Experimental Data for GTC in Natural Convection Mode
The data presented were for the experimental study of a glazed transpired solar collector (GTC) in natural convection mode. Transpired solar collectors used as air heaters require adequate pressure difference across the collector for practical application. In most cases an electric fan of suitable power is deployed to achieve the required pressure difference. This is the forced convection application. In a natural mode of application a chimney of appropriate height is required and buoyancy forces in the collector and chimney produce the required pressure difference across the collector. An experimental rig was set up in the field and data was collected for a period of 6 months. Data represents average values of variables. The variables included chimney height, ambient air temperature, collector air temperature, absorber temperature, collector air outlet velocity, solar radiation and absorber hole pitch to hole diameter ratio (P/D). Five absorber plates having hole diameters of 1.0mm, 1.5mm, 2.0mm, 2.5mm and 3.0mm were used and the chimney heights were 4.04m, 5.04m, 6.04m, 7.04m and 8.04m. The absorber that had 3.0mm hole diameter gave the highest effeciency of 75.4% at a chimney height of 8.04m.