The present invention relate to a spiral heat exchanger formed of at least two sheets extending along a spiral-shaped path around a common centre body and separated to form at least a first and a second spiral-shaped substantially parallel flow channels extending and enabling flow communication between a radially outer orifice and a radially inner orifice, characterized in that the centre body comprises a wall body with an first conduit at the inner surface of the wall body being in fluid connection to the first flow channel, and an second conduit formed at the outer surface of the wall body and being in fluid connection to the second flow channel.