Heat exchanger

An air-cooled and ventilated heat exchanger, comprising:

• a fin having a plate-shaped part and a plurality of protruding parts, the plate-shaped part being positioned so that a plate-thickness direction intersects an air-flow direction generated by ventilation, and the protruding parts protruding from the plate-shaped part in the plate-thickness direction;
• and
• a plurality of heat-transfer tubes inserted into the fin so as to intersect the air-flow direction,
• the plurality of the protruding parts having a plurality of first protruding parts and a plurality of second protruding parts, with
• an inclination angle of each of the first protruding parts with respect to the plate-shaped part being a first angle,
• an inclination angle of each of the second protruding parts with respect to the plate-shaped part being a second angle,
• the second protruding parts being placed adjacent to the first protruding parts in an individually alternating manner such that at least one first protruding part is disposed adjacent second protruding parts on opposite sides thereof relative to the airflow direction and at least one second protruding part is disposed adjacent first protruding parts on opposite sides thereof relative to the airflow direction,
• an inclination direction of the first protruding parts and an inclination direction of the second protruding parts are the same on the same surface of the plate-shaped part,
• the second angle being larger than the first angle, and
• spacing between free ends of adjacent alternating first and second protruding parts being approximately equal.