Designing with daylight in mind not only allows for a more comfortable interior space, but it can also give you substantial savings in energy consumption.
We’d like to thank our colleague, architect Angelo Dugnani, for this tip.
Calculating the daylight factor in buildings is generally required by local regulations for a variety of building uses, including but not limited to residential and commercial.
When designing with ArchiCAD, integrating a daylight simulation and the daylight factor calculation via VELUX Daylight Visualizer is simple and quick, here’s how:
1. make testing model
In ArchiCAD 15, we created a testing model, made up by simple four walls, a floor, a ceiling, and four windows:
The plan view of the testing model in ArchiCAD 15.
3D view of the testing model in ArchiCAD 15.
2. export from ArchiCAD
In the 3D window of ArchiCAD, we select “save as” and select .obj file format, which best allows us to export the testing model with the assigned materials (we also tested exporting in .dxf and .skp formats: they both work, with slightly different results).
Exporting the testing model in .obj format from the 3D window of ArchiCAD 15.
3.import to Daylight Visualizer
Once you export the testing model, you need to import it into the Daylight Visualizer:
Velux Daylight Visualizer also allows you to create custom models from within the program. However, in our opinion the possibility to import the 3D model directly from Archicad is so simple and fast, that it does not make sense to create the same BIM model twice.
The testing model created in Archicad 15, as seen in the Daylight Visualizer once the import operation is complete.
4. assign materials
At this point, you’ll need to assign the materials from the Daylight Visualizer archive to the ones assigned to the testing model in Archicad. It is of critical importance to assign the correct light transmission value to the glass panes:
The “translation” or the Archicad materials to the corresponding Daylight Visualizer ones.
This particular aspect could be improved in the future, allowing for an automatic association of the source materials while importing the model. This could be done with a simple translator.
5. adjust settings and simulate
The location menu allows to choose the geographical location of the simulation, as well as the orientation:
Site and orientation selection in Daylight Visualizer.
In the camera menu, you can select whether to simulate in plan view, section, or perspective. You can also enter the elevation of the cutting plane:
Setting up the camera before proceeding with the rendering.
Last, the render menu allows you to select among standard CIE sky conditions, the kind of output you want (static or dynamic), the time lapse to be simulated, as well as the resolution of the output itself.
Selecting different kinds of output in the render menu.
Velux Daylight Visualizer allows you to simulate:
- daylight factor.
The standard sky condition models are determined by the CIE.
Rendering settings allow to generate ISO contour lines.
The output of the simulation calculated with Daylight Visualizer can be exported as .png image.
Once you learn the fundamental steps of the process, it takes only a few minutes to export your BIM model from Archicad and import it into the Velux Daylight Visualizer.
We have not yet had the chance to test the Daylight Visualizer with more complex models, and we are planning to do it in the near future.