Performance Comparison of a Transpired Air Solar Collector with Low-E Surface Coating
Abstract
Transpired air solar collectors are often used to preheat ventilation-air in commercial buildings. Outdoor air is drawn through a perforated, unglazed metal absorber and delivered to a building space in a single pass. Until recently, high-emittance absorber coatings were commonly used, making them susceptible to radiant thermal losses to the surrounding environment. The recent development of durable, low-emittance coatings has allowed manufacturers to offer these surfaces on their unglazed products. This study compares the performance of two transpired solar air collectors: one with a high-emittance absorber coating and the other with a low-emittance coating. Results indicate that, the low-emittance surface coating significantly increased both the efficiency and delivery air temperature compared to the collector with the high-emittance surface coating