Estimation of daylight illuminance, par, UV-A and UV-B from the solar irradiance

This study aims to propose a method for estimating the daylight illuminance, PAR, UVA and UVB from the solar irradiance. Clear sky index (Kc) and Cloudless index (Cle) is calculated from the solar irradiance. Then precipitable water (W) is calculated from the air temperature and humidity. Formulas to estimate the daylight illuminance and PAR were developed as functions of Kc, Cle and W. In addition, formulas are developed to estimate UVA and UV-B as functions of Kc and Cle. These equations were confirmed satisfactory after the verification by the long-term measurement data in Osaka. The daylight illuminance, PAR, UV-A and UVB are possible to estimate based on the solar irradiance data. The fruits of this study are available for a wider environmental predictions not only building environmental simulation.