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.

There are provided an inverter connected to n (n being as integer not less than 2) motors each including a rotor having a permanent magnet and capable of driving the n motors, and a connection switching device to switch a connection state of at least one motor of the n motors and the inverter between connection and disconnection. While the n motors are connected to the inverter and driven by the inverter, when an abnormality is detected in the at least one motor, the connection switching device switches the connection state to the disconnection and the inverter drives the n motors except the at least one motor.

A geothermal heat pump system which may be installed in a building and operated as an air source heat pump system using an exterior heat exchanger as a heat source or heat source/sink, but which includes geothermal components including a geothermal heat exchanger. The geothermal heat exchanger may be isolated in initial operation of the system for heating and cooling but may be connected to a geothermal heat source/sink following initial installation of the heat pump system for use in heating and cooling as a heat source and a heat source/sink, respectively. In this manner, the heat pump system may be initially operated as a standard air source heat pump and optionally later converted into a geothermal heat pump system.

A system comprising a compressor, a first valve coupled to the compressor and to a first coil, a first expansion valve coupled to the first coil, and a second expansion valve. The second expansion valve coupled to a second coil. A second valve is coupled to the second coil and the compressor. A third valve is coupled to the compressor and a third coil. In response to receiving a heating demand that is below a threshold heating demand, a controller induces an artificial heating demand.

An air conditioner including a compressor, an outdoor heat exchanger, an expansion valve, an indoor heat exchanger, a first fan, a second fan, and a cooling/heating conversion device. The compressor is configured to compress a refrigerant and including a first compressor and a second compressor. The outdoor heat exchanger is configured to exchange heat of the refrigerant with outdoor air, and includes a first and second heat exchanger. The expansion valve is configured to expand a refrigerant. The indoor heat exchanger is configured to exchange heat of the refrigerant with indoor air. The first fan and the second fan correspond to the first heat exchanger and the second heat exchanger, respectively. The cooling/heating conversion device during a during a heating operation is connected in parallel to the first and second heat exchangers, and during a during a cooling operation is connected in series to the first and second heat exchangers.

The refrigeration cycle apparatus includes a refrigerant circuit, a controller to control the refrigerant circuit, a bypass flow path, and a flow control valve. The bypass flow path communicates between the discharge side of the compressor and the first outdoor heat exchanger or between the discharge side of the compressor and the second outdoor heat exchanger. The flow control valve is provided to the bypass flow path. The refrigerant circuit is configured to be able to perform a heating defrosting simultaneous operation. The heating defrosting simultaneous operation is an operation of supplying part of the refrigerant discharged from the compressor to one of the first outdoor heat exchanger and the second outdoor heat exchanger via the bypass flow path, causing the other of the first outdoor heat exchanger and the second outdoor heat exchanger to serve as an evaporator, and causing the indoor heat exchanger to serve as a condenser.

A distributor includes an upstream flow path and a downstream flow path. The downstream flow path has a branch portion and a bent portion. The branch portion has a first connecting portion connected to the upstream flow path to branch a refrigerant flow from the first connecting portion in a second direction intersecting a first direction. The bent portion has a second connecting portion connected to the branch portion and is located downstream of the branch portion in the refrigerant flow. The second connecting portion of the bent portion is located downstream of the first connecting portion of the branch portion in the refrigerant flow.

A low ambient cooling system for a variable refrigerant flow heat pump includes an outdoor air conditioning unit and an indoor air conditioning unit. The outdoor air conditioning unit includes an outdoor heat exchanger with one or more valves that selectively control refrigerant flow through different sections of condenser coils during a low ambient cooling mode. During the low ambient cooling mode, the condenser coils of the outdoor heat exchanger include an active coil section through which refrigerant flows and an inactive coil section that is closed. An outdoor-coil restrictor plate with holes is attached to the active condenser coil in the outdoor air conditioning unit. The outdoor-coil restrictor plate restricts excessive heat release from the active coil section of the condenser coils in the outdoor heat exchanger during the low ambient cooling mode.

An HVAC system includes an outdoor heat exchanger. A first indoor heat exchanger is fluidly coupled to the outdoor heat exchanger and disposed in a first zone. A second indoor heat exchanger is fluidly coupled to the outdoor heat exchanger and disposed in a second zone. A compressor is fluidly coupled to the outdoor heat exchanger, the first indoor heat exchanger, and the second indoor heat exchanger. A first circulation fan is positioned to circulate air around the first indoor heat exchanger and a second circulation fan is positioned to circulate air around the second indoor heat exchanger. A first zone controller is electrically coupled to the first indoor heat exchanger. The first zone controller is configured to measure a temperature in the first zone, compare the measured temperature to a setpoint temperature of the first zone, and responsive to a difference between the measured temperature and the setpoint temperature, adjust a speed of the first circulation fan independent of the speed of the second circulation fan.

A heat pump system includes a compressor, a four-way valve, an outdoor heat exchanger, a throttling device and an indoor heat exchanger connected in sequence to form a refrigerant main circuit. The outdoor heat exchanger includes at least one double-rowed heat exchanger. The heat pump system has a cooling mode and a heating mode, and further includes a switching unit. The switching unit is connected in the refrigerant main circuit, and switches a flow direction of a refrigerant, such that the refrigerant flows into the outdoor heat exchanger through one of the first heat exchanger and the second heat exchanger, and flows out of the outdoor heat exchanger through the other one of the first heat exchanger and the second heat exchanger both in the cooling mode and in the heating mode.