Daylight and Ventilation Solutions (DVS) exclusively represent Lamilux in the U.K. and we are therefore delighted to report that we offer the worlds first PassivHaus certified rooflight for flat roof installation.
This article sets out to explain what this certification means and why the FEenergysave is the rooflight of choice for PassivHaus projects, as the only certified component.
Most of the countries in the European Union are issuing national regulations as a means of implementing the EU directive on the energy performance of buildings. This directive demands a near-zero energy building standard for all new buildings by 2020, in order to achieve a practically "climate neutral" building stock in European countries by 2050, with an 80% reduction in primary energy requirements. The energy-efficiency qualities of structural components have therefore become an all-important factor in contemporary construction – and PassivHaus design as the highest standard of energy efficiency is now a hot topic.
Once again, as a manufacturer of daylight, SHEV and control systems, Lamilux is able to help architects and planners by supplying innovative, PassivHaus-certified products: the Lamilux CI System Glass Element FEenergysave has been certified by the renowned PassivHaus Institute in Darmstadt, Germany, as the world’s first skylight suitable for passive buildings. This highly energy-efficient daylight element for flat roofs has achieved the top efficiency class, the Advanced Component phA category.
Click here for a full PDF copy of our PassivHaus Certificate
The FEenergysave is the product of further development of the energy-efficient qualities of our time-tested daylight element (Lamilux CI System Glass Element FE). During the course of numerous projects, daylight systems manufacturer Lamilux has integrated both small and large quantities of these elements into the flat roofs of industrial premises, office blocks, school buildings, trade fair and sports halls, prestigious buildings and private houses.
|FEenergysave Rooflight Brochure.|
Click here for a full PDF copy of our FEenergysave Brochure
Twice the efficiency thanks to optimised insulation system
In accordance with the requirements for passive houses, the newly certified skylight unit is always fitted with glazing that comprises three panes, with argon gas between the panes. Two of these glass panes feature a low e coating. The "warm edge" with Super Spacer forms a spacer system. The U value, or heat transmittance coefficient, in the 54mm thick glazing package (Ug) is 0.84 W/(m²K) when installed horizontally.
Lamilux has developed a new insulation system for the frame, consisting of a combined insulation core that unites the insulation block and the insulation web in a single component. The material used in the system makes the daylight element twice as efficient: the glazing support absorbs the heavy load from the glazing elements, while the frame features an extremely low heat transmittance coefficient (Uf = 0.61 W/m²K).
Outstanding heat insulation with a USL value of 0.84 W/(m²K)
A USL value of 0.84 W/(m²K) was determined by the PassivHaus Institute in Darmstadt for the daylight element as a unit, on the basis of EN ISO 10077-1 and 10077-2. A good heat transmittance coefficient is one of the main criteria for successful certification and must be under 1.10 W/(m²K) for horizontal installation in roofs.
Assessors also attach great importance to other aspects, however, when it comes to assuring compliance with PassivHaus requirements. Hygiene plays a significant role: in order to prevent condensation and mould growth, the 12.6°C isothermal line must consistently lie within structures at an outside temperature of -5°C, an indoor temperature of +20°C and a relative air humidity of 50 per cent. The FEenergysave complies with this requirement.
|Cross section and Isothermal diagram - click to enlarge.|
Heat losses are another factor: they are calculated for the frame system and the “warm edge” and expressed by the coefficient ψopaque. The lower this value is, the higher the efficiency class. In the case of the FEenergysave, the coefficient is lower than the maximum value of 0.110 W/(mK) for PassivHaus classification in the phA – Advanced Component class.
Skylight for energy and cost conscious arhitects and planners
"A PassivHaus requires highly energy-efficient components to maintain its high standards" state assessors at the Darmstadt-based PassivHaus Institue. The independant testing centre carries out tests using standardised criteria to give architects and planners a clear idea of energy efficiency in construction components. "We were able to certify that the FEenergysave in the highest efficiency class. This skylight thus offers superior energy-efficient quality".
Thank you for reading this article, if you would like more information about our PassivHaus certified skylights or any of our other energy efficient rooflights please leave a comment below, email us or call 01284 749051.