Heat exchanger

A heat exchanger comprising:

• a heat transfer tube extending in a first direction;
• and
• a plurality of fins stacked in the first direction, each of the plurality of the fins including
• a body portion extending in a second direction that intersects the first direction, and
• a collar portion that allows the heat transfer tube to pass therethrough, the collar portion having
• a first portion extending from the body portion in the first direction,
• a second portion extending from the first portion toward the heat transfer tube, and
• a third portion extending in the first direction from the second portion along the heat transfer tube,
• the second portion of a first fin of the plurality of fins being in contact with a distal end portion of the collar portion of a second fin of the plurality of fins disposed adjacent to the first fin, and
• each of the plurality of fins being provided with a drain rib, and the drain rib extending from a convex space formed by the first portion and the second portion of the first fin and a distal end of the collar portion of the second fin.