modelExteriorHeatTransfer

Model for heat convection and radiation at the exterior surface of a window that may have a shading device

Extends from BaseClasses.PartialWindowBoundaryCondition (Partial model for heat convection or radiation between a possibly shaded window that can be outside or inside the room).

Information

Model for the convective heat transfer between a window shade, a window surface and the room air. This model is applicable for the outside-facing surface of a window system and can be used with the model Buildings.HeatTransfer.Windows.Window.

This model adds the convective heat transfer coefficient to its base model.

Parameters

TypeNameDefaultDescription
Modelica.Units.SI.AreaA (from PartialWindowBoundaryCondition)Heat transfer area of frame and window
RealfFra (from PartialWindowBoundaryCondition)Fraction of window frame divided by total window area
Modelica.Units.SI.AreaAFra (from PartialWindowBoundaryCondition)fFra*AFrame area
Modelica.Units.SI.AreaAGla (from PartialWindowBoundaryCondition)A - AFraGlass area
BooleanlinearizeRadiationSet to true to linearize emissive power
RealvieFacSkyView factor from receiving surface to sky
Shading
BooleanhaveExteriorShade (from PartialWindowBoundaryCondition)Set to true if window has exterior shade (at surface a)
BooleanhaveInteriorShade (from PartialWindowBoundaryCondition)Set to true if window has interior shade (at surface b)
BooleanhaveShade (from PartialWindowBoundaryCondition)haveExteriorShade or haveInteriorShadeSet to true if window system has a shade
BooleanthisSideHasShade (from PartialWindowBoundaryCondition)Set to true if this side of the model has a shade
Modelica.Units.SI.EmissivityabsIRSha_airInfrared absorptivity of shade surface that faces air
Modelica.Units.SI.EmissivityabsIRSha_glassInfrared absorptivity of shade surface that faces glass
Modelica.Units.SI.TransmissionCoefficienttauIRSha_airInfrared transmissivity of shade for radiation coming from the exterior or the room
Modelica.Units.SI.TransmissionCoefficienttauIRSha_glassInfrared transmissivity of shade for radiation coming from the glass

Connectors

TypeNameDefaultDescription
Modelica.Blocks.Interfaces.RealInputuSha (from PartialWindowBoundaryCondition)Input connector, used to scale the surface area to take into account an operable shading device, 0: unshaded; 1: fully shaded
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_aair (from PartialWindowBoundaryCondition)Port that connects to the air (room or outside)
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_bglaUns (from PartialWindowBoundaryCondition)Heat port that connects to unshaded part of glass
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_bglaSha (from PartialWindowBoundaryCondition)Heat port that connects to shaded part of glass
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_aframe (from PartialWindowBoundaryCondition)Heat port at window frame
Modelica.Blocks.Interfaces.RealInputvWinWind speed
Modelica.Blocks.Interfaces.RealInputTBlaSkyBlack body sky temperature
Modelica.Blocks.Interfaces.RealInputTOutOutside temperature
Interfaces.RadiosityOutflowJOutUnsOutgoing radiosity that connects to unshaded part of glass
Interfaces.RadiosityInflowJInUnsIncoming radiosity that connects to unshaded part of glass
Interfaces.RadiosityOutflowJOutShaOutgoing radiosity that connects to shaded part of glass
Interfaces.RadiosityInflowJInShaIncoming radiosity that connects to shaded part of glass
Modelica.Blocks.Interfaces.RealInputQSolAbs_flowSolar radiation absorbed by shade

Components

TypeNameDefaultDescription
Buildings.HeatTransfer.Windows.BaseClasses.ExteriorConvectionCoefficientconCoeGlaModel for the outside convective heat transfer coefficient of the glass
Buildings.HeatTransfer.Windows.BaseClasses.ExteriorConvectionCoefficientconCoeFraModel for the outside convective heat transfer coefficient of the frame
Radiosity.OutdoorRadiosityradOutOutdoor radiosity
BaseClasses.ShadeRadiationshaRadRadiative heat balance of shade
Modelica.Thermal.HeatTransfer.Components.ConvectionconFraConvective heat transfer between air and frame
Modelica.Thermal.HeatTransfer.Components.ConvectionconWinUnsConvection from unshaded part of window to outside or room air

Revisions

  • March 2, 2015, by Michael Wetter:
    Refactored model to allow a temperature dependent convective heat transfer on the room side. This is for issue 52.
  • February 8 2012, by Michael Wetter:
    Changed model to use new implementation of Buildings.HeatTransfer.Radiosity.OutdoorRadiosity. This change leads to the use of the same equations for the radiative heat transfer between window and ambient as is used for the opaque constructions.
  • October 25 2010, by Michael Wetter:
    First implementation.