Optimizing the thermal performance of the window with horizontal transparent insulation slats: A comprehensive analysis and comparative evaluation

Using slats made of transparent insulation material placed within the insulated glass unit (IGU) cavity can effectively reduce convective heat exchange in the gas cavity and improve windows' thermal resistance. A denser slat arrangement in the cavity of the Window with horizontal Transparent Insulation Slats (WTIS) contributes to better convective suppression within the gas-filled cavity. Still, it also raises concerns regarding excessive heat conduction along the slats. Therefore, further investigation is necessary to explore the optimal structure. In this study, we evaluated the thermal performance of WTIS using a validated numerical model and WINDOW7.8, considering various slat spacing, slat thickness, slat width, and cavity thickness. The air-filling and argon-filling cases were discussed. Furthermore, we experimented with testing the thermal performance of WTIS under different temperature conditions and validated the software calculation results. The results demonstrate that reducing the slat thickness and increasing the slat width is beneficial to improve the thermal resistance. The results identified an optimal slat spacing value of WTIS, which depends on both the cavity thickness and slat thickness and increases with their increase. The thermal resistance of optimized argon-filled WTIS is 39.47%-74.07% higher than that of argon-filled IGU.