A heat exchanger includes a plurality of hollow panels arranged in a stack with fins interspersed therebetween and each having a fluid passageway therein and an upper header and a lower header at opposite sides of the fluid passageway. An end plate is applied to at least one end of the stack and formed with an inlet opening and an outlet opening in nearby positions which communicate to a fluid circulation path defined in the stack by the fluid passageways and the upper and lower headers of the hollow panels. An inlet and outer manifold block is mounted on the end plate for fluidly communicating the inlet opening of the end plate to an inlet conduit and the outlet opening to an outlet conduit. An expansion valve is disposed within the inlet and outlet manifold block for controlling the quantity of an incoming flow of fluid directed from the inlet conduit toward the fluid circulation path in the stack via the manifold block and the inlet opening of the end plate in response to a temperature and a pressure of an outgoing flow of the fluid directed from the fluid circulation path toward the outlet conduit via the outlet opening of the end plate and the manifold block.