Shell-and-Tube Heat Exchanger - is a user friendly program which for a given heat exchanger initial conditions and geometry predicts outlet temperatures of both shell-side and tube-side fluids, heat exchanged, pressure drop on the tube sides and fluid velocity in the inlet/outlet nozzles. For a given input and output conditions the program can estimate preliminary heat exchanger design parameters. Program assumes: heat exchange between counterflow fluids shell insulation heat transfer with ambient air. shell side fluid heating is possible evaporation and condensation are not considered