The main purpose of a heat exchanger system is to transfer heat from a hot fluid to a cooler fluid, so temperature control of outlet fluid is of prime importance. In this work, different controllers such as PID controller, feedback plus feed-forward controller and a ratio controller are developed to control the outlet temperature of a shell and tube heat exchanger. The developed ratio controller has improvement in the overshoot and settling time over the classical controller and feed-forward plus feedback controller. Control accuracy is also good as steady state error becomes zero.