Transmaterial

Vacuum Insulation Panels

Cars and homes have at least one thing in common: they consume energy in the form of oil or gas. Energy-efficient vehicles typically make use of lightweight materials and improved engine technologies, and soon home builders will also need to pay greater attention to environmental concerns in their designs. New legislation became effective in Germany last year which stipulates high energy-saving standards for new building construction and a reduction in the heat energy requirements in existing buildings. Apart from modern and efficient heating systems, thermal insulation makes the biggest difference. Vacuum insulation panels (VIP) could well be the material of the future.

Until now, such panels have been used primarily in cooling and refrigeration units. Now they are finding more widespread application as insulators for flat roofs. VIP’s work on the same principle as the thermos flask: when air is evacuated from the cavity of the double-walled container, heat conduction and convection decrease sharply. A metal layer on the surface further reduces the heat transfer by IR radiation. A VIP consists of a filler material such as compressed silica which is vacuum-encapsulated in a plastic barrier foil. “The real advantage is the amount of space that can be saved”, explains Dr. Klaus Noller of the Fraunhofer Institute for Process Engineering and Packaging IVV. “Panels with a thickness of two centimeters insulate just as effectively as 20 centimeters of mineral fibers.” Noller, in charge of Functional Films at the IVV, is working together with three other Fraunhofer institutes and the firm Porextherm Dämmstoffe GmbH to develop panels suitable for use across the entire field of building materials.

The biggest problem they presently face concerns the panel’s service life. Over time, air permeates the barrier film and degrades the effectiveness of the insulation. “The panels work well in refrigerators for up to 15 years. In house construction, however, you need films that hold at least ninety percent of the vacuum after 50 years”, emphasizes Noller. Multilayer ultra barrier films from different polymers are being further developed. In addition, they need to be as durable as possible. “But even when the film itself is damaged, the insulation material inside the VIP still works more effectively than conventional ones”, promises Porextherm Managing Director Hannes Reisacher. [via the Fraunhofer Institute.]

posted by Blaine @ 8:14 AM