Horizontal Sight Angle Extension

Introduction

The Horizontal Sight Angle is the measurement at a point of the viewing angle towards the outside. The openings are the windows looking towards the exterior of the building. The horizontal sight angle of a room completely closed is 0°, the horizontal sight angle of a flat surface without any wall around is 360°.

DL-Light extension No-sky Line

The Horizontal Sight Angle indicator is used in particular by the European standard EN 17037 (in UK: BS EN 17037:2018 Daylight in buildings).

The EN 17037 standard uses 3 thresholds for the sight angle: 14°, 28° and 54°. This extension makes it possible to analyze a surface according to a customizable scale that can give more information during the design phase than these 3 thresholds.

According to standard EN 17037 the measurements can be carried out at a height of 1.2m or 1.7m from the floor. The distance of 1.2m is the default setting of the virtual surfaces for this extension (value configurable in the preferences). For the use of virtual surfaces, see page: Create virtual surfaces.


How to use Horizontal Sight Angle Extension

Important: layers corresponding to glazing must be hidden.

  1. Open SketchUp model. Follow recommendations to prepare your model for DL-Light calculations.

  2. Open Horizontal Sight Angle dialog from toolbar sa_icon_24 or menu Extensions -> De Luminae -> Horizontal Sight Angle -> Horizontal Sight Angle computation and enter the parameters of the calculation.

    DL-Light extension Horizontal Sight Angle General tab

    Fields description:

  3. The default color palette is a non-linear scale:

    DL-Light extension Horizontal Sight Angle Panel tab

    To obtain a grid with only the EN 17037 thresholds, just create a custom palette by removing the intermediate thresholds: click on a level to remove, then on the "minus" button.

    DL-Light extension Horizontal Sight Angle Panel tab
  4. After entering the parameters, select surfaces and press Render or run_selected button.

    DL-Light extension Horizontal Sight Angle selection

    Calculation time depends on number of selected surfaces and model complexity.

  5. When results are imported, selected surface will have appropriate false colors and Palette and Report dialogs will be opened.

    DL-Light extension Horizontal Sight Angle result 1
  6. Results analysis.

  7. For further calculations in the same model:

    Since version 8.0, DL-Light uses a calculation cache algorithm. It automatically detects if a surface requires recalculation or if a previous result can be reused. By default, the cache keeps the information of the last 10 calculations (value configurable in the preferences).

    For example, restarting calculation with another palette is fast, here with the thresholds of standard EN 17037:

    DL-Light extension Horizontal Sight Angle result 2
  8. Archiving results:

    DL-Light allows to archive all the results of a calculation: reports, textures and calculation steps (exported Radiance model ...). This archive can be reloaded on the model, subject to using exactly the same model as during the calculation.

    See the page Archiving results for more informations about this feature.

    See the page Comparison of results for more informations about comparison of several archives.

  9. Snapshots:

    Current SketchUp model view with imported results can be exported with palette snapshot_with_palette_icon or without palette snapshot_icon to png format. Open the folder of images with open_snapshot_folder_icon.
    This option is not supported in trial version of the extension (see licence information).

    DL-Light extension Horizontal Sight Angles snapshot image