Abstract: A heat exchanger has: an inlet manifold having an inlet port; and an outlet manifold having an outlet port. A first gas flowpath passes from the inlet port to the outlet port. A plurality of plate banks are positioned end-to-end, each plate bank having a plurality of conduits with interiors along respective branches of the first gas flowpath, a second gas flowpath extending across exteriors of the plurality of conduits. One or more docks couple adjacent ends of the plurality of plate banks.