A mathematical model has been developed to solve the heat and mass transfer equations for convective drying of tropical fruits. The model takes into account shrinkage of material and moisture content and shrinkage dependant effective diffusivity. Heat and mass transfer equations for the dryer, termed as equipment model, have also been developed to determine the changes of drying potential of the drying medium during drying. The material model is capable of predicting the instantaneous temperature and moisture distribution inside the material. The equipment model, on the other hand, describes the transfer process in the tunnel dryer and predicts the instantaneous temperature and humidity ratio of air at any location of the tunnel. Thus, the model is capable of predicting the dynamic behaviour of the dryer. The predicted results were compared with experimental data for the drying of banana slices dried in a solar dryer. Experimental results validated the model developed. (c) 2005 Elsevier Ltd. All rights reserved.