Selective Absorber Coatings Qualification - ISO 22975:2014 Full Application
Abstract
The main R&D challenges in the development of Solar Thermal Collectors are focused on increasing reliability and long-term performance stability. Absorber coatings have a major role in conversion of solar radiation into thermal energy. For this reason, testing procedures for qualification were developed and are described in ISO 22975-3:2014. Full application of the test methodologies proposed in ISO 22975-3:2014 is seldom referred for commercial absorber coatings commercially available. This work reports the results of the full tests to five absorber coatings (commercially available), two obtained by physical vapor deposition (PVD) and three by air spray with selective paints. Additional results, obtained with different accelerated aging tests including salt spray and/or sulfur dioxide and nitrogen dioxide as contaminants, are presented. The advantages and limitations of the methodologies proposed in ISO 22975-3:2014 will be discussed, as will be analyzed and proposed new methods of accelerated aging tests.
Keywords
Solar thermal collectors, Absorber coatings, Qualification tests