A multi-type air conditioner is provided including an outdoor unit and a plurality of indoor units connected to the outdoor unit by a liquid pipe and a gas pipe. The plurality of indoor units includes a first indoor unit including first and second heat exchangers and first and second heat exchanger connecting pipes, and a second indoor unit. An indoor heat exchanger connecting pipe connects the first and second indoor units, and a liquid pipe connecting tube connects the first indoor unit and the liquid pipe. Opening amounts of a first indoor expansion valve, and first and second bypass expansion valves provided in the first indoor unit are opened selectively to operate the first heat exchanger as a condenser and the second heat exchanger as an evaporator to continuously drive a dehumidification mode while maintaining a room temperature within a predefined range.

Provided is a multi-type air conditioner, including: an outdoor unit comprising a liquid pipe through which liquid refrigerant flows and a gas pipe through which gas refrigerant flows; a plurality of indoor units comprising a first indoor unit and a second indoor unit each connected to the liquid and gas pipelines to circulate a refrigerant; a gas pipe connecting tube connecting the gas pipe and a plurality of indoor units so that a gas refrigerant flows therethrough; a first gas branch pipe connecting the first indoor unit and the gas pipe connecting tube so that a gas refrigerant flows therethrough; a second gas branch pipe connecting the second indoor unit and the gas pipe connecting tube so that a gas refrigerant flows therethrough; an indoor heat exchanger connecting pipe connecting the first indoor unit and the second indoor unit so that a liquid refrigerant flows therethrough; and a liquid pipe connecting tube connecting the first indoor unit and the liquid pipe so that a liquid refrigerant flows therethrough.

The first indoor unit may include: a first heat exchanger configured to perform heat exchange between indoor air and a refrigerant, a second heat exchanger configured to perform heat exchange between indoor air and a refrigerant and arranged in a stacked fashion with the first heat exchanger; a first indoor fan configured to blow air to the first heat exchanger and the second heat exchanger; a first liquid branch pipe connecting the indoor heat exchanger connecting pipe and the first indoor heat exchanger; a first heat exchanger connecting pipe connecting the first liquid branch pipe and the first heat exchanger of the first indoor heat exchanger; a second heat exchanger connecting pipe connecting the first liquid branch pipe and a second heat exchanger of the first indoor heat exchanger; and a first indoor expansion valve disposed at the second heat exchanger connecting pipe, wherein an opening amount of the first indoor expansion valve is adjusted in response to an input signal from the controller to selectively expand a flowing refrigerant.

The liquid pipe connecting tube may connect the first heat exchanger and a liquid pipe, and the first gas branch pipe may connect the second heat exchanger and the gas pipe.

Since the multi-type air conditioner according to the present disclosure can operate the first heat exchanger as a condenser and the second heat exchanger as an evaporator among the indoor heat exchangers, it is possible to continuously drive the dehumidification mode while maintaining the room temperature within a certain range There are advantages.

A heat pump system in a vehicle connected with a refrigerant line through which refrigerant flows for controlling cooling/heating of a cabin of the vehicle, including a compressor for compressing refrigerant, an outdoor heat exchanger for condensing high temperature and high pressure refrigerant compressed at the compressor, and an expansion valve for expanding the refrigerant compressed thus, may include an indoor heat exchanger arranged between the compressor and the expansion valve connected to one another with the refrigerant line, and having a partitioned inside to form individual flow passages, and a first valve connected to the compressor, the outdoor heat exchanger and the indoor heat exchanger with the refrigerant line for changing a direction of a refrigerant flow according to cooling, heating, and dehumidifying modes of the vehicle to control the refrigerant flow along the refrigerant line.