Horizontal Sight Angle (EN 17037) 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°.

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

This extension is designed to follow the recommendations of the standard:

• use of the 3 thresholds defined in the standard: 14° (minimum), 28° (medium) et 54° (high),
• working plane 1.2m above the floor (configurable in the preferences).

How to use Horizontal Sight Angle (EN 17037) 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 or menu Extensions -> De Luminae -> Horizontal Sight Angle (EN 17037) -> Activate extension and enter the parameters of the calculation.

   
   

   Fields description:

   • Project name - Project name is used during export and for output filenames generation. The SketchUp model name is used by default.

   • Results - Directory where model will be exported for calculation. It should be an existing or a new directory where user has appropriate write/read privileges. When calculation is started model geometry and resulting files will be saved in horiz_sight_angle_17037_output subdirectory.
     For SketchUp projects stored on network disk (Windows), see Work on a copy of the model.

   • Mode - Calculation mode selection:

     • Horizontal Sight Angle: the report and false colors texture display the distribution of angle values ​​on the surface.
     • Surface threshold: the report and false colors texture display the threshold reached by a percentage of the surface, 50% by default.

   • Details - By default, Horizontal Sight Angle calculation uses a dedicated grid 'HSA grid' with 25 sensors per square meter. This density allows to have a sufficient resolution to assess the sight angle in a room with standard openings such as Windows.

     DL-Light allows to choose:

     • the sensor grid applicable by default to all calculated surfaces,
     • different sensor grids for some surfaces ("exceptions" button).
     

     See sensors selection for more information on the choices of proposed sensors.

   • Transparency - The calculation requires that landscape and surrounding buildings are invisible or transparent.

     Use the layer visibility feature of SketchUp, or the dedicated layer transparency interface of DL-Light . This interface allows you to define layers:

     • not exported to Radiance (therefore invisible for calculation),
     • but visible (semi-transparent) on the model SketchUp.

     See page Make layers "transparent" for more details.

3. The palette of false colors uses the thresholds of the standard. It is possible to change the different colors.

   

4. After entering the parameters, select surfaces and press Render or button.

   

   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.

   

   Result for the 'Surface threshold' mode:

   

6. Results analysis.

   • The Report dialog displays the distribution of results over current palette and calculation input parameters.

     By default, the values ​​of the columns "minimum", "medium" and "high" are cumulated, these columns display the total percentage of the surface greater than the threshold.

     

     You can adjust the display of the report in the preferences to display in the columns the non-cumulative percentage of the area.

     

     Report for the 'Surface threshold' mode:

     

   • Show/Hide Sensors and Values explores results directly in the model for each sensor.

     • Nota: the option "View / Guides" of SketchUp must be activated.
     

7. For further calculations in the same model:

   • To run calculation on any surface simply select it and Render .
   • It is possible to modify the parameters of the calculation. Whatever the change, use the Render button. Previously calculated surfaces will be updated with the new settings.

   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).

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.

   • To archive the calculation results, click on the button Save archive.
   • To load the results of a previous calculation, click on the button Load archive

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

9. Snapshots:

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