Interior heat exchanger

An interior heat exchanger comprising a pair of heat exchangers, each having a tube group including a plurality of refrigerant flow tubes extending in a vertical direction and arranged to be parallel, an upper end portion and a lower end portion of the tube group being connected to communicate with an upper header and a lower header, the headers extending in a horizontal direction, wherein the first heat exchanger disposed on an upstream side in a refrigerant flow direction is disposed on a downstream side in a direction of air blown to a cabin, and the second heat exchanger disposed on a downstream side in the refrigerant flow direction is disposed on an upstream side in the air blowing direction, wherein the header of the first heat exchanger and the header of the second heat exchanger, adjacent to the header of the first heat exchanger, are connected to communicate with each other, wherein the interior heat exchanger is configured as a counter-flow type so that the interior heat exchanger functions as a condenser capable of performing a supercooling operation at a temperature exceeding 35° C. during heating, whereas the interior heat exchanger allows a refrigerant in a gas state to pass through during cooling,

• wherein an inner portion of at least one of the headers of the first heat exchanger and the second heat exchanger is divided into horizontally arranged spaces, the tube group of each heat exchanger is defined to be heat exchange regions so that the refrigerant flow direction is inverted between the adjacent tube groups, and in the second heat exchanger, a heat exchange region on the most downstream side in the refrigerant flow direction is set to be larger than a heat exchange region on an upstream side in the refrigerant flow direction,
• wherein in the first heat exchanger, a refrigerant channel area of each heat exchange region is set to be larger than a sectional area of a refrigerant introduction pipe connected to the first heat exchanger.