Abstract
In contrast to exterior materials, house interior materials are not directly exposed to rain and only receive the sunlight that penetrates through window glass. Recently, various kinds of double-glass panes have often been used for windows in Japanese houses in place of a conventional single-plate glass. Wavelength and irradiance of transmitted light vary greatly according to the kind of window glasses. Therefore, to establish a method of evaluating the photo-stability properties of interior materials, we designed a new accelerating-test apparatus with a metal halide lamp as the light source and a pane of glass between the lamp and the samples. Both the spectrum of transmitted sunlight through glasses and that of transmitted light in this apparatus were measured.
With respect to the spectrum of transmitted sunlight through glasses, the irradiance decreased especially in the low wavelength of the ultraviolet range, in the order of single glass, double glass, low emissivity double glass, solar reflection double glass, and laminated solar reflection double glass. On the other hand, the spectrum of transmitted light in this apparatus showed similar changes, especially in the ultraviolet range. These results prove that the apparatus is effective in the evaluation of the photo-stability properties of house interior materials.
