BS EN 12898 is a European Standard on glass in buildings.
BS EN 12898 specifies a procedure for determining the emissivity at room temperature of the surfaces of glass and coated glass.
The emissivity is necessary for taking into account heat transfer by radiation from surfaces at the standard temperature of 283K in the determination of the U value and of the total solar transmittance of glazing.
The procedure given in BS EN 12898 is based on spectrophotometric regular reflectance measurements at near nominal incidence on materials that are non-transparent in the infrared region. Thus, it is not applicable to glazing components with at least one of the following characteristics:
However, the method given in BS EN 12898 can be applied with caution to any glazing component, provided its surfaces are flat and non-defusing, and it is non-transparent in the infrared region.
BS EN 12898 that explains determination of emissivity of glass in building can be used by:
BS EN 12898 that explains determination of emissivity of glass in building takes account of Fourier Transform Infrared (FTIR) spectrophotometers where the spectral range is limited.
BS EN 12898 describes a method whereby spectrophotometers can be used to determine emissivity if they are able to measure up to the 24th ordinate point and if they satisfy a noise criterion for this spectral range. It allows the inclusion of data from the 25th ordinate point up to the 30th ordinate point.
By using BS EN 12898 best practice guidance, you will be able to effectively assess emissivity of glasses in buildings and reduce or increase heat transfer, as per requirement.
BS EN 12898:2019 is the UK implementation of EN 12898:2019. It supersedes BS EN 12898:2001, which is withdrawn.
The main changes compared to the previous edition are the following:
EN 12898:2019