The aim of the present work is to analyse a novel solar air heater configured with U-shaped longitudinal fins. The application of the proposed air heater for freshwater production and ag-riculture drying has also been analysed for the coastal area of India. The results are motivating for use of the proposed air heater for household requirements and smallscale industrial pur-poses to improve the earning in coastal regions. The mathematical model for time-dependent behaviour of the proposed air heater has been prepared by considering the energy balance of air heater components and solved to get the outlet temperature of the air from air heater. The results proved that the heater is suitable for the desalination and drying of many agricultural products. The effect of operating parameters has also been analysed to find suitable values for freshwater production. Optimum air mass flow rate of 160 kg/hr in air heater has been found whereas higher water temperature in the storage tank and lower temperature of cooling water in dehumidifier found suitable for higher yield of freshwater. In the drying process, significant improvement has been observed compared to direct solar drying and conventional air heater with 12 hours drying time for banana slices and 10 hours for garlic was found.