FIN TYPE HEAT EXCHANGER

PROBLEM TO BE SOLVED: To provide a fin type heat exchanger capable of improving a heat transfer performance by a method wherein some slits are formed symmetrically around a line connecting the centers of pipe holes forming rows in such a way that pipes and fins are contacted uniformly when the pipes are inserted into the pipe holes to expand a diameter of each of the pipes. SOLUTION: A fin type heat exchanger is comprised of many fins 2 arranged in parallel to each other to cause air stream to pass therein; at least two rows of pipes 3 passing through each of fins 2 in perpendicular to it and having work fluid flowed therein; and a group of slits formed at each of the fins 2, wherein the group of slits are protruded at both front and rear sides of the fins 2 and formed symmetrically around a line connecting the centers of the pipes 3 in rows and the number of rows of slits formed between the pipes 3 in rows is reduced as they approach from an air stream outlet to an air stream inlet. With such an arrangement as above, a heat exchanging performance between the fins 2 and the pipes 3 is improved.