Comparison of Test Results for Flat-Plate, Transpired Flat-Plate, Corrugated, and Transpired Corrugated Solar Air Heaters

Five selective-black-metal-plate experimental air heaters with and without transpiration were designed, fabricated, and tested to compare their technical merits. All were 61 cm × 61 cm (2ft × 2ft), double-glazed with low-iron glass, and those with transpiration contained an additional Teflon film to form a plenum above the absorber plate. The configurations were (i) a reference collector with flow on back only, (iia) a transpired slotted plate, (iib) a transpired micro-perforated plate, (iii) a corrugated plate with flow on back, and (iv) a transpired slotted corrugated plate. The results show the magnitude of technical improvement that can be obtained through the slotting, perforating, and corrugating strategems.