Innovative Low-Cost Naturally Ventilated Maize Seed Storage System

Abstract

A 22-m3 residential room was converted to a seed storage facility by retrofitting a solar collector on the roof. Three different chimney sizes of diameter and height of 200 mm x 3.6 m, 200 mm x 4.8 m, 300 mm x 3.6 m and 300 mm x 4.8 m were investigated to determine the best size of the chimney to be used for ventilation in a storage facility. The parameters measured were the air velocity in the chimney duct, as well as the air temperature and relative humidity at the inlet, centre and outlet of the storage facility. The diameter of the chimney had a significant effect (P<0.05) on the ventilation rate achieved in the storage facility. Significant differences were found between the different chimney diameters and heights (P 0.05). The 300 mm diameter chimneys were able to extract hot air from the roof solar collector; however, the 200 mm diameter failed. The modified naturally-ventilated seed storage room was able to reduce the relative humidity from 69.7% to a safe relative humidity of 37.9%, while at the same time the temperature increased from 23.3℃ to 35℃ in the 300 mm x 4.8 m chimney.