OptLab-SPX  Glazing Factors (EN 410, ISO 9050, ISO 13837, etc.)

The norms EN 410, ISO 9050 and ISO 13837 (single glazing only) are applied to determine light and energy parameters of glazing. The resulting values are important for considering the energy requirements of buildings. Basically, the procedures are applied for clear panes, but with an integrating sphere also scattered materials can be evaluated.

The parameters are:

  • Light Transmittance, single glazing
  • Direct Radiation Transmittance/Reflectance, single glazing
  • Secondary Heat Transfer Factor, single/double glazing
  • Total Solar Energy Transmittance (Solar factor), single/double glazing
  • Total Solar Energy Transmittance % (Solar factor), single/double glazingEND
  • UV-Transmittance, single glazing
  • CIE Damage Factor, single glazing
  • Skin Damage Factor, single glazing
  • Degree of UV Transmittance
  • General Color Rendering Index Ra[D65]

Parameter definitions are additionally based on the following norms:

ISO 13837:2008

Road vehicles — Safety glazing materials — Method for the determination of solar transmittance

ASTM E 424-71 (reappr. 1993)

Standard Test Methods for Solar Energy Transmittance and Reflectance (Terrestrial) of Sheet Materials

ASTM G 159-98

Standard Tables for References Solar Spectral Irradiance at Air Mass 1.5: Direct Normal and Hemispherical for a 37° Tilted Surface

ASTM G 173-03

Standard Tables for Reference Solar Spectral Irradiances: Direct Normal and Hemispherical on 37° Tilted Surface

ASTM G 159 and ASTM G 173 only define tables of solar radiation, where G 173 is supposed to replace G 159. Solar Transmittance value are calculated as described in section Weighting Factors. The data tables in both norms do not have equidistant data so that a trapezoidal weighting is applied. This weighting is mentioned in G 173 and explicitly described in ISO 13837.

Both norms also include table data above the usual spectrometer measurement range. For this software. they are reduced to the range 300 (or 305) to 2500 nm.