mode of the dedicated outdoor air ventilation unit and the indoor unit. Accordingly, it is possible to run an air conditioner for cooling and heating and a dedicated outdoor air conditioner simultaneously by using a single outdoor unit. Moreover, the handling of sensible and latent heats can be controlled by a single outdoor unit, thereby minimizing facility costs and enhancing control reliability.

Heat pump systems with a gas bypass tank and that operate in both heating and cooling modes are disclosed. The systems include a first splitting valve that can route liquid refrigerant to either the indoor coil or the outdoor coil, depending on whether the heat pump system is in heating or cooling mode. An expansion valve in the system can lower the pressure of liquid refrigerant leaving a condenser, thereby creating a two-phase fluid comprising liquid refrigerant and vaporized refrigerant. The gas bypass tank can separate liquid refrigerant from vaporized refrigerant. The liquid refrigerant can be supplied to the evaporator of the system, while the vaporized refrigerant can be bypassed to a compressor. The first splitting valve can include a first plurality of switching paths that route the separated liquid refrigerant to either the outdoor coil or the indoor coil.

A refrigeration cycle apparatus includes a heat source unit configured to supply refrigerant, a first distribution unit and a second distribution unit respectively connected to the heat source unit, and a distribution pipe located between the heat source unit and the first distribution unit and the second distribution unit for distributing the refrigerant flowing from the heat source unit into the first distribution unit and the second distribution unit. Further, the first distribution unit and the second distribution unit individually include a heat exchanger configured to serve as a condenser. Further, if the refrigerant flowing through the distribution pipe is unevenly distributed into the first distribution unit and the second distribution unit, a degree of subcooling at an outlet of the heat exchanger of one of the first distribution unit and the second distribution unit of which the distributed refrigerant is of high quality is increased.

The present invention relates to an outdoor system for an air conditioner. In an air conditioner which comprises at least one outdoor system, the at least one outdoor system comprises: a compressor; an outdoor heat exchanger; a pair of two-stage compression lines extending to the outside of the outdoor system; a pair of connection lines extending to the outside of the outdoor system and communicating with an indoor unit; and multiple valves for opening/closing the pair of two-stage compression lines and the pair of connection lines when the outdoor system is operated in a one-stage heating mode or two-stage heating mode.

An air conditioner is disclosed. The air conditioner comprises: an indoor unit having an indoor heat exchanger installed therein; a first outdoor unit having a first outdoor heat exchanger and a first compressor installed therein; a second outdoor unit having a second outdoor heat exchanger and a second compressor installed therein; an auxiliary module which connects the indoor unit, the first outdoor unit, and the second outdoor unit; a first connection line by which the auxiliary module is connected to the first outdoor unit; a second connection line by which the auxiliary module is connected to the second outdoor unit; and a two-stage compression line by which the first outdoor unit is connected to the second outdoor unit.

A heating, ventilation, and air-conditioning (“HVAC”) system for use with a refrigerant. The HVAC system may include a compressor, an outdoor heat exchanger positioned downstream of the compressor, a first variable expansion device positioned downstream of the outdoor heat exchanger, an indoor heat exchanger positioned downstream of the first variable expansion device and upstream of the compressor and including a reheat portion and a main portion, a second variable expansion device positioned downstream of the reheat portion of the indoor heat exchanger and upstream of the main portion of the indoor heat exchanger, a first control valve operable to selectively control the flow of the refrigerant through the reheat portion of the indoor heat exchanger and the main portion of the indoor heat exchanger, and a control system programmed to selectively operate the HVAC system in one of a first cooling mode, a second cooling mode, and a dehumidification mode.