U.S. energy savings potential from dynamic daylighting control glazings

Reduced energy consumption and enhanced comfort with smart windows: Comparison between quasi-optimal, predictive and rule-based control strategies

“…Lee [7] analyzed among other parameters the effect of control strategies based on vertical plane incident solar radiation and work plane natural illuminance control, and identified illuminance and glare based strategies as the best to decrease annual energy consumption. Shehabi et al [8] [9]. Results of that study revealed that the developed control strategy, although presenting a good performance, needed a higher range of possible SHGC values for it to fully take advantage of the complexity of the strategy.…”

Dynamic daylight control system implementing thin cast arrays of polydimethylsiloxane-based millimeter-scale transparent louvers

“…This capability not only increases the productivity and well-being of the occupants by adaptively enhancing the visual and thermal comfort, but also substantially reduces the energy usage of the building [2,24,26,27]. It is reported that by combining a dynamic daylight system with automated artificial lighting control, it is possible to save from 30 to 77 percent of the lighting energy [13,30].…”

Measured daylighting potential of a static optical louver system under real sun and sky conditions

“…Of this, a recent estimate by Shehabi et al found that 2.21 quad (60%) is consumed by electrical lighting in perimeter zones located 0-12.2m from the facade during typical daytime work hours (8:00-18:00) [2]. Consequently, the delivery of sufficient daylight from windows has the potential to reduce annual electrical lighting energy demand by minimizing the need for electrical lighting in the perimeter zone during daylight hours.…”

“…However, as a general rule of thumb, conventional windows cannot provide useful daylight beyond approximately 1.0-1.5 times the head height of the window [3], leading to useful daylight for areas within a distance of 0-4.5m from the facade. Subdivision of the window wall into a lower "view" zone and an upper 2 "clerestory" zone for daylight transmission is a common strategy to extend the daylight zone beyond this distance. Because occupants often reduce the daylight transmission of the view zone with shading devices to maintain visual comfort, the clerestory zone is designed to serve as the primary means of daylight delivery into the space.…”