Glass Coatings and Optical Interfaces: Improving Energy Efficiency and Daylight in Architectural Structures

Introduction. Contemporary architectural approaches prioritise energy-efficient designs that focus on occupant comfort and sustainability. Glass facades and windows are integral to these efforts, providing ample natural light and maintaining visual coherence. However, uncontrolled solar radiation, glare, and poor insulation can undermine a building's thermal comfort and increase energy use. Recent advancements in thin-film coatings for architectural glass present innovative solutions for optimising daylight, regulating solar heat gain, and enhancing thermal efficiency.

Methods. This study investigated various commercially available and prototype thin-film coatings intended for use on architectural glass. Different deposition techniques were examined, including magnetron sputtering and chemical vapour deposition (CVD). The samples underwent testing under controlled laboratory conditions to assess their optical transmission coefficients, reflection properties, and emissivity. Complementary testing in real-world room conditions further enhanced findings, facilitating a comprehensive evaluation of daylight effectiveness, glare reduction, and their associated impact on internal temperature.

Results. The data obtained indicate that multilayer thin-film coatings can substantially enhance solar radiation control by reducing the transmission of infrared radiation by up to 50% while maintaining an improved transmission coefficient for visible light. Additionally, low-emission coatings effectively diminish heat transfer through glass, resulting in an approximately 20% increase in insulation performance compared to conventional uncoated glazing. Measurements of the interior revealed a notable reduction in glare and a more consistent indoor temperature, enhancing residents' comfort.

Conclusions. The findings indicate that thin-film coatings on glass serve as an effective solution for architects aiming to balance the benefits of natural light with thermal and visual comfort. These coatings support sustainable development goals and foster a healthier, conducive indoor environment by optimising solar radiation, mitigating glare, and enhancing insulation performance.