More accurate Psi values for better Uw values 9 January 2018 Back to news index

Brand name profiles and insulating glass now integrated in CALUWIN

More accurate Psi values for better Uw values

Kreuzlingen/Switzerland and Rosenheim/Germany, November 2017.

Glazing and frame profiles have considerable influence on the performance of window installations. This relates to both the energy efficiency and the risk of the formation of condensation at the edge of the glass. This is an area where planners can do a lot right – and a lot wrong. The numerous products available on the market also make choosing the right parts a real challenge. 

CALUWIN, the innovative software from SWISSPACER and Sommer Informatik is a helpful app for window fabricators, architects, energy consultants and building biologists, which calculates and compares the Uw values, condensation and energy savings of a window. An updated version has been created, making the planning process easier and more accurate.

“With several years of experience in developing software for the window industry and continuing product development from SWISSPACER, CALUWIN has become a comprehensive tool. It’s intuitive software,” says Robert Sommer, Managing Director of Sommer Informatik GmbH.

Previously, only representative frame profiles were stored in CALUWIN, but now, specific brand name products can be used in calculation. Karl Theo-Roes, Head of Market Development and Innovation at SWISSPACER explains: “Window installations can now be calculated more quickly and above all, more accurately, as reliable profile data from leading manufacturers is now integrated within CALUWIN. The Psi values for the profile systems, in combination with the insulating glass and spacer bars have been individually calculated by the engineering firm Bauwerk. CALUWIN calculations are now more accurate than the representative Psi values from BF datasheets, resulting in lower Uw values.” To date, profile systems from the brands Gealan, Hueck, Profine and Salamander have already been integrated, with others to follow soon.

Arno Bender, Head of System Support at aluplast stressed: “From our perspective, SWISSPACER and its products play a pioneering role when it comes to minimising the build-up of condensation at the edge of the glass. So, it made perfect sense for aluplast to input its technical data into CALUWIN. In combination with our highly insulating profile systems, we see this as a good opportunity to highlight the better insulating values calculated for our customers.”

In addition to the brand name profiles in the new version of CALUWIN, products from insulating glass manufacturers Saint-Gobain, AGC INTERPANE and Guardian have also been added, with accurate technical product information.

Sebastian Schmidt, Managing Director at Interpane comments: “Our customers look to get product data from both traditional channels such as or tendering databases, and new digital alternatives such as CALUWIN. It complements our systems perfectly and thanks to the market knowledge of SWISSPACER, it’s a tool our customers actively use, so it made perfect sense to include our products also.” 

CALUWIN users can select very specific components from the stored catalogue and thus calculate and optimise the energy related performance of the window. Work is currently underway to include products from other insulating glass manufacturers.

Windows fabricators and installers, as well as manufacturers of profiles and insulating glass, can provide their customers with optimum technical advice using CALUWIN and give them key decision-making information. Sommer Informatik can create custom versions of the app, integrating customer-specific profiles and insulating glass in CALUWIN and adapt the logos and corporate design accordingly.

For the first time, it is now possible for CALUWIN to access accurately calculated Psi values and fRSi values (temperature factor) for any combination of frame profile, insulating glass and spacer bar. “In just a few steps, the accurate Uw value will be calculated and it is immediately clear whether there is a risk of condensation or mould,” said Karl-Theo Roes. “This also makes CALUWIN an excellent tool for pre-planning and advice.” As an alternative to the stored component values, data can also be defined separately and entered manually.

The energy savings calculator compares various window configurations in terms of their efficiency in warm or cold climates. For example, it states the respective requirements for hot air and cooling energy and highlights differences when it comes to energy costs and CO2 emissions. What’s more, CALUWIN determines the various energy ratings in different countries and, where necessary, calculates efficiency classes for Passive House windows in accordance with the guidelines from the Passive House Institute, Darmstadt, Germany.

CALUWIN is available online at and as an App for iOS and Android end devices from the respective App Stores. CALUWIN was developed by SWISSPACER and implemented by Sommer Informatik GmbH, with technical support from the engineering firm Bauwerk. The calculation engine in CALUWIN is certified by ift Rosenheim.