BuildSysPro.Building.BuildingEnvelope.Functions.CalculAlphaTauDoubleGlazing

# .BuildSysPro.Building.BuildingEnvelope.Functions.CalculAlphaTauDoubleGlazing

Calculation of absorption and transmission coefficients of a double glazing window

## Information

Hypothesis and equations

This function calculates the absorption and transmission coefficients of a double glazing window, for direct and diffuse solar fluxes, from manufacturer data :

- Uw : Heat transfert coefficient of the window [W/m².K]
- g : Solar factor of the glazing [between 0 and 1]
- tau0 : Coefficient of energy transmission of the glazing [between 0 and 1]

Bibliography

Standard EN 410 for calculation of equivalent coefficients for direct solar flux on normal incidence.

Method Th-S from RT for calculation of equivalent coefficients for diffuse solar flux.

Instructions for use

none

Known limits / Use precautions

none

Validations

Validated model - Benoît Charrier 02/2016

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Licensed by EDF under a 3-clause BSD-license
Copyright © EDF 2009 - 2023
BuildSysPro version 3.6.0
Author : Benoît CHARRIER, EDF (2016)
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#### Interface

>     function CalculAlphaTauDoubleGlazing
>       input Modelica.Units.SI.CoefficientOfHeatTransfer Uw "Heat transfert coefficient of the window";
>       input Real g "Solar factor of the window [between 0 and 1]";
>       input Real tau0 "Coefficient of energy transmission [between 0 and 1]";
>       input Modelica.Units.SI.CoefficientOfHeatTransfer Hext = 21 "Global surface exchange coefficient on the outer face of the window";
>       input Modelica.Units.SI.CoefficientOfHeatTransfer Hint = 8.29 "Global surface exchange coefficient on the inner face of the window";
>       output Real alpha_dir "Direct absorption coefficient of the window";
>       output Real alpha_dif "Diffuse absorption coefficient of the window";
>       output Real tau_dir "Direct transmission coefficient of the window";
>       output Real tau_dif "Diffuse transmission coefficient of the window";
>     end CalculAlphaTauDoubleGlazing;

## Revisions

Benoît Charrier 08/2017 : correction of errors in documentation and parameter naming, manufacturer data needed are the coefficient of energy transmission of the glazing (tau0) and the solar factor of the glazing (g).

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