modelLightTransCoeff

Calculation of direct and global light transmittance throught a window
Diagram of LightTransCoeff

Information

Computation of direct and global light transmittance trought a window with or without shading

Hypothesis and equations

The global and diffuse light transmittance TLW, TLw_dif, TLsw and TLsw_dif should be specify according to EN 410 standard.

However, it is possible to find values in the document "Valeurs tabulées des caractéristiques des parois vitrées et des correctifs associés aux baies" from CSTB.

Thus, by default:

  • for double glazing without sun protection: TLw=0.5, TLw_dif=0
  • for double glazing with opaque and dark sun protection on the outside: TLsw=0, TLsw_dif=0
  • for double glazing with non-opaque and clear sun protection on the outside: TLsw=0.09, TLsw_dif=0.03

The output vector corresponds to the set of 4 minimum light transmittance values to compute transmitted illuminance. It corresponds to: Tli_sp, Tlid_sp, Tli_ap and Tlid_ap, used in direct, diffuse and reflected transmitted illuminance equations in the computation method Th-BCE 2012.

Bibliography

Règles Th-L - Caractérisation du facteur de transmission lumineuse des parois du bâtiment - CSTB March 2012.

Valeurs tabulées des parois vitrées - CSTB March 2012.

Instructions for use

none

Known limits / Use precautions

near shading must be specify ahead because then the consideration of architecture shading is done according to the type of mask.

Validations

Non validated model - Laura Sudries 05/2014

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Licensed by EDF under a 3-clause BSD-license
Copyright © EDF 2009 - 2023
BuildSysPro version 3.6.0
Author : Laura SUDRIES, Vincent MAGNAUDEIX, EDF (2014)
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Parameters

TypeNameDefaultDescription
RealH1Window height
RealL1Window width
Reale0.35Wall thickness
Realazimut0Surface azimuth (Orientation relative to the south) - S=0°, E=-90°, W=90°, N=180°
RealTLw0.5Global light transmittance without solar shading
RealTLw_dif0Diffuse light transmittance without solar shading
RealTLws0Global light transmittance with solar shading
RealTLws_dif0Diffuse light transmittance with solar shading
BooleanMasqueProchefalse
BooleanProtectionfalse

Connectors

TypeNameDefaultDescription
Modelica.Blocks.Interfaces.RealOutput[4]CoeffTransLumLight transmittance -global without protection,- diffuse without protection, - global with protection, -diffuse with protection