Field measurement of solar reflectance was carried out on the building rooftop where high reflectance paint has been coated already. And solar reflectance of the white test plates was measured on the building rooftop of three universities. Then, several accelerated aging tests are reviewed based on the literatures, and an accelerated aging test is tried to apply for test plates coated with high reflectance paints. Reduction of solar reflectance is significant in about 2 or 3 months after coating and varies about 10 - 25 % in several years after coating. Solar reflectance of the white test plates set on the building rooftop of three universities fell around 5 to 10 % in about 50 days after coating. Most of the dirt components are carbon. Both reduction of dirt immediately after the painting and coating degradation by choking over a long period affect the temporal change of solar reflectance.
Various kinds of brine is used as a secondary refrigerant. Recently, some new brine is proposed, and the brine using potassium acetate aqueous solutions is paid to attention because the environmental load can be decreased. We investigated the fundamental properties of potassium acetate aqueous solutions, such as refractive index, density, specific heat and viscosity. The measurements of fundamental properties were performed in the temperature range varied from 5 to 50 °C for measurements of refractive index and specific heat, 0 to 70 °C for density and 0 to 50 °C for viscosity, while the concentration range varied from 0.0 to 50.0 wt% for measurements of refractive index, density and specific heat, 10.0 to 50.0 wt% for viscosity. In addition, the empirical equations of these properties are presented and are in good agreement with experimental results.