An analysis is made to quantify, the effect of flow maldistribution on the performance of a laminar; counterflow, high-effectiveness heat exchanger. An investigation of the ability of thermally connected fins in one passage (screen mesh) to correct the uneven heat transfer distribution from the maldistributed mass flow in the other passage is made. A heat transfer model is developed for both passages. A parametric study presents the effect of adding thermal paths to correct the uneven heat transfer A redefined fin efficiency is proposed to incorporate the fins＇ ability to correct uneven hear transfer Data are compared to the model.