Relationship between solar absorptance and color parameters of architectural paints

Abstract

The thermophysical characteristics of the building envelope play a crucial role in managing the thermal load from solar radiation. The use of low solar absorptance coatings is a significant alternative in reducing surface temperatures. In the realm of architectural paints, manufacturers are required to obtain color parameters for each paint produced, but determining solar absorptance is not mandatory. Consequently, the utilization of coatings with known solar absorptance is limited both in the construction market and in built environment performance assessments. The scarcity of measured data, coupled with the high cost and limited accessibility of equipment, contributes to this gap in the field. This research aims to evaluate the relationship between solar absorptance and color parameters of architectural paints, proposing a reliable and precise method for estimating solar absorptance based on internationally standardized measurements. The methodology involves laboratory measurements of spectral reflectance and color parameters for various paints, sample exposure to natural aging and artificial aging tests in the laboratory. Subsequent statistical analysis and development of the solar absorptance estimation method will be conducted for both new and degraded samples. The samples will be exposed in São Carlos/SP for three years in a natural aging station, with semi-annual measurements. The diverse outcomes of this research intend to address a significant gap by providing updated and accurate national data on solar absorptance for both new and degraded paints, contributing to the clarity of information for assessing thermal and energy performance in buildings and design considerations. (AU)