increase in VIPs with different foi

increase in VIPs with different foils and panel sizes were tested under specified conditions of different temperatures
and relative humidities by Schwab etc[16]. It can be concluded that the air and vapor transmission rates of the foil
covers depend on temperature, relative humidity, foil type and panel size. The higher the temperature and humidity,
the lager pressure increase occurs in VIP, which can be contributed to the concentration difference and the
transmission ability of gas and vapor. It is interesting that if the panel circumference L is doubled, approximately
one half of the rate of pressure increase occurs. The author indicated that the pressure increase is mainly caused by
the length-related gas transmission rate[16]. The influence of moisture on thermal conductivity also has been
investigated. The increase is about 0.5..10-3 W/(mK) per mass% of water. For typical middle European climate, a
maximum moisture content of about 6 mass% can be expected, which corresponds to a maximum increase of
thermal conductivity of about 3..10-3 W/(mK) for VIPs with fumed silica kernels[17,18]. Martin etc.[19], from a
real construction perspective, gave an overview of the requirements for and the behaviours of VIPs integrated into
building components and constructions according to the results of predecessors.