Preparation And Energy-saving Evaluation Of Color Heat Reflective Coating

With the development of architecture engineering and improvement of the people pursuit on buildings comfort, the energy consumption on buildings is increased continually in China, which has become one of the three largest fields of energy consumption, in company with industry and transportation. And refrigeration energy consumption in summer has reached one-in-three of the building energy consumption. Heat-reflective coatings can reflect a large fraction of incoming sunlight and keep the building surface at a low temperature, which reduces the cooling load of buildings and has been used more and more widely in building energy conversation design. In recent years, the heat reflective coatings applied to the building are mostly white and light colored, which is difficult to meet the requirement of building color.This paper mainly research on infrared reflective pigment which is the key part of color heat reflective coatings. The impact of Fe2O3、Sb2O3 and Al2O3 content on the compound pigments property is analyzed. TiO2 is the host component in compound pigments and the mainly properties include phase composition, color characteristic and near infrared reflectivity. The substitution of Fe2O3 for TiO2 in compound pigments resulted in the new phase Fe2TiO5. The color changed from white to light yellow and the near infrared reflectivity decreased. Content change of Sb2O3 in compound pigments has no influence on the phase composition, but the brightness coefficient and near infrared reflectivity increase. Content change of Al2O3 has no significant influence on phase composition, color characteristic and near infrared reflectivity of compound pigments. The function of Al2O3 in compound pigment is acting as grinding additives, and the content should be controlled 4%~8%.According to the impact of oxides composition on performance of compound pigment, the yellow, red brown and black pigments and corresponding color coatings are prepared respectively. The light yellow pigments have the maximum solar light reflection rate of 83.1%, the earth yellow pigments have the maximum solar light reflection rate of 79.7%, the red brown pigments have the maximum solar light reflection rate of 52.4%, and the black pigments have the maximum solar light reflection rate of 44.5 %.Through the simple heat transfer model established and choosing Beijing area as an example, to calculate the effect of heat reflective coating on building energy consumption in winter and summer. The energy saving property of multi-story residential buildings, temporary color steel buildings and high-rise commercial buildings are discussed, and some reasonable advices are given upon the application of heat reflective coatings. To multi-story residential buildings, the coatings have the best energy saving effect when applied to the building roofs. On temporary color steel buildings, heat reflective coatings are advised to use on roofs and the east and west walls. For high-rise commercial buildings, heat reflective coatings coated on the glass curtain wall are of great significance on building energy saving.