Thermal conductivity group
The thermal conductivity group (WLG) is part of the product description of a building (insulating) material. It indicates the thermal conductivity of a material for a heat flow.
In the course of the harmonization of EU standards, the designation WLG is replaced by WLS ( thermal conductivity level ).
Labelling
The thermal conductivity group or level is derived from the calculated design value of the thermal conductivity λ B according to DIN 4108-4: 2013-02. This value is determined from the nominal value of the thermal conductivity λ D according to DIN EN 13162 to 13171 and an increase factor. Depending on the building material, this can have a value of 1.03 to 1.23.
The rated value λ B of the thermal conductivity level is rounded up in steps of 0.001 W / (m ∙ K), that of the thermal conductivity group in 0.005 W / (m ∙ K) steps to three decimal places, as is e.g. B. can be seen in the information on insulation product labels. A value of 0.032 W / (m · K) thus corresponds to a WLS of 032 and a WLG of 035. It is assumed that the rated value is less than one, as only insulation materials are generally assigned to a WLG. The smaller the WLG value, the greater the thermal insulation effect.
Thermal conductivities, for example, play a major role in compliance with the requirements of the Energy Saving Ordinance (EnEV).
Application in the marking of a thermal insulation material
Example for the labeling of a thermal insulation material:
EPS 035 DAA ie
With:
- EPS: rigid polystyrene foam
- WLG / WLS: λ = 0.035 W / (m ∙ K)
- DAA: External insulation of the roof or ceiling, protected from weathering, insulation under coverings
- ie: high pressure resistance
See also
- Heat transfer coefficient = "U-value" (formerly "k-value")
literature
- DIN 4108-10: 2015. Thermal insulation and energy saving in buildings - Part 10: Application-related requirements for thermal insulation materials - Factory-made thermal insulation materials. Beuth Verlag, Berlin 2015.
- DIN EN 13162: 2015. Thermal insulation products for buildings - Factory made mineral wool (MW) products - Specification; German version EN 13162: 2012 + A1: 2015. Beuth Verlag, Berlin 2015.
- DIN 4108-4: 2017. Thermal insulation and energy saving in buildings - Part 4: Thermal and moisture-proof rated values. Beuth Verlag, Berlin 2017.
- Walter Bläsi: Building Physics. 7th edition. Verlag Europa-Lehrmittel, Haan-Gruiten 2008, ISBN 978-3-8085-4267-5 .
Individual evidence
- ↑ DIN 4108-4: 2017. Thermal insulation and energy saving in buildings - Part 4: Thermal and moisture-proof rated values. Beuth Verlag, Berlin 2017.
- ↑ DIN 4108-10: 2015. Thermal insulation and energy saving in buildings - Part 10: Application-related requirements for thermal insulation materials - Factory-made thermal insulation materials. Beuth Verlag, Berlin 2015.