.BuildSysPro.Building.BuildingEnvelope.HeatTransfer.SimpleWindow

Information

Simple linear model of glazing

Hypothesis and equations

This is a model of a simple window. Incident flows with short wavelength (SWR) are global surface flows. The influence of the angle of incidence on the direct flows transmission (non-linear) is outsourced and therefore not described in this model.

Long wavelength (LW) exchanges are linearized with the model LinearExtLWR. The parameter skyViewFactor determines the share of long wavelength radiation of the wall with the sky, considered at T_sky, and the external environment, considered at T_ext.

The coefficient k represents the glazing conductivity without considering convective exchanges (different from Ug or Uw usually used). The coefficient of convective heat transfer with the outside hs_ext default value is the value of the coefficient integrating convection only. LWR exchanges are considered elsewhere.

This model leads to a linear time-invariant model that can be reduced.

Regarding the rolling shutters, the assumptions are:

• No solar flux transmitted by the part obscured by the shutters
• Absorbed flux unchanged (PVC absorbency similar to that of glass)
• If the shutter is not completely closed (Coeff_Fermeture <95%), unchanged thermal resistance
• If the shutter is fully closed, increased thermal resistance of an additional thermal resistance, evaluated at 0.2 m²K / W (PVC thickness of 12 mm approx.)

Bibliography

Window model modified in order to obtain a linear time-invariant model for the purposes of cities study.

CSTB. 2005. Guide réglementaire RT 2005. Règle d'application Th-Bât Th-U 3/5 Parois vitrées.

Instructions for use

The thermal ports T_ext and T_int must be connected to temperature nodes (connect T_ext to T_dry of Meteofile). The external incident flows FluxIncExt and FluxTr come from the solar boundary conditions model SolarBC. The correspondence between their settings must be made.

Known limits / Use precautions

The limitations are mainly related to the LWR flows linearization and to the outsourcing of the influence of the impact on SWR transmitted fluxes.

Validations

Validated model - Gilles Plessis 03/2013

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Licensed by EDF under a 3-clause BSD-license
Copyright © EDF 2009 - 2023
BuildSysPro version 3.6.0
Author : Gilles PLESSIS, EDF (2013)
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Revisions

Amy Lindsay 03/2014 : ajout de la possibilité de commander un volet (fermeture_volet qui varie entre 0 et 1 - 1 quand le volet est fermé, 0 quand le volet est ouvert), avec la résistance thermique supplémentaire que cela engendre.

Gilles Plessis 07/2015 : ajout de la possibilité optionnelle de prise en compte du rayonnement GLO linéarisé.

Benoît Charrier 02/2017 : deleting useless application of solar transmission coefficient because of transmitted solar radiation in input.