Volume 42: Energy Transitions toward Carbon Neutrality: Part V

Influence of control strategy and split-band spectral modulation on the energy performance of electrochromic smart windows ShuangduiWu, Hengxin Zhao, Yifan Wu, Hongli Sun, Borong Lin

Abstract

Electrochromic smart windows represent advanced adjustable envelope technology, where the solar radiation transmittance can be dynamically adjusted in response to changes in the applied voltage, thus demonstrating superior energy-saving potential. In this paper, a cell room office located in a multi-story office building was constructed in DesignBuilder to explore the effects of window-to-wall ratio, outdoor temperature-based control strategy, and spectral modulation characteristics on the energy performance of electrochromic smart windows. The conclusions show that for Helsinki, Beijing, and Miami, electrochromic windows with visible modulation spectral characteristics are more energy efficient compared to near-infrared modulation spectra, and this phenomenon is more pronounced with larger window-to-wall ratios. Selecting a suitable control strategy can make the electrochromic window adapt to change the transmission state with the change of weather conditions and achieve the best energy saving effect. The energy-saving effect of triggering the electrochromic window state change at 15℃ is better than that at 27℃. It is hoped that this paper will enable electrochromic windows to contribute in a small way to the field of effective solar energy utilization and solar thermal management and to promote the development of smart window technology.

Keywords electrochromic windows, adjustable envelope, solar energy utilization, solar thermal management, control strategy, solar modulation