The AHED program is a powerful design tool for the calculation of one of the most used items of process equipment: shell and tube and heat exchangers (STHE’s). STHE’s are used in widespread process industries including Chemical, Oil & Gas, Wastewater, Food, Pharmaceutical & Automotive. The design of STHE’s is fundamental for a process installation to work to its optimum. It is vital that heat exchangers meet the desired duty within the available space and economical constraints (capex and opex). Traditionally designing the correct STHE has meant the need for investment in costly software solutions, which are not available to everybody. AHED was designed to overcome this without compromising the calculation precision needed for modern industry.