A heat exchanger for exchanging heat between a first medium and a second medium has a body comprising a pair of header plates, a pair of distribution plates, and a pair of case body lateral panels. Input and output header plates have a plurality of orifices, with a flow path assembly extending between each input header plate orifice and the corresponding output header plate orifice. Each flow path assembly includes at least one chamber assembly, having a corresponding medium directing component, disposed between a pair of tubular segments. Input and output distribution plates have a plurality of orifices. A first medium inlet side tank engages with the input header, a first medium output side tank engages with the output header plate, a second medium inlet side tank engages with the input distribution plate, and a second medium output side tank engages with the output distribution plate.