3D thermal modelling of complex facades
New meshing algorithms
Presented on October 9, 2024 at Facade Tectonics 2024 World Congress
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Overview
Abstract
Today’s building enclosures face ever greater demands regarding their thermal performance. In cold climates, the required total U-value of the façade is often very low. With thicker insulation layers, the relative impact of thermal bridges increases. Point thermal bridges, such as façade anchors, are due to single penetrations of the insulating layer. More and more, their impact is required to be calculated to account for the heat loss through them.
At the same time, BIM (Building Information Modelling) and the proliferation of easily accessible modelling tools such as Rhino have made 3D modelling of building enclosures pervasive. Performing a thermal calculation of a façade containing small point thermal bridges is however not straightforward, as this poses a 3D problem with large differences in the level of geometrical detail in the model.
In this paper, a new meshing algorithm is described that allows to solve complex 3D thermal problems consisting of larger models containing smaller, significant, details. The meshing algorithm is adaptive, creating non-conformal meshes with smaller meshes in some areas and larger meshes in others. This new meshing algorithm is implemented in SOLIDO, by Physibel. When importing STL geometries of a façade in SOLIDO, the new meshing algorithm results in thermal models consisting of a smaller number of calculation nodes. The significantly lower calculation time is shown in a case study of the calculation of a balcony slab thermal bridge.
Authors
Wout Parys
Partner at Physibel
wout.parys@physibel.be
Piet Houthuys
Senior developer at Physibel
piet.houthuys@physibel.be
Keywords
Paper content
1. Introduction
Today’s building enclosures face ever greater demands regarding their thermal performance. In cold climates, the required total U-value of the façade is often very low. With thicker insulation
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[1] ASHRAE Standard 90.1-2022—Energy Standard for Sites and Buildings Except Low-Rise Residential Buildings
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