Effect of retro-reflecting transparent window on anthropogenic urban heat balance

Solar heat shielding against solar radiation over the entire building envelope is one of the most effective measures for achieving air-conditioning energy savings and preventing heat-island phenomenon in warmer climate regions. For this purpose, we proposed a new heat-shielding film, which possesses a retro-reflective property and a wavelength-selection property, while having the same degree of transparency as that of transparent glass. The proposed film can be easily applied to a wide variety of buildings and architecture, including new and existing buildings. This film embodies an innovative heat-shielding technique that makes it possible to effectively return solar radiation toward the sky, while minimizing the secondary effects to other buildings, to the ground, and so on. In order to verify these effects, several aspects of quantitative evaluation are demonstrated. The measurement results and concepts in this paper are referred to from the previous conference paper Inoue et al. [10].