Experimental Evaluation of the Thermal Performance of an Architecturally Integrated Solar Air Heating Façade

Towards the mitigation of climate change effects and the achievement of energy efficient buildings and high levels of occupant comfort, envelope technologies have gained high scientific interest. Trombe Walls (TWs) or Solar Air Heating Facades (SAHFs) contribution to heating needs reduction has been studied in various studies over the years, nevertheless there is still need for further investigation to fully understand all their potential benefits for a building. In this study, the results of an experimental campaign conducted in a residential building in Turin (northern Italy), where a full-scale TW module was examined, are presented. The examined module is a double-skin envelope component consisting of the existing massive masonry wall, which exhibits a black-colored external side, and a semi-transparent multicavity polycarbonate layer, which together enclose a cavity where the air is heated exploiting solar radiation. The operating mode of a Supply Air Façade (SAF) was tested. A fan providing about 43m3/h (1519ft3/h) of air flow rate was used. The results indicate the high heating capacity of this system, as a significant heating of the cavity air was recorded. Indeed, the cavity temperature reached close to 55 °C (131°F). This value corresponds to an efficiency in exploiting the solar gains close to 14%, potentially reaching 18% without shading.