Mar 5 2008
The LockPlate® composite system provides efficient thermal insulation for the facades of buildings. A vacuum enclosed in special panels reduces the exchange of heat. LockPlate® is easy to handle and much thinner than conventional heat insulation systems.
A well insulated house saves a lot of energy. This is why building designers constantly strive to develop new and improved thermal insulation systems. Styrofoam, rock wool, cork, hemp fibers – the materials most sought-after are those that have low thermal conductivity and thus reduce the exchange of heat between the outer and inner walls. However, because of the rising standards, thermal insulation in houses is getting steadily thicker despite the relatively low heat conductivity of the insulation materials. Conventional insulation materials such as styrofoam or wool are not fully able to prevent the exchange of heat because air or other gases are trapped in their interstices.
Vacuums provide the solution. Working with two industrial partners, Porextherm Dämmstoffe GmbH and Maxit Deutschland, researchers at the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg have developed vacuum insulation panels – VIPs for short – to a point where they are suitable for thermal insulation in construction work. The principle is similar to that of a thermos flask: “The vacuum insulation panels are made up of a porous supporting structure encased in a special film that is not permeable to water vapour and gas,” explains ISE project manager Dr. Werner Platzer. “These bags are evacuated to just a few millibars and sealed. This greatly restricts the mobility of the few air molecules in the pores. As a result, the air’s thermal conductivity is suppressed and hardly any heat is exchanged.” However, sharp objects can easily damage the film – which would quickly destroy the vacuum. The scientists have therefore additionally encased the VIPs in polystyrene foam. All in all, LockPlate® is a practical composite thermal insulation system that is very easy to handle on a building site. “The panels are so designed that 95 percent of the overall wall surface can be covered with only three standard sizes,” says Platzer. “The panels can be cut to shape in certain places. That was never possible with other vacuum insulation systems.”
The thermal conductivity of the VIPs is ten times lower than that of other insulation materials such as styrofoam. LockPlate® is expected to be certified as a building system very soon. What’s more, it is significantly thinner: While conventional composite heat insulation systems in a passive house have reached thicknesses of 20 to 30 centimeters, the LockPlate® system is only about nine to eleven centimeters thick – an argument in its favor, where architects are concerned. LockPlate® is also eminently suitable for insulating older buildings undergoing renovation.