.Buildings.HeatTransfer.Windows.FixedShade

Information

This model outputs the fraction of the window area that is sun exposed for a window that may have an overhang and sidefins. Depending on the record with construction data conPar, an overhang, side fins or no external shade is modeled. The model allows having an overhang and side fins at the same time. In such a case, the overhang width should be measured from the window edge to the sidefin, because the overhang width beyond the sidefin will cast a shadow on the side fin and not on the window. Similarly, the side fin height should be measured from the upper window edge to the overhang, because the side fin height above the overhang will not cast a shadow on the window. The parameters for the dimensions of the overhang and side fins are as described in the models Buildings.HeatTransfer.Windows.Overhang and Buildings.HeatTransfer.Windows.SideFins.

Limitations

For overhangs, the model assumes that

• the overhang is at least as wide as the window, i.e., w_L ≥ 0 and w_R ≥ 0, and
• the overhang is horizontal.

For side fins, the model assumes that

• the side fins are placed symmetrically to the left and right of the window,
• the top of the side fins must be at an equal or greater height than the window, and
• the side fins extends at least to the lower edge of the window.

Implementation

The detailed calculation method is explained in Buildings.HeatTransfer.Windows.BaseClasses.SideFins and in Buildings.HeatTransfer.Windows.BaseClasses.Overhang.

Revisions

• September 16, 2021, by Michael Wetter:
  Removed parameter lat because the latitude is now obtained from the weather data bus.
  This is for IBPSA, #1477.
• May 30, 2014, by Michael Wetter:
  Removed undesirable annotation Evaluate=true.
• July 7, 2012, by Michael Wetter:
  Renamed model from Shade to FixedShade because shade is already used for window interior and exterior shades.
• July 5, 2012, by Michael Wetter:
  Moved model from package Buildings.ThermalZones.Detailed.BaseClasses to Buildings.HeatTransfer.Windows, because the overhang and side fin models are also in this package.
• May 21, 2012, by Kaustubh Phalak:
  Enabled the model to use overhang and side at the same time.
• March 5, 2012, by Michael Wetter:
  First implementation.