Vacuum Insulation Panel
The measure of the rate at which heat flows through an insulant is known as the thermal conductivity (k-value) or, alternatively, the R value. Heat transfer through a volume occurs by three modes: convection, conduction and radiation.
Traditional insulants work by blocking convection by means of a matrix of fibres or bubbles where the voids are filled with air. The performance of an insulant is therefore determined by the thermal conductivity of the air within it, plus the transfer capability of the material itself. Replacing the air with a less conductive substance, or blowing agent, improves the overall performance of an insulating material. Removing the gas altogether to create a vacuum offers even better performance – both convection and conduction require the presence of gas molecules to transfer heat energy, so neither can take place.
VIPs are rigid boards that have a microporous core made of three components: fumed silica, an opacifier and organic fibres. This core is evacuated of air to create a vacuum, encased and sealed in a thin, gas-tight envelope. The key advantage of VIPs is their low thermal conductivity: K values of 0.0045W/mK can be achieved. In comparison, the thermal conductivity of expanded polystyrene (EPS) insulation is typically 0.031 to 0.038W/mK.
The table opposite illustrates how laying additional insulation on top of the existing concrete slab can affect ceiling heights. It assumes a typical existing floor construction of a 100mm concrete slab with 75mm sand and cement screed on top, which can be removed, and a standard sized VIP of 25mm, in comparison to 100mm EPS, in order to achieve a U-value of 0.25W/m2K.
In many cases, the use of VIP actually results in a small increase in floor-to-ceiling height, whereas the use of EPS can result in a loss of up to 9cm.
This could require remedial work to skirting boards, radiators and door lintels to account for this jump in height.
As a matter of fact,the fumed silica VIP is more suitable while applied in constructions, it has higher compressive strength, very low thermal conductivity, and super insulation properties.
A large number of research shows that in the field of construction,lifespan of fumed silica VIP can reach more than 60 years, 10 times longer than Vacuum Insulation Panels with fiberglass or microsilica kernels.
The size can be tailored or standard which is shown as below:
Vacuum panels can be prepared in different shapes, geometry and sizes, as showed in the following pictures: