The main objective in this article is to find new exchanger area for the previously found optimum configurations. That is, goal of this article is to optimize a network with specific configuration by using ACO(R). In the present work, the networks with stream splits will be optimized by removing splits. Stream splitting can lead to more energy recovery using powerful algorithms in appropriate search space. Removing splits reduces complexities and leads to advantages like more real simulations, more adaptable networks to consider pressure drop and flow regime and near real cost estimations. Also, in the present work, the optimal Delta T-min is evaluated implicitly in the solution process. To show the power of the ACO(R) algorithm, seven case studies of different sizes are presented and the results show that more economic networks, than those generated by other methods, do exist and have not been ever explored. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.