Double-Glazing Integrated Hydrogel for Enhancing Building Thermal Performance

Abstract

This study explores the integration of hydrogels into double-glazing systems to enhance summer thermal performance, with a focus on the Nankai District of Tianjin. A commercial hydrogel, known for its high absorption capacity and thermal regulation properties, was used to fill a cavity in a double-glazing unit. A hot-box testing system simulated real-world conditions to compare hydrogel-integrated glazing with standard double-glazing units, monitoring temperature variations using thermocouples. The results demonstrate the significant thermal benefits of hydrogel integration. While hydrogel alone reduced transmittance (~ 72%) and heat gain (~ 385 W/m²), the hydrogel–water combination proved more effective. The hydrogel’s thermal buffering capability delayed the temperature rise, particularly during peak sunlight, and exhibited superior infrared radiation-blocking properties. Compared to the unfilled prototype, the shaded unfilled, water-filled, hydrogel-filled, and shaded hydrogel-filled prototypes reduced inner temperatures by 28%, 30.3%, 25%, and 38.5%, respectively, with an overall temperature reduction of 3–9 °C relative to traditional unfilled double-glazing systems. Furthermore, hydrogel demonstrated enhanced heat retention at night, minimising heat loss more effectively than other configurations and maintaining a more stable indoor environment. Overall, hydrogel-integrated double-glazing, particularly when combined with shading, improves energy efficiency and indoor thermal regulation, offering a sustainable alternative to conventional cooling systems.