A heat pump system is provided, comprising: a cooling and heating coil having first and second refrigerant ports; a reheat coil having third and fourth refrigerant ports; first and second refrigerant pipes connected to the first and second refrigerant ports, respectively; a first solenoid valve between the third refrigerant port and the second refrigerant pipe; a second solenoid valve between the fourth refrigerant port and the second refrigerant line; an expansion valve between the fourth refrigeration port and the second refrigerant port; a first check valve between the fourth refrigerant port and the expansion valve; a second check valve between the expansion valve and a condensing circuit; a third check valve between the first check valve and the expansion valve; a fan circuit for blowing air across the cooling and heating coil and the reheat coil in order; and a controller for controlling the heat pump system.

An air conditioner including an outdoor unit, an air conditioning indoor unit, a showcase indoor unit, and a combination unit. The combination unit includes a first gas control unit connected to the air conditioning indoor unit gas pipe, a second gas control unit connected to the showcase indoor unit gas pipe, a first pipe which connects the outdoor unit liquid pipe and the indoor unit liquid pipe, and a second pipe which connects the first pipe and the second gas control unit. The first gas control unit and the second gas control unit are converged to be connected to the outdoor unit gas pipe, so that the air conditioning indoor unit and the showcase indoor unit can use a single outdoor unit, and heat emitted from the air conditioning indoor unit to a room during a heating operation is used as condensation heat of the showcase indoor unit.

An air conditioner may include a continuous refrigeration apparatus including a first gas control unit connected to a first indoor heat exchanger, a second gas control unit connected to a second indoor heat exchanger, a first pipe connecting a liquid pipe of an outdoor unit and a liquid of an indoor unit, and a second pipe branched from the first pipe and connected to the first and second gas control units. The first gas control unit may include a first-first flow path connecting the first gas control unit to the second pipe; a first-second flow path connected to the first-first flow path, and through which refrigerant discharged from the first indoor heat exchanger flows during a refrigeration operation; and a first-third flow path connected in parallel with the first-second flow path, and guiding refrigerant from the compressor to the first indoor heat exchanger during a defrosting operation.

An air conditioner including: an outdoor unit, an air conditioning indoor unit, a showcase indoor unit, and a combination unit, wherein the combination unit includes a first gas control unit which is connected to the air conditioning indoor unit gas pipe, a second gas control unit which is connected to the showcase indoor unit gas pipe, a first pipe which connects the outdoor unit liquid pipe and the indoor unit liquid pipe, and a second pipe which connects the first pipe and the second gas control unit, and the first gas control unit and the second gas control unit are converged to be connected to the outdoor unit gas pipe, so that the air conditioning indoor unit for cooling and heating operation and the showcase indoor unit for refrigeration operation can use a single outdoor unit, and the heat emitted from the air conditioning indoor unit to the room during the heating operation of the air conditioning indoor unit is used as the condensation heat of the showcase indoor unit so as to zero the energy use for heating.

An air conditioner including: a continuous refrigeration apparatus comprising a first gas control unit connected to a first indoor heat exchanger of the plurality of indoor heat exchangers, a second gas control unit connected to a second indoor heat exchanger of the plurality of indoor heat exchangers, a first pipe connecting a liquid pipe of the outdoor unit and a liquid of the indoor unit, and a second pipe which is branched from the first pipe and connected to the first gas control unit and the second gas control unit, wherein the first gas control unit comprises: a first-first flow path connecting the first gas control unit to the second pipe; a first-second flow path which is connected to the first-first flow path, and through which the refrigerant discharged from the first indoor heat exchanger flows during a refrigeration operation of the first indoor heat exchanger; and a first-third flow path which is connected in parallel with the first-second flow path, and guides the refrigerant discharged from the compressor to the first indoor heat exchanger during a defrosting operation of the first indoor heat exchanger, and connects a gas pipe of the outdoor unit and the first indoor heat exchanger.

A heat-pump-type vehicular air-conditioning that includes a cooling refrigerant circuit. The circuit has a base for connecting an onboard condenser provided on the downstream side of an onboard evaporator inside an HVAC unit. The circuit includes a second decompression unit between the outlet side of a receiver and one end side of a vehicle-mounted external heat exchanger. Also included is a second circuit having a solenoid valve opened during heating between the other end side of the vehicle-mounted external heat exchanger and the intake circuit of an electric compressor. The vehicular air-conditioning system being provided with a heating refrigerant circuit in which the electric compressor, a switching unit, the onboard condenser, the receiver, the first circuit, the vehicle-mounted external heat exchanger, and the second circuit are connected in the stated order.

The present disclosure relates to a HVAC system operable to use a refrigerant in a refrigerant circuit to heat or cool an indoor space and includes a defrost circuit connected to the refrigerant circuit. The defrost circuit includes a first three-way valve, a defrost line, a defrost passage in an outdoor heat exchanger, and a defrost return line. When the HVAC system is in a defrost mode, a four-way valve is operable to direct the refrigerant flow in a second direction through the outdoor heat exchanger. The first three-way valve is operable to divert some or all of the refrigerant from the refrigerant circuit and through the defrost circuit to defrost the outdoor heat exchanger. The defrost return line returns the diverted refrigerant to the refrigerant circuit upstream of an expansion device and downstream of the indoor heat exchange with respect to the second direction.