Spectral-selective Glazing Strategies for Energy-Efficient and Adaptive Building Envelopes

Department of Architectural Engineering, Pennsylvania State University, University Park, PA, USA

Abstract

Windows account for 30—10°% of heat exchange across building envelopes and contribute up to 25-30% of total HVAC energy use. Conventional coatings offer limited adaptability to seasonal variations. This study investigates scattering-based spectral-selective glazing strategies within the solar spectrum, with an emphasis on the optical mechanisms governing visible transparency and near-infrared (NIR) heat-gain suppression. A mechanism-driven modeling framework is developed using Mie scattering analysis to examine how particle size, refractive-index contrast, and core-shell configurations affect wavelength-dependent scattering and extinction behaviour. These scattering-based pathways are positioned relative to absorptiondominated thermochromic approaches for dynamic NIR modulation. The results highlight physical trade-offs: while larger dielectric particles enhance NIR shielding, they introduce significant visible haze. Core-shell architectures are shown to partially decouple these effects by engineering effective refractive-index contrast. The findings establish a theoretical foundation for bridging nanoparticle optics with building-scale performance evaluation, identifying design boundaries for future climate-adaptive glazing systems.