SCHOTT GlassX: optically like glass, thermally like concrete
At BAU 2013, the SCHOTT technology group will be presenting SCHOTT GlassX crystal, a façade solution that integrates four system components – transparent thermal insulation, protection from overheating, conversion of energy and thermal energy storage – into a single functional unit. GlassX crystal contains a Phase Change Material (PCM) that absorbs excess heat and then releases it during the colder evening hours. This globally unique façade module thus offers the combined advantages of glass façades and massive walls. This means it allows for as much light as a glass front to pass through and still stores more thermal energy than a concrete wall. “SCHOTT GlassX allows for architecture to be realized that relies heavily on glass, yet meets the mandatory criteria that apply for an energy-efficient building,” explains Dr. Martin Rüttgers, Vice President of SCHOTT Architecture + Design.
A thermal storage module that absorbs, stores and then releases solar energy as pleasant radiant heat is the main element of SCHOTT GlassX crystal. A salt hydrate that is hermetically shrink-wrapped inside a polycarbonate container serves as the PCM. When subjected to intensive solar radiation, it melts and stores energy that would otherwise result in uncomfortable overheating of the interior of the room. The PCM discharges by releasing heat by way of crystallization during the cooler evening hours and at night and thus allows for a closed charge and discharge cycle. As a glass façade, the triple insulation glass structure of GlassX crystal offers thermal insulation with a U-value of under 0.5 W/m²K. A prismatic panel located between the panes reflects back the rays of the sun in the summer at angles of incidence of more than 40° (= total reflection of solar radiation). In the winter, on the other hand, the radiation is allowed to pass through the sun protection at full intensity to bring as much heat and light into the building as possible. On the room side, the module is enclosed by a single pane of 6 mm safety glass. The interior surface can be custom designed and therefore offers considerable freedom of design. “As functional multiple insulating glass, GlassX crystal reduces energy consumption with respect to controlling the temperature and artificial lighting. At the same time, the translucent wall contributes to both higher thermal and living comfort,” explains Product Manager Erik Richter. Other advantages: the elements contain no mechanical components or electronic controls, therefore passive solar energy generation is completely maintenance free, yet offers a high degree of functional reliability.
GlassX crystal comes in thicknesses of 62 to 86 mm. Façade builders can install these elements just like conventional insulating glass. Flexible use is made possible by the fact that there are various sizes to choose from: The elements can be used to form a surface of up to six square meters, 3,000 mm in height and 2,000 mm in width.
The SCHOTT GlassX store version is available in the same size as a single pane glass element without a prismatic panel for use in interior applications, for instance as a partition or mobile element. Here, too, it offers the full effect of GlassX with respect to storing solar radiation and absorbing internal heat loads or achieving a warming effect in the afternoon and evening hours in the winter. This could well eliminate the need for an air-conditioning system or allow for a much smaller system to be used in buildings with curtain wall façades or renovation projects.
SCHOTT is an international technology group that sees its core purpose as the lasting improvement of living and working conditions. To this end, the company has been developing special materials, components and systems for 125 years.Learn more