Abstract: A widthwise one half portion of a core section 5a is constituted by a first section 20 formed by stacking a plurality of first elements having first and second linear channels 34 and 35 inside them and fins, and a widthwise other half portion thereof is similarly constituted by a second section 21 formed by stacking a plurality of second elements respectively having U-shaped channels 46 inside them and fins. The number of times the refrigerant fed into a thicknesswise one half portion on an inlet tank 47 side of the first section 20 is turned back in an opposite direction concerning a longitudinal direction of the first linear channels 34 inside this thicknesswise one half portion is made more numerous than the number of times the refrigerant fed into a thicknesswise other half portion on an outlet tank 52 side of the first section 20 is turned back in the opposite direction concerning the longitudinal direction of the second linear channels 35 inside this thicknesswise other half portion.

Abstract: A widthwise one half portion of a core section 5a is constituted by a first section 20 formed by stacking a plurality of first elements having first and second linear channels 34 and 35 inside them and fins, and a widthwise other half portion thereof is similarly constituted by a second section 21 formed by stacking a plurality of second elements respectively having U-shaped channels 46 inside them and fins. The number of times the refrigerant fed into a thicknesswise one half portion on an inlet tank 47 side of the first section 20 is turned back in an opposite direction concerning a longitudinal direction of the first linear channels 34 inside this thicknesswise one half portion is made more numerous than the number of times the refrigerant fed into a thicknesswise other half portion on an outlet tank 52 side of the first section 20 is turned back in the opposite direction concerning the longitudinal direction of the second linear channels 35 inside this thicknesswise other half portion.

Abstract: A stack type evaporator for use in an automotive air conditioner comprises generally a first mass which includes first heat exchanging elements, each first heat exchanging element having mutually independent first and second passages; and a second mass which includes second heat exchanging elements, each second heat exchanging element having a generally U-shaped third passage which has first and second ends. The second mass is arranged beside the first mass in such a manner that the first and second heat exchanging elements are aligned on a common axis. An inlet tank passage connects to upper ends of the first passages. An upstream tank passage connects to lower ends of the first passages and the first ends of the third passages. A downstream tank passage connects to lower ends of the second passages and the second ends of the third passages. An outlet tank passage connects to upper ends of the second passages. An inlet pipe connects to the inlet tank passage.