Daylighting and visual comfort performance of integrated dynamic roller shades and lighting controls

Full-scale testing was conducted to assess the performance impacts of automated dynamic roller shades and integrated lighting control on daylighting and visual comfort of perimeter office spaces. This work specifically focuses on the east and south orientations, and comparison of performance of the integrated dynamic shading and lighting in these orientations. Two parallel test rooms in each orientation are used, including a baseline room without, and a parallel room with dynamic shading and lighting. A custom control strategy is developed and integrated into the existing building automation system (BAS) with the goal of optimizing daylight utilization, visual comfort, and energy savings. The multistep control algorithm uses feedback from interior illuminance sensors to adjust the height of the shades and electric lighting levels. Variable interval control logic was utilized to control the interior roller shades at arbitrary intermediate heights during the control strategy application. Daylighting performance and visual comfort are assessed using useful daylight illuminance (UDI) and simplified daylight glare probability (DGPs), respectively. Spatiotemporal distribution of daylighting at different distances from the window are also presented. Results from over 7 months of testing across a range of sky conditions and solar angles, with an average of 50% in measured lighting energy savings, indicate that both visual comfort and daylight availability is maintained within the desired range more than 85% of the time, compared to less than 50% without the dynamic shading and lighting.