In this paper, a study on open sun and green house drying has been performed to evaluate the convective heat and mass transfer coefficients as a function of climatic parameters. The hourly data for the rate of moisture removal, crop temperature, relative humidity inside greenhouse and outside greenhouse and ambient air temperature for complete drying have been recorded. The experiments were done in the premises of Allahabad Agricultural Institute-Deemed University, after the crop-harvesting season from February 2006 to April 2006. Using these data, the value of convective heat and mass transfer in Open Sun Drying (OSD) and Green House Drying (GHD) under natural and forced convection mode have been calculated. On the basis of this study, it is inferred that the value of convective heat and mass transfer is more in OSD than in the Green House Drying (GHD) under natural convection mode. However, its value increases in forced mode of GHD when compared with natural mode in the initial stage of drying.
Keywords: greenhouse drying, greenhouses, natural convection, forced convection, heat transfer, mass transfer, moisture removal, crop temperature, relative humidity, ambient air temperature, open sun drying, crop drying