This paper describes an experimental investigation of the performance characteristics of a novel, cross-corrugated, polymer film, compact, heat-exchanger (PFCHE) made from poly ether ether ketone (PEEK). The aim is to develop Jh and f correlations over a range of Reynolds numbers under laminar conditions to be used in alternative heat-exchanger designs for potential applications in the fuel-cell industry. The incentive for adopting these designs is the huge weight, energy and cost savings involved. Design correlations for square units are key tools in obtaining alternative designs for applications that are presently monopolized by metallic heat-exchangers. The design correlations are establised and then used to perform case studies in selected applications in the fuel-cell industry to suit the fluids and the configuration. (C) 2004 Elsevier B.V. All rights reserved.