modelOverhang
Extends from Buildings.ThermalZones.Detailed.BaseClasses.Overhang (Record for window overhang), Buildings.HeatTransfer.Windows.BaseClasses.PartialShade_weatherBus (Partial model to implement overhang and side fins with weather bus connector).
Information
For a window with an overhang, this model outputs the fraction of the area that is exposed to the sun. The models can also be used for doors with an overhang.
The overhang can be asymmetrical (i.e. wR ≠ wL is allowed)
about the vertical centerline of the window. However, the
overhang must completely cover the window,
i.e., wL ≥ 0 and wR ≥ 0.
wL and wR must be measured from the respective corner
of the window.
The figure below shows the parameters.
The surface azimuth azi is as defined in
Buildings.Types.Azimuth.
Limitations
The model assumes that
- the overhang is at least as wide as the window, i.e., wL ≥ 0 and wR ≥ 0, and
- the overhang is horizontal.
Implementation
The implementation is explained in Buildings.HeatTransfer.Windows.BaseClasses.Overhang.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | haveOverhang (from Overhang) | dep > Modelica.Constants.eps | Flag, true if the window has an overhang |
| Modelica.Units.SI.Angle | azi | Surface azimuth; azi= -90 degree East; azi= 0 South | |
| General › Overhang | |||
| Modelica.Units.SI.Length | wL (from Overhang) | Overhang width left to the window, measured from the window corner | |
| Modelica.Units.SI.Length | wR (from Overhang) | Overhang width right to the window, measured from the window corner | |
| Modelica.Units.SI.Length | dep (from Overhang) | Overhang depth (measured perpendicular to the wall plane) | |
| Modelica.Units.SI.Length | gap (from Overhang) | Distance between window upper edge and overhang lower edge | |
| General › Window | |||
| Modelica.Units.SI.Length | hWin (from PartialShade_weatherBus) | Window height | |
| Modelica.Units.SI.Length | wWin (from PartialShade_weatherBus) | Window width | |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.BoundaryConditions.WeatherData.Bus | weaBus (from ShadeInterface_weatherBus) | Weather data bus | |
| Modelica.Blocks.Interfaces.RealInput | incAng (from ShadeInterface_weatherBus) | Solar incidence angle | |
| Modelica.Blocks.Interfaces.RealInput | HDirTilUns (from ShadeInterface_weatherBus) | Direct solar irradiation on tilted, unshaded surface | |
| Modelica.Blocks.Interfaces.RealOutput | HDirTil (from ShadeInterface_weatherBus) | Direct solar irradiation on tilted, shaded surface | |
| Modelica.Blocks.Interfaces.RealOutput | fraSun (from ShadeInterface_weatherBus) | Fraction of the area that is unshaded |
Revisions
-
September 16, 2021, by Michael Wetter:
Removed parameterlatbecause the latitude is now obtained from the weather data bus.
This is for IBPSA, #1477. -
July 5, 2012, by Michael Wetter:
Changed definitions ofwLandwRto be measured from the corner of the window instead of the centerline. This allows changing the window width without having to adjust the overhang parameters. -
February 25, 2012, by Michael Wetter:
Revised implementation. -
Feb 01, 2012, by Kaustubh Phalak
First implementation.