Experimental Investigation and Optimization of a Glazed Transpired Solar Collector

Abstract

Solar air collectors are increasingly used nowadays due to their important potential in reducing the energy consumption of buildings. In this context, glazed transpired solar collectors (GTCs) represent an interesting solution, but this type of solar air collector is less studied. Consequently, the objective of this work is to thoroughly assess the performance of a GTC prototype under real long-term climatic conditions. First, the design of the GTC is optimized based on methodically experimental tests. The results show that the GTC configuration with a 30 mm air gap among the absorber and the glazing leads to improved heat transfer efficiency and superior global effectiveness, regardless of airflow rates through the solar air collector. This optimized GTC configuration is further studied by integration within the façade of a full-scale experimental building (container-type, light structure). Comparative experimental studies are then carried out concerning the heating energy consumption and ventilation load of the experimental building without/with GTC implemented in the ventilation system, under Bucharest real weather conditions. The data achieved indicate that the GTC prototype is capable of substantially reducing the ventilation load: up to 25% for low solar radiation (below 200 W/m2) and over 50% (achieving even 90%) for moderate solar radiation (between 250 and 380 W/m2). Finally, for high solar radiation (over 400 W/m2), the GTC outlet air temperature exceeds the interior temperature set-point (22 °C) of the experimental building.

Keywords

• glazed transpired solar collectors (GTC)
• building ventilation
• experimental measurements