ETH spin-off Aeroskin Tech is developing innovative thermal insulation that uses aerogel technology to insulate buildings more efficiently and sustainably. This new insulation has an energy-saving effect and is significantly thinner than conventional materials – a mere 10 centimetres instead of up to 30 centimetres, depending on the application.
When winter arrives and the temperature drops, we can either put on some warm clothing or turn up the heating and live with the additional costs. But what if the solution for a warm and energy-friendly home lies in the walls of the building? The more effectively buildings are thermally insulated externally, the less energy it takes to heat them internally. This is where ETH spin-off Aeroskin Tech comes in.
The company is developing a new kind of thermal insulation that insulates twice as well as conventional materials. “We want to provide sustainable and efficient building insulation,” says Daniel Sanz Pont, founder of Aeroskin Tech and senior scientific researcher in the group led by Robert Flatt, Professor of Building Materials at the Department of Civil, Environmental and Geomatic Engineering at ETH Zurich.
Aeroskin Tech offers different solutions depending on a building’s needs: for example, an ultra-high performance spray plaster that is applied to the façade, ultra-high performance insulating boards that can be used as conventional products or for tailor-made prefabrication in combination with digital fabrication and 3D building scans. These prefab elements can be rapidly attached to a building’s walls.
The insulating material offers two to two-and-a-half times better insulation than conventional products such as wood fibres or rock wool. What’s special about Aeroskin Tech products is that a thickness of around 10 centimetres is already enough to achieve optimum building insulation.
By comparison, conventional rigid foam boards are up to 30 centimetres thick. “The requirements vary depending on whether a building is renovated or a new build and whether the new build is constructed according to Minergie standards,” says Sanz Pont.
The secret: a material from the aerospace industry
The thermal insulation produced by the ETH spin-off is based on an aerogel. These materials were originally used in the aerospace industry as high-performance insulators for electronics and other sensitive components. “When I began studying aerogels some 15 years ago, they weren’t very common. But I quickly realised their potential for applications such as the thermal insulation of buildings,” says Sanz Pont, whose doctorate is in aerogel composites.
“An aerogel is essentially a dried gel. Unlike normal gels, however, it does not collapse when dried but maintains its volume. It has a nanoporous structure,” explains Sanz Pont. This structure is ideal for insulation. Conventional insulating materials are also highly porous, consisting of up to 90 percent air in some cases, where heat is mostly transmitted by collisions between air molecules.
In a nanostructure, however, the pores are so small that the air molecules collide with the pore walls more often than they do with each another. “This is called the Knudsen effect,” says Sanz Pont. “It’s what makes aerogels the best thermal insulators of all.” This drastically reduces the heat flow from the building’s interior to the outside, for example. In a dry aerogel, the air molecules are more isolated from each other. Thanks to this effect, the hot air remains inside the house and cannot escape through the material to the outside, as it is prevented from doing so by the reduced convective effect inside the aerogel.
The project description is provided by ETH Zurich.
