A promising approach of caved vacuum insulation panel and investigation on its thermal bridge effect

Vacuum insulation panels (VIPs) are excellent adiabatic materials widely applied in various field. Unlike conventional insulation materials, VIPs cannot be trimmed on-site to desired dimensions, necessitating the pre-designing panels to specific sizes. The impact of cavities on VIPs was investigated by numerical and experimental methods in this study. Five cavity shapes for VIPs were involved, that is: circular, equilateral trigonal, equilateral quadrilateral, equilateral pentagonal, and equilateral hexagonal. The variations in thermal insulation performance of VIPs with cavities of different shapes but equal perimeter (124 mm, 500 mm) and equal area (2826 mm2, 6192 mm2) were investigated. The results shew that, the presence of cavities caused sharp reduction of thermal insulation performance of VIPs. VIPs with circular cavities exhibit the lowest effective thermal conductivity (ETC) and thermal bridge effect. For equal perimeter case, the adiabatic performance decreased with increase in the number of sides and corner points. For equal area, VIPs with equilateral quadrilateral cavities exhibit the highest thermal insulation performance among VIPs with polygonal cavities. This work provides valuable insights into optimizing VIPs design for enhanced thermal performance and energy efficiency in various applications. •Cavity design of VIPs is established.•The experimental results are well agreement with the numerical simulation results in comparison.•The effects of cavity shape and size on the adiabatic properties of VIPs are investigated.