A heat exchanger

A heat exchanger of the welded plate type for heat transfer between air and liquid, said heat exchanger comprising:

• a plurality of plates with each with an internal volume inside a peripheral flange having a flange thickness, and which are in parallel fluid communication with an inlet and an outlet;
• said plates being mounted in a frame with a mutual predetermined distance, such that air can flow between the plates, and wherein the plates are mounted between at least two plate holding frame members on opposite sides of said plates, wherein said plate holding frame members are provided with an exterior edge and with a plurality of slits in a comb-like shape extending from said exterior edge;
• the plurality of slits include first type slits and second type of slits provided in an alternating configuration, wherein the first type slits are formed with a narrow entry passage section having a width corresponding to the flange thickness and a widened opening section there behind, and wherein the first type slits are adapted to receiving the peripheral flanges of the plates in the narrow passage section;
• and wherein the second type slits are substantially straight and left vacant.