A review on solar tunnel greenhouse drying system

This paper mainly deals with review of research and development work on solar tunnel and greenhouse type dryers operating in natural and forced convection mode by different researchers. The comprehensive explanation, basics and earlier work performed on solar tunnel greenhouse type dryers has been presented briefly. A technical and economical assessment shows that solar tunnel and greenhouse dryers appear the most gorgeous option for use in rural areas. Trials on solar tunnel and greenhouse type dryer show not only massive fuel savings but also great worth addition due to improved quality of dried product in terms of color, aroma and taste. However application of such dryers has not picked up due to higher capital investment, long payback period and lack of confidence in the technology. Nevertheless incessant research and development work should be carried out to overcome these factors. It is hoped that this review work may be valuable and appropriate for further development work.