Abstract: A heat exchanger device (13) comprising a tubular body (2) having an inlet opening (3) and an outlet opening (4) and defining within itself a first pathway (5) for a first liquid in a first prevalent direction of advance (6) from the inlet opening (3) to the outlet opening (4); a first connecting terminal (7) having at least a first inlet (8) for the first liquid and being sealedly couplable to the inlet opening (3) of the tubular body (2) and further couplable, at the first inlet (8) for the first liquid, to a first outlet pipe (9) for the first liquid; a second connecting terminal (10) having at least a first outlet (11) for the first liquid and being sealedly couplable to the outlet of the tubular body (2) and further couplable, at the first outlet (11) for the first liquid, to a second outlet pipe (12) for the first liquid; and an exchanger element (13) having an inlet (14) and an outlet (15) for a second liquid and defining within itself a second pathway (16) for the second liquid, the exchanger element