Simple Solar Study

An indoor/outdoor daylighting analysis plugin for Trimble SketchUp®

Usage

  1. Geo-reference the model (one time)
    2. This establishes the latitude and longitude with which to calculate the sun’’s position. Geo-referencing also identifies the north direction (generally along the green axis).
  2. Create a Group consisting of faces to be analyzed (one time)
    3. SimpleSolarStudy does not require the faces to be contiguous, but they do need to be grouped together. Faces can be grouped using the Edit | Make Group menu or the context-sensitive right-click menu. If the target surface is to be tilted (advanced mode only), the faces within the group should be tilted rather than tilting the group as a whole.
  3. Select the Group of faces to analyze
  4. Run SimpleSolarStudy from SketchUp’’s "Plugins" menu. There are two modes: basic and advanced.

Basic mode

Layer with shade structures

Select the layer that contains faces that might cast shadows on the target surface. Note: the number of faces exponentially increases computation time, so some care should be taken to isolate faces that will actually block the sun.

Time zone

Relative to Greenwich Mean Time or Universal Coordinated Time, so -5 is Eastern Standard Time in the United States, +3 is Kenyan Time and +9 is Japan Standard Time. Daylight savings time is ignored.

Start month/day and End month/day

The time period for analysis. Dates are inclusive, so specifying a start date of March 3 and end date of March 3 will result in one day of calculations.

Year

The plugin only supports a time period that begins and ends in the same calendar year.

Calculation mode:
Coarse

The plugin will count the number of hours of available daylight (sunrise to sunset) and the number of hours daylight hits each face. The daylight factor for each face is expressed as a ratio of those two numbers. Tilting the target face has no effect.

Medium

Same as "“Coarse", but the closer the sun to the horizon, the less effect it has. Tilting the target face has no effect.

Fine

This mode uses the Bird-Hulstrum clear sky model (1981) to calculate direct and diffuse sunlight on the target faces. The model takes into account such things as forward scattering of light through the atmosphere and reflectivity from the ground. The direct light component is adjusted for tilted target surfaces. Since the denominator in the daylight factor calculation is based on light striking a horizontal surface, a surface tilted toward the sun can result in a daylight factor greater than 1.00.

TMY3

This mode reads in a weather file in TMY3 (typical meterological year) format to account for average cloud conditions. Maximum sunlight to calculate daylight factor is determined using the Bird-Hulstrum clear sky model for a horizontal surface.

Label results

If yes, each face is labeled with its calculated daylight factor.

Gradient

A color is applied to each face based on its daylight factor.


Advanced mode

Layer(s) with shade structures

A comma-separated list of layer names (case-sensitive).

Layer(s) of glazing [OPTIONAL]

A comma-separated list of layers names (case-sensitive) containing transmissive materials.

Glazing transmittance [values 0-100]

A comma-separated list of visible transmittance corresponding to the above glazing layers. A value of 0 means no light passes through. If a single transmittance number is used, it will be applied to all glazing layers.

Trace sun path?

Draw edges between sun positions from sunrise to sunset on the first day of the month from January through June.

Result units

Output results in terms of daylight factor or in watts per meter squared (only meaningful if the Calculation mode is set to "“Fine"”).

Save results to file?

Save the daylight factor of each face to a comma-separated file.

Advanced parameters

Parameter/value pairs are separated by commas (spaces are ignored):

parameter1=value1, parameter2=value2, ....

Additional details in PDF documentation