Abstract: A heat exchanger core includes a first fin passage. A first frame surrounds a perimeter of the first fin passage. The first frame includes a plurality of bars configured to be removable from the first frame.

Abstract: In some examples, a plate fin heat exchanger including a cold passage defined by a cold frame; a hot passage defined by a hot frame; a tube sheet between the cold passage and the hot passage; a top side plate; and a bottom side plate, wherein the cold frame includes a first bar and a second bar attached at a corner of the heat exchanger, wherein at least a portion of the first bar is configured to be removed from the cold frame, wherein the hot frame includes a third bar and a fourth bar attached at the corner of the heat exchanger, wherein at least a portion of the third bar is configured to be removed from the hot frame, and wherein the corner of the heat exchanger defined by at least one of the hot frame or the cold frame has a non-square shape.

Abstract: A heat exchanger core includes a first fin passage. A first frame surrounds a perimeter of the first fin passage. The first frame includes a plurality of bars configured to be removable from the first frame.