Automated control strategies of inside slat-type blind considering visual comfort and building energy performance

Windows are the only part in buildings that can directly penetrate the solar radiation into the space and thus the shading devices are needed to control the solar penetration. Among different blind types in office buildings, roll blinds are not operated efficiently and they are usually closed without any operations by occupants. Therefore, optimized control strategies of slat-type blinds are suggested in this study through two stages. In the first stage, double-sided blind was suggested by applying different reflectance between front and back sides of the slat and by fully rotating the slat when the system mode was switched between heating and cooling mode. When the double-sided was used along with the lighting dimming control, 24.6% of the energy saving could be achieved compared to the baseline case and the glare could be avoided at the same time. In the second stage, the control strategies of slat angle and up/down control logic were developed to fully remove the glare and improve the energy efficiency. As a result, 29.2% of energy saving could be achieved and at the same time the chance of glare was only 0.1%.