This paper presents a periodical analysis of multi-tray crop drying attached to an inclined multi-pass solar air heater with in-built thermal storage. The performance of multi-tray drying integrated with a solar air heater was evaluated for drying of the paddy crop. A parametric study was done for a day of the month of October for the climatic conditions of Delhi (India), The effect of change in the tilt angle, length and breadth of a collector and mass flow rate on the temperature of crop was studied, The thin layer drying equation has been used to study the drying rate and hourly reduction in moisture content in the different trays, It has been observed that the crop moisture content decreases with the drying time of the day. Different drying rate has been observed in different drying trays due to the variation in crop temperatures. The thermal efficiency of the drying increases with increase in mass of the crop. (c) 2004 Elsevier Ltd. All rights reserved.