Study of Direct Solar Radiation to Indoors and Secondary Formation of Ultrafine Particles

摘要

The secondary formation of ultrafine particles in indoor environment is reported in several studies and the reaction of VOCs by UV ray is estimated to explain the phenomenon. In this study, the authors focus on indoor UV field by the direct solar radiation and its characteristics are estimated by the UV intensity and the indoor volume shot by direct solar radiation where the reaction may be possible. The case study is conducted in Tokyo by computer simulation with the parameters such as date, time and the window direction. The highest effect is estimated in summer season at the case where the window direction is east or west. Furthermore, field survey is conducted in summer season to comprehend the phenomenon by measuring ultrafine particles, solar radiation, etc.