HEAT EXCHANGER AND AIR CONDITIONING APPARATUS

The present invention provides a heat exchanger and an air conditioning apparatus with which it is possible to minimize unevenly distributed flow of refrigerant and to minimize reverse current of the refrigerant flowing from the ascending space toward the descending space even in cases of use under conditions such that the circulation rate of the refrigerant varies. An outdoor heat exchanger 20 has a folding-back header 24 in which an ascending space 61b to which a plurality of flat perforated tubes 21b are connected and a descending space 62b are partitioned while communicating via an upper communication port 73 and a lower communication port 72. Within the folding-back header 24, the ascending space 61b and a first guide space 61a are partitioned while communicating vertically via an ascending opening 82a, 82b. When the heat exchanger is viewed from above after having been installed, the ascending opening 82a, 82b and the plurality of flat perforated tubes 21b have an area of overlap, but there is substantially no overlap between the ascending opening 82a, 82b and a space where the lower communication port 72 is extended in the direction in which the flat perforated tubes 21b extend.