SunExposure Extension

Introduction

SunExposure extension calculates the number of hours over a time period when direct sunlight hits SketchUp model surfaces.
SunExposure extension is oriented towards early project design phases. Level of details of future building can be rather low, and only basic information about building environment, position and geometry are needed.

This extension also provides:

DL-Light extension sketchup sunexposure SketchUp model snapshot
        image

Information about exposure to the direct sun can influence important decisions related to building lighting and thermal strategies:

Sun exposure of a point on the facade depends on site climate and environment (relief, obstruction buildings), selected time period and on building shape, facades orientation and sun protections. It is independent on materials used and on building interior.


How to use SunExposure Extension

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

  2. Open SunExposure dialog from toolbar se_dialog_icon or menu Extensions -> De Luminae -> SunExposure -> SunExposure calculation and enter calculation parameters.

    DL-Light extension sketchup sunexposure General tab

    Fields description:

  3. Palette of false colours can be defined with precision. 3 options for palette are given, Automatic, Gradient and Custom:

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

    DL-Light extension sketchup sunexposure SketchUp selection

    Calculation time depends on the number of selected surfaces, the level of sensors details and model complexity.

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

    DL-Light extension sketchup sunexposure SketchUp result imported -
            automatic palette
  6. Results analysis.

  7. For further calculations on 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 if a calculation has just been made for the "summer" season, then the season is changed to "winter" for a recalculation, and finally recalculated for "summer":

  8. Archiving results:

    DL-Light allows to archive all the results of a calculation: reports, textures and calculation steps (exported Radiance model, weather file, ...). 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 license information).

    DL-Light extension sketchup sunexposure SketchUp model snapshot image

Additional reports: exposure per day and hours

This feature is not supported in trial version (see license information).

When calculating Sun Exposure, it is possible to generate for each surface two additional reports in CSV format:


To generate these reports, validate the option "Additional reports: exposure per day and hours" in the preferences of the extension. The reports are saved in the sunexposure_output/current/reports subdirectory


Shadow calculation

This feature is not supported in trial version (see license information).

Shadow calculation is the opposite of the sun exposure calculation: the indicator shows the duration during which the direct sunlight did not reach the surface.

screenshot daylight exposure shadows

Calculation for single time moment

This feature is not supported in trial version (see license information).

Calculation for a specific time moment measures areas in the sun and in the shade at a specific time for a clear sky. For this feature a Radiance simulation is performed for the entire surface. This function does not use point sensors on the surface, the value chosen for the level of detail of the sensors is not taken into account.

False color palette is automatically adapted and contains only 2 values: "no light" (blue) and "light" (yellow).

DL-Light extension sketchup sunexposure single hour

On the image above sun exposure results (left) are compared to shadow results from SketchUp (right), for the same location and time moment.
Shadow patterns from SketchUp and SunExposure match when hour format is set to 'standard'. When hours format is set to 'solar' sun position is calculated as for solar hour, and shadows positions don't match. Read more on page Standard versus solar time calculation.

Limitation: The calculation for a specific time moment does not benefit from the cache system.