The 0.6×0.6 m2 cabinet was constructed primarily of plywood to house five trays made of wooden frames encompassing expanded steel grating. The trays were designed to be removable as shown in figure 2 for easier cleaning, loading, and rotation which was particularly important in establishing a continuous mode of operation. The front end of each tray was designed with a wider frame
to assist in the distribution of incoming heated air.A single, hinged door was installed on the rear of the cabinet to provide access to the product trays and the thermal rock storage bed located at the base of the drying chamber. The thermal storage component was sized according to the lower volume limit of 0.15 m3 as recommended by Adebayo and Irtwange (2009). The thermal storage area was filled with black lava rock pebbles. All interior and exterior surfaces of the solar collector, drying cabinet, trays, chimney, and thermal rock bed were painted matte black to help maintain elevated temperatures within the dryer by enhancing heat absorption. Although insulation is expected to improve heat retention within the cabinet, it was desired to keep the cost of materials to a minimum. Thus, no insulation was used in the cabinet during field trials.