THE insulating panels vacuum can have a thermal conductivity varying between 0.004 and 0.008 W / mK, that is, less than about 10 times that of polyurethane and polystyrene panels.
This feature makes them very interesting in the thermal insulation applications of buildings and in the industrial field because they allow a considerable reduction in thickness. Just to make a comparison, insulating panels 5 centimeters thick vacuum-packed is more or less equivalent to a 40 centimeter layer of polystyrene. A big difference!
But how are the insulating panels vacuum packed? First of all it must be said that these products have a history of a few decades. The first vacuum panels, identified with the acronym VIP by Vacuum-Insulation Panels, date back to the seventies and were developed by the German company Linde AG. The scope of application was above all that of refrigerators and freezers.
THE insulating panels vacuum packs are formed by a core, which constitutes the panel, of pyrogenic silica or ultimately of airgel. However from a nanoporous material from which the air was evacuated, hence the definition of vacuum panels.
Normally the core of the insulating panels vacuum-sealed is hermetically sealed inside a multi-layer sheet of aluminum, nylon or PET, however waterproof and pressure resistant.
Okay, but how long do they last? One of the most important aspects in thermal insulation materials is the duration over time with the same performance: what is the duration of the insulating panels vacuum packed? Much depends on the welding and the sheets, but the tests with the insulating panels state-of-the-art vacuum packs, especially in airgel, have shown that vacuum can be maintained for about 30-50 years.
In light of the advances made by technology, especially in the field of airgel (the so-called 'frozen smoke') it is conceivable that insulating panels vacuum will have a significant development in the thermal insulation of buildings. The advantage of these panels in construction consists above all in ensuring high energy efficiency in very low thicknesses, which makes them particularly suitable for the insulation of curtain walls, terrace floors and walkable flat roofs.