Structure, Mechanism, and Application of Vacuum Insulation Panels in Chinese Buildings

Abstract

Thermal insulation is one of the most used approaches to reduce energy consumption in buildings. Vacuum insulation panels (VIPs) are new thermal insulation materials that have been used in the domestic and overseas market in the last 20 years. Due to the vacuum thermal insulation technology of these new materials, their thermal conductivity can be as low as 0.004 W/(m⋅K) at the center of panels. In addition, VIPs that are composites with inorganic core and an envelope out of commonly three metallized PET layers and a PE sealing layer can provide B class fire resistance (their core materials are not flammable and are classified as A1). Compared with other conventional thermal insulation materials, the thermal insulation and fire resistance performances form the foundation of VIP's applications in the construction industry. The structure and thermal insulation mechanism of VIP and their application potential and problems in Chinese buildings are described in detail.

Experimental Verification of Theoretical Ageing and Service Life Prediction Model for Vacuum Insulation Panels

“…The smaller the porous size of the core material is, the lower the thermal conductivity is (Peng et al, 2016). However, the core material has to be an open cell to evacuated air entirely to eliminate convection and conduction through it.…”

“…Where kB is the Boltzmann constant which equals to 1.38X10 -23 JK -1 , T is temperature (K), Φ is the pore size of the pores(m), and P is gas pressure (Pa), d is the diameter of the gas molecule (m) (Caps et al, 2008;Wegger et al, 2011;Alotaibi et al, 2014;Peng et al, 2016). Equation 6is used to evaluate the Knudsen number for VIPs at 25 • C.…”

“…In Equation 8, for the temperature under 150K, the thermal conductivity of radiation is extremely low and can be neglected (Peng and Yang 2016). For the sake of simplicity, most theoretical approaches neglected the coupling of λcop and λw in Equation 1.…”

“…Moreover, the core material has to be an open cell structure to permit any gas within it to evacuate. The material has to be stable enough to tolerate the pressure load of about 1 bar or 100 KN/m 2 for the evacuating process (Peng et al, 2016). In 2009, research was done by J. Kwon and et al on three mechanisms of thermal transports through different filling materials: 1-powder, 2-foam and 3-fibre with the staggered beam.…”

Experimental Verification of Use of Vacuum Insulating Material in Electric Vehicle Headliner to Reduce Thermal Load

“…Unlike conventional insulation, vacuum insulation creates a vacuum inside the headliner, and heat transfer is blocked because of the vacuum structure. The resulting heat insulating performance is better than that of conventional heat insulating materials, and even for low material thicknesses, the heat insulating performance is equivalent to or greater than that of existing heat insulating materials [23][24][25][26].…”