Abstract: The upstream side ends of fins (16) along the ventilating direction project out relative to the upstream side ends along the ventilating direction of tubes (14) without being allowed to project out beyond the end faces of tanks (2) and (3) along the ventilating direction so as to set the tubes (14) at positions recessed toward the downstream side along the ventilating direction relative to the fins (16), and the downstream side ends of the fins (16) along the ventilating direction are recessed further toward the upstream side along the ventilating direction relative to the downstream side ends of tubes (15) along the ventilating direction.

Abstract: A heat exchanger that achieves a reduction in the dimensions of the header pipes, a sufficient level of strength against pressure and a structure that allows the caps to be washed thoroughly during the washing process is provided At each of the caps closing off the two ends of the cylindrical portion constituting a header pipe, a circular groove at which the circumferential edge at an end of the cylindrical portion is fitted over the entire circumference is formed to completely fit the cylindrical portion inside the cap so that the dimensions of the header pipe along the axial direction are reduced. In addition, by forming a thick portion at a closing portion, the pressure withstanding capability of the cap is improved. The cap also has a projected portion at its outer flat surface.