Analyzing the effect of flooring material type on the performance of an active greenhouse dryer

Abstract

In this work, the impact of flooring (bottom) material selection on the performance of an active greenhouse dryer (AGD) has been empirically surveyed. In this regard, four AGD configurations with different flooring materials including soil, gravel, sheet metal with conventional black paint and sheet metal with iron (Fe) nano-enhanced black paint have been designed, manufactured, and experimented at same fixed air flow rate. According to experimentally obtained findings, utilizing nano-enhanced black-painted sheet metal in the AGD instead of soil has a potential to almost double the average air temperature difference. Also, using sheet metal with nano-enhanced black paint reduced the drying periods as 41.17 %, 33.33 % and 20 %, respectively in comparison to the configurations that used soil, gravel and sheet metal with conventional matt black paint as bottom material. Average exergetic efficiencies for the tested configurations were obtained between the range of 3.22–11.14 %. Also, using sheet metal with Fe nano-enhanced absorber coating as a bottom material in the system reduced the carbon footprint as 32.66 % (from 1.50 to 1.01 kgCO2eq) in comparison to the system with soil bottom.