Heat exchanger is a device used to efficiently transfer heat from one fluid to another. The fluids may be separated to avoid direct contact or mixing. Two fluids, of different starting temperatures, flow through the heat exchanger. One flows through the tubes (the tube side) and the other flows outside the tubes but inside the shell (the shell side). Heat is transferred from one fluid to the other through the tube walls, either from tube side to shell side or vice versa. The fluids can be either liquids or gases on either the shell or the tube side. In order to transfer heat efficiently, a large heat transfer area should be used, leading to the use of many tubes. In this way, waste heat can be put to use. This is an efficient way to conserve energy. This Database was designed to perform Heat Transfer Equipment Cost Estimates, based on generic cost curves for several equipment families types generated using benchmarking techniques. The benchmarked curves give Purchased Equipment Cost as a function of a capacity variable or combination of variables. The cost curves and other information contained in this application can be used to develop the overall process plant capital cost.