An advanced numerical model for dynamic daylight and energy consumption analysis of thermal-responsive complex fenestration system with adaptive solar absorption

• Advanced operation model of complex thermotropic window for simulation developed. • Experimental and numerical evaluation for the developed model conducted. • Real physical properties of thermotropic material inputted for simulation. • Energy/daylight performance of complex thermotropic window accurately predicted. • Climate, slat interval and transition temperature impact on results analysed. The integration of Thermotropic Parallel Slat Transparent Insulation Material (TT PS-TIM) smart façade system offers substantial potential for solar regulation, thereby enhancing indoor daylight comfort and overall building energy performance. However, existing simplified operational models, which are primarily based on glass surface temperatures, fail to accurately account for the temperature of TT slat surfaces within this complex system and potentially affect the accuracy of energy and daylight analysis. This study investigated the performance of TT PS-TIM smart facade system for energy-saving and daylight optimization in buildings. Using integrated EnergyPlus and RADIANCE simulations, along with a novel developed and experimentally/numerically validated dynamic control model based on TT slat solar absorption and glass surface temperature, the study evaluated TT PS-TIM’s energy-saving potential and daylight comfort enhancement in various scenarios. The findings from the advanced model revealed that TT PS-TIM systems outperform conventional double glazing (DG) in enhancing daylight comfort, notably increasing Useful Daylight Illuminance ( UDI 300-3000 ) and reducing indoor glare. Additionally, the system significantly reduced cooling energy consumption in summer, though it may slightly increase heating and lighting energy use in winter due to its temperature-responsive solar regulation. Among all scenarios, the system achieved maximum energy savings of 11% compared to double glazing (DG) in London, 16% in Beijing, and 10% in Stockholm. The energy-saving effectiveness of TT PS-TIM systems was influenced by transition temperatures and slat intervals.