Sommer Informatik of Germany has modified its proven WinIso software solution for thermal calculation of windows and facades in construction to meet the revised EN ISO 10077-2:2017 standard.

The optimised software solution has been validated by ift Rosenheim (Institute for Window Technology), an internationally active, technical-scientific service provider and testing institute for construction products.

WinIso is used to calculate two-dimensional heat and moisture vapour flow, isotherms, Uf and psi values with a CAD interface. This provides important data to define the thermal insulation properties of frame profiles and to integrate them into the building design.

According to Roland Steinert, external technical consultant to Sommer Informatik, the revision of the ISO 10077-2 standard for the calculation of building physics values changed the methods of calculation of Uf values significantly.

“In order to meet the requirements of the revised standard, the WinIso software had to be modified accordingly. The integrated CAD Editor and the finite element method (FEM) calculation, in compliance with the revised standard, enable the user to get a more detailed calculation result – especially in the case of semi-ventilated cavities.”

“The improved method allows a separate evaluation of radiative heat transfer and convection, which is much more efficient. And for some frame sections, the new method can result slightly better Uf values,” he says.