Optimization of Natural Lighting and Insolation in Buildings with Curved Facades

Abstract

The design and principle of operation of smart window with a grating optical filter having an angular selectivity of light transmission due to alternating transmissive and chromogenic parallel thin-film strips on the surfaces of the chamber of a double-glazed window are described. Unlike conventional smart windows, the entire area of which is covered with thermochromic, thermotropic, photochromic, electrochromic, gasоchromic, etc. thin films, a grating filter in the active (colored) state of a chromogenic material weakens or completely blocks direct solar radiation by allowing diffused sky light and reflected light to pass through, that is, it improves the quality of illumination. The strips of the filter gratings can be positioned at any slope angle, adapting them to the trajectory of the sun relative to the window, taking into account its azimuth, which favorably distinguishes the filter from horizontal or vertical blinds. Methods for calculating the slope angle of the gratings, their relative position on the surfaces of the window and the widths of the transmissive and chromogenic strips of both gratings are presented. The optimal slope angles of the filter gratings for windows with different azimuths of a building with round facade and the temporal characteristics of the light transmission of these windows are calculated. The results substantiate the advisability of using smart windows with grating filters in buildings with curved facades to improve the comfort of daylighting and insolation, to protect against direct rays when passing diffuse sky light and albedo by adapting the light transmission of windows to a change in the position of the sun relative to them.