Research Article published by Tanzania Journal of Engineering and Technology (TJET) Vol.5 ( No.1), June 2014Fruits drying had become a broader technology in fruits and vegetables value addition. The technology is reported to be a promising way of dying without incurring higher cost but its adaptation has not been feasible in rural areas. Solar dryers have been developed but its poor performance limits its applicability. In this study, several techniques for modifications of traditional solar collector were addressed. It was observed that, varying collector designs in different techniques, a range of collector performances can be employing double duct counter flow, compared to conventional collectors. Likewise performance difference between conventional collectors and studied models were found to be 8%, 7.2%, 6.1% and 5.2% for model parked with charcoal 5 mm wire mesh, 4mm glass thickness and 8 baffles respectively. This study shows that, double duct counter flow system is the best option for improving the performance of the collectors, followed by charcoal and wire mesh. On the hand, using 4 mm glass thickness gave improved performance, however, it is recommended for collector size not exceeding 2 m in length.