Drying by dehumidification refers to a process in which moisture is removed from a solid using heat as the energy input. In many agricultural countries, large quantities of food products are dried to improve shelf life, reduce packaging costs, lower shipping weights, enhance appearance, retain original flavour and maintain nutritional value (Sokhansanj & Jayas, 1987). However, from an engineering point of view, it is obvious that drying is an energy-intensive process because latent heat has to be supplied to the material to evaporate the moisture. Conventional dryers require large quantities of energy for heating and removing water, and a relatively high temperature moist air is allowed to leave from the open circuit dryer