SunExposure extension calculates number of hours during a time period
when direct sunlight hits SketchUp model's surfaces.
SunExposure extension is oriented towards early project design phases, when level of details of future building is rather low, and when only basic information about building environment, position and geometry are defined.
Information about exposure to the direct sun can influence on important decisions related to building lighting and thermal strategies:
Sun exposure of a point on the facade depends on building site weather and environment (relief, obstruction buildings), selected time period and also on building shape, facades orientation and sun protections. It is independent on materials used on facades or environment and on building interior.
Open SketchUp model. Follow next instructions to prepare your model for DL-Light calculations.
Open SunExposure dialog from toolbar or menu Extensions -> De Luminae -> SunExposure -> SunExposure calculation and enter the parameters of the calculation.
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 'sunexposure_output'
For SketchUp projects on a remote computer, read details in Remote files .
Analysis - Results represented by false color textures can have different meaning depending on selected value:
Details - Models may require different density of sensors. Level of details definition is directly connected to number of sensors or their density on surfaces. Big unobstructed surfaces may need lower levelof details, with few sensors only, while smaller surfaces or surfaces with complex obstructions may require very high level of details. Level of details determines number of sensors for calculation, and has a major influence on calculation time and results accuracy.
DL-Light allows to choose:
See sensors selection for more information on the choices of proposed sensors.
Location - Building location coordinates. This info is used in combination with weather data to generate correct sky distribution. Location can be based on SketchUp model location, current Weather file location or be Custom. Below is dialog for Custom location definition.
The chosen weather file defines the time zone used for dates and times of calculations. For clear sky mode, the time zone can be defined below.
Time zone - Display of the time zone used for the calculations.
The time zone is defined by the selected climate data file.
For clear sky mode, a list of selection allows you to choose
the time zone. In clear sky mode, if the "SketchUp location"
is chosen, the time zone set in SketchUp is used. However, if
a weather file is already chosen and its time zone is
different, a warning is displayed.
Note: when a model is located in SketchUp, SketchUp proposes a time zone based on the longitude of the place. This value is sometimes wrong, especially for European or Asian countries.
Period - The analysis period, defined by a season, the entire year, or two specific dates:
Default seasons are defined for northern hemisphere. Advanced parameters allow to use different definition of seasons. Read details.
Full days - occupancy range from 0h00 to 23h59 on the day range (end date included). Click on the input box and choose the date in the calendar, or enter it directly.
Hours per day - occupancy range in hours on the range of days (end date included).
Start / end - interval between start date and end date.
Complex - use a complex definition of period. See complex period configuration.
In trial version of the extension only 'summer' and 'winter' periods are supported. For more details read License information.
Time step - In clear sky mode only, time step in minutes for the simulation.
(If a weather file is used, the time step is set to 60 minutes.)
Palette of false colours can be defined with precision. 3 options for palette are given, Automatic, Gradient and Custom:
After entering the parameters, select one or few surfaces and press Render or button.
Calculation time depends on number of selected surfaces, level of sensors details and model's complexity.
When results are imported, selected surface will have appropriate false colors and Palette and Report dalogs will be opened.
Report dialog - shows distribution of results over current palette and calculation input parameters.
Show/Hide Sensors and Values - explore irradiance results directly in the model for each sensor.
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 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":
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 to use exactly the same model as when calculating.
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.
Current SketchUp model view with imported results can be exported
or without palette
png format. Open the folder of images with .
This option is not supported in trial version of the extension (see licence information).
This feature is not supported in trial version (see licence 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 simulations 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).
On 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 yet benefit from the cache system.