Plate fin heat exchangers and methods for manufacturing same

A plate fin heat exchanger, the heat exchanger comprising:

• a lower compression end plate having a first heat exchanger fluid inlet connected thereto;
• an upper compression end plate, a first heat exchanger fluid outlet connected thereto;
• and
• two stacked heat exchanger subassemblies located between the lower and upper compression end plates, each subassembly having:
• i) first, second and third plates in intimate contact with each other, the first plate being sandwiched between the second and third plates, each of the plates having a first at least one fluid opening and a second at least one fluid opening located at the ends of each plate, the first plate having at least one elongate fluid channel extending between the first and second fluid openings;
• ii) a first fluid passageway for a first heat exchanger fluid extending through the first and second fluid openings in each plate and along the elongate channel in the first plate;
• iii) a plurality of interconnected fins having first and second heat transfer surfaces, the first heat transfer surface of each fin being in intimate contact with the second plate so as to create a plurality of second fluid passageways for the second heat exchanger fluid to flow therealong;
• and
• between the two subassemblies, at least one manifold spacer body is located at each end of the interconnected fins, the manifold spacer body being located to permit a two-pass heat exchanger configuration.