Calculate vacuum glass with WINSLT®

Due to its lighter construction and high insulation values, vacuum glass is increasingly used – especially for the renovation of old buildings and in the field of monument protection. The new WINSLT add-on takes this fact into account. It makes it possible for the first time to carry out an exact, fully automatic calculation of vacuum glazing based on existing ISO/FDIS standards.



Further information on the calculation of vacuum glazing:

product presentation

 Video for the calculation of vacuum glass





WINSLT® is the software solution for calculating light technical, solar and thermal properties of glazing in combination with solar shading.

Any structure can be created in a short time and according to the standards:

ISO 673 -> Ug value
EN 410 -> g-value, reflection, absorption, transmission
ISO 52022-3 -> gtot-value
ISO 15099 / ASHRAE -> Ug value, SHGC value, reflection, absorption, transmission

can be calculated. The software is certified by ift-Rosenheim also generates a declaration of performance and CE marking of the glazing.

In WINSLT® you can import and use your own spectral data sets for coatings, glasses and sun protection. The climatic boundary conditions are freely selectable.

Furthermore, the structure can consist of any number of glass panes and a lamella module is available as an add-on. After your calculation, the performance data determined for the respective product variants can simply be transferred to the declaration of performance and printed out.

Product presentation WINSLT®


  • Extensive database with various products from international glass and sun protection manufacturers
  • Import of own spectral data
  • Boundary conditions according to ISO 52022-3 or freely definable
  • Calculations according to US standard ISO 15099/ASHRAE
  • Calculation of any glass structures
  • Representation of the temperature curve across the cross-section
  • Calculation of reflection, transmission and absorption
  • Preparation of a declaration of performance and CE marking for any glass structures in many language versions


Calculation of the radiation-physical and thermal characteristics according to ISO 15099 with the specifications of ASHRAE.

North American standard ISO 15099 for calculating the thermal performance of windows, doors and sunshades, in some cases, provides two ways to calculate a characteristic value. Therefore, the professional association of all companies in the heating, cooling, ventilation and air conditioning industry in the USA, also known as ASHRAE, makes the stipulation which way to go. The basis of calculation from the standard with the ASHRAE requirements, which partly also include the NFRC standards, are implemented in the algorithm of the software.

Due to the fact that the innovations are mainly in the algorithm of the software, the intuitive handling of the modules WINSLT® Standard and WINSLT® Expert remains. A glass structure can be created in a very short time and then analyzed. An extensive database with various products from international glass manufacturers is available for this, which can be extended as required by importing your own spectral data.

Declaration of Performance / CE Marking

On 1 July 2013, the Construction Products Directive was bindingly replaced by the new Construction Products Regulation. Due to its legal form, the Construction Products Regulation applies equally in all member states. With their introduction, the CE marking has been uniformly regulated throughout the EU. Previously valid national regulations have been dropped. Thus, the CE marking is also binding in all member states.

The declaration of performance replaces the old declaration of conformity. The key difference is that the declaration of performance must be created not just for specific product types, but for each individual product, resulting in increased manufacturer effort. In WINSLT® is integrated the creation of a declaration of performance. After carrying out the calculation in WINSLT®, the corresponding declaration of performance can be printed. The technical values from the calculation are transferred to the declaration of performance.