During the service life, climatic conditions have a great influence on the degradation of VIPs. Firstly, permeation
of dry atmospheric molecules(O2, N2, CO2, etc.) through a more or less permeable barrier film surface or the edges
and seams will contribute to the vacuum deterioration. Secondly, water vapor infusion will cause the total pressure
increase[5]. Not only the pressure increase within the VIP but also the penetrated water vapor that is adsorbed by the
core material will lead to a direct increase in the thermal conductivity of the evacuated porous core materials[6].
Thirdly, the degradation effect is also related with panel size and outgassing rate of the core material in a VIP. A
review on vacuum degradation research will be focused in the first part of this paper.