Development of Numerical Heat Transfer and the Structural Model to Design Slim and Translucent Vacuum Layer Type Insulation Panels to Retrofitting Insulation in Existing Buildings

Abstract

Abstract:The authors develop slim and light-weight vacuum insulation panels (VIPs) by producing vacuum layers with spacers and plastic plates. The developed VIPs have the advantages of a low cost and easy installation, thus facilitating retrofitting insulation of existing buildings. In addition, one of the developed VIPs is slim and translucent so it can be easily used for windows in an internal installation. In this paper, the authors first propose a vacuum layer type slim translucent VIP and focus on a reasonable design method. Next, the authors introduce the design process in which the structural design is obtained with element mechanical analysis and a three-dimensional analysis is conducted for the VIP element. In the study, a heat transfer model is used to predict the insulation performance through finite element analysis (FEA). Subsequently, the authors perform an experiment to measure the thermal conductivity in a guarded hot plate apparatus to validate the performance prediction. Finally, case studies are performed to confirm how the different design conditions affect the insulation performance. The optimum design of the vacuum layer type slim and translucent VIP will have a sufficient structural strength to hold and maintain the vacuum layer. The thermal conductivity is approximately 0.007 W/(m·K), which can effectively improve the insulation performance in applications.

Energy conservation using new structured-core and transparent vacuum insulation panels: Numerical simulation with experimental validation

“…Therefore, a silica aerogel spacer with dimensions of Ls= 2.5 mm and a thermal conductivity of 0.02 W/m.K is used between two acrylic plates with 1 mm thickness each. The space between the two consecutive spacers is designed based on a deflection analysis developed by the author in a previous work (Yang et al, 2017). Therefore the δs used in this work is 10 mm, to maintain the deflection between the two consecutive supports less than 0.5 mm (Yang et al, 2017).…”

“…At the same time, keeping the transparency of the window as high as possible is essential for decreasing the lighting energy consumption during the daytime (Yang et al, 2017).…”

Investigation into Window Insulation Retrofitting of Existing Buildings Using Thin and Translucent Frame-Structure Vacuum Insulation Panels

“…The model consisted of two acrylic plates covered with a low emissivity film coating achieved using a transparent gas barrier envelope, and the evacuated space was supported by plastic pillars fixed by a plate. This method achieved very good insulation performance with a thermal conductivity of 0.007 W/(m·K) and a lower production cost than vacuum glazing, meaning this product is effective for retrofitting insulation of existing buildings [19].…”

Development and Validation of Numerical Models for Evaluation of Foam-Vacuum Insulation Panel Composite Boards, Including Edge Effects

“…VIPs have been demonstrated in an additively-manufactured, prototype building [2], building retrofit in a subarctic climate [3], apartments and office buildings [4], among others. Yang et al [5] described the development of thin, translucent VIPs for use in windows.…”