Heat exchanger, and method for manufacturing heat exchanger

A method of fabricating a heat exchanger, the method comprising:

• building a semifinished heat exchanger including
• a first header having a first linear pipe section,
• a second header having a second linear pipe section in parallel to the first linear pipe section,
• heat transfer pipes arranged along the first linear pipe section and connecting the first linear pipe section and the second linear pipe section, and
• fins to transfer heat from the heat transfer pipes, the fins each being disposed between adjacent two of the heat transfer pipes, at least one fin of the fins having a weak portion, the weak portion of each of the at least one fin having a lower rigidity than other portions of the fin, the weak portion being more readily deformed than the other portions in response to a change in a distance between the adjacent two of the heat transfer pipes;
• and
• producing a heat exchanger including the first header having a first bent section and a first linear section extending from the first bent section and the second header having a second bent section bent in a same direction as the first bent section and opposed to the first bent section and a second linear section extending from the second bent section, the heat exchanger being produced by bending, in a same direction, the first linear pipe section of the first header included in the semifinished heat exchanger and the second linear pipe section of the second header included in the semifinished heat exchanger, wherein
• in the producing of the heat exchanger, the bending of the first linear pipe section of the first header and the second linear pipe section of the second header changes the distance between the adjacent two of the heat transfer pipes and deforms the weak portion,
• the heat transfer pipes include heat transfer pipes connecting the first linear section and the second linear section, and
• at least one of the heat transfer pipes connecting the first linear section and the second linear section is warped so as to be in a shape of a convex curve oriented toward the first bent section and the second bent section.