An Assessment of the Thermal Behavior of Envelope Surface Coatings with Different Colors

Contemporary solar power engineering enables the conceptual interlocking of the shape of a building object with its location, structural design, and external envelope, as well as applied materials. Suitably selected solutions involving the structure, shape, construction, and location of a building can significantly improve the thermal balance of rooms in a building. Particularly valuable and warranted are studies involving various solutions for building partitions contributing to a considerable improvement in the thermal balance of a building. This article presents the results of research on temperature changes on the surface of the external part of a partition coated with layers of different colors. For the lightest coating (white), both the average temperature obtained on the and the maximum temperature obtained on the surface were the lowest. With the darker coatings, these temperatures were both higher. The back analyses that were performed indicated lower and higher absorption coefficients, respectively, for the coating compared with the base value for the red coating. Additionally, it was demonstrated that the average surface roughness (Ra) after tests in a natural environment decreased by 12.1% for the base (red) coating. For the grey and white samples, a more than two-fold increase in roughness was reported, of 198.6% and 202.0%, respectively. The SEM analysis indicated material loss and discoloration on the sample surfaces.