Experimental Investigation of Large-Area Transpired Solar Air Collectors
Abstract
Single-pass transpired solar air systems are one of the most cost-effective solar thermal technologies available in the market due to their simplicity and robustness. While most experimental work in this area deals with small samples, the present work evaluates the performance of a large-area transpired solar air collector operating under natural atmospheric conditions. The collector array evaluated was unglazed and was equipped with a perforated metal absorber panel through which air was drawn and heated during operation. The absorber surface was coated with a spectrally-selective Low-e coating. Tests were performed between December 2023 and March 2024 at the Canadian National Solar Test Facility (NSTF) located in Mississauga, ON, Canada. During monitoring, the thermal performance of the installation was evaluated at two air flow rate conditions, typical of real installations. Although integrated into the building’s wall, the system was not connected to the building ventilation system to allow for continuous operation for the study. This provided a level of operational independence that is usually not possible in field evaluations. The present work presents the results of the experiment with an analysis of the collector’s efficiency as a function of ambient air temperature, wind speed and air flow rate