Basic heat transfer results for natural convection in an array of vertical in-line plate segments were obtained by numerical finite-difference solutions and are tabulated along with previously computed results for staggered and continuous-plate arrays. These results were employed as the basis of three performance comparisons Involving alt three types of arrays, with the continuous-plate array serving as a baseline case. In the first of these comparisons, it was found that the discrete-plate arrays can enhance the heat transfer rate by as much as 80-90% for fixed values of the wall-to-ambient temperature difference and heat transfer surface area. Furthermore, the use of discrete plates affords the possibility of reducing the wall-to-bulk temperature differences by as much as 35-40% at a fixed heat load and surface area. Reductions in the height of the array of up to 50% can also be achieved for conditions of fixed heat load and fixed wall-to-bulk temperature difference. The attainment of enhanced heat transfer characteristics by the use of discrete plates depends on certain key parameters, which are identified in the paper. In general, the degree of enhancement is not very sensitive either to the arrangement of the discrete plates (in-line or staggered) or to the number of plates that bound a subchannel.