Solar Thermal Collectors Outdoor Testing in Saline Environment

For assessing the efficiency, performance and/or durability of flat plate solar thermal collectors, an accelerated outdoor aging test is proposed, based on salt spraying. The flat plate collector is tested using air as working fluid and without circulation. A testing methodology is proposed along with three evaluation criteria, based on the temperature at the collector's outlet and on the outdoor temperature. The ratio of these two temperatures is found to be relevant in outlining the changes resulted due to accelerated aging of the collector, most likely of the sealing, when micro-cracks allow the fine aerosol droplets to penetrate inside the collector, at outdoor temperatures above 25 °C. The results need inter-laboratory validation and can represent a step forward in defining a novel quality standard.