Abstract: An air-conditioning apparatus includes a fan configured to deliver air toward the outdoor heat exchanger, a power unit configured to supply electric power to the fan, a fan input detector configured to detect a physical value related to the electric power supplied to the fan, and a controller configured to control the four-way valve to switch between a first operation in which the outdoor heat exchanger functions as an evaporator and a second operation in which the outdoor heat exchanger functions as a condenser. The first operation is switched to the second operation when the physical value detected by the fan input detector is equal to or larger than a reference value. The controller adjusts the reference value so that the reference value when refrigerant flowing through the outdoor heat exchanger has a high temperature is smaller than the reference value when the refrigerant has a low temperature.

Abstract: Provided are rectangular plate-like fins 2 layered at intervals; and flat tubes 3 which are perpendicularly extended through the layered plate-like fins 2 and are provided on multiple levels along a longitudinal direction of the plate-like fins 2. The plate-like fins 2 are provided with at least one heat transfer promoting section 6 that is positioned in a region between adjacently-positioned flat tubes 3 and in which ridge sections 4 and valley sections 5 having ridgelines extending in the longitudinal direction of the plate-like fins 2 are arranged to alternate. En the heat transfer promoting section 6, at least one slit 7 allowing communication between a front and a back of the plate-like fin 2 is formed on a downwind side of the ridge sections 4.