Title Deriving Annual Control Strategies for Smart Windows with Integrated Consideration of Thermal and Visual Environments in Curtain Wall Office Buildings
Authors 이수진(Lee, Soo-Jin) ; 송승영(Song, Seung-Yeong)
DOI https://doi.org/10.5659/JAIK.2026.42.1.311
Page pp.311-322
ISSN 2733-6247
Keywords Curtain Wall; Office Building; Smart window; Thermal Environment; Visual Environment; Annual Control Strategy
Abstract This study analyzed the annual thermal and visual environmental performance of smart windows in curtain-wall office buildings located in Seoul using the dynamic building energy simulation program EnergyPlus v25.1.0. A baseline model with typical windows and six smart window control alternatives were established, including always clear, always tinted, and four dynamic control strategies based on solar radiation, daylight illuminance, indoor temperature, and glare. Performance indicators included thermal environment (heating/cooling energy consumption, PMV) and visual environment (DGI, UDI). The results showed that heating energy consumption increased by 14?33%, while cooling energy decreased by 16?35%. Thermal comfort improved in the cooling period (43?107% increase in PMV comfort hours) but deteriorated in the heating and shoulder periods (20?83% decrease). Glare discomfort hours were reduced by 4?97%, indicating strong annual glare mitigation. Daylight performance was qualitatively improved in the useful and overlit illuminance ranges, but performance deteriorated in the underlit range. Through normalization, always clear in the heating period and the glare-based control in the cooling and shoulder periods yielded the best overall performance, with a 6% reduction in annual energy consumption compared to the baseline.