Ecotect

I had a meeting today with Thida about the Ecotect results. Here is what we concluded - mostly through trial and error:

Ecotect is good for Sunpath diagrams, Insolation calculations (under Solar Access menu), and Solar Exposure, all on individual surfaces. Insolation calculations on grid points are OK, but they are different from surfaces.

• For a surface, the radiation can only hit it from one side. In addition, the angle of incidence makes a difference - radiation at right angles to the surface has a bigger effect that radiation coming in at an acute angle.
• For a grid, the point is idealized like a small ball. The radiation can come from all directions - so the values can be much higher. Also, the angle of incidence makes no difference.

For Lighting Analysis - light levels (lux) and daylight factors (%), Ecotect is quite inaccurate. Therefore, it is better to use Ecotect together with Radiance. Radiance can be downloaded and installed for free . You can do either grids or images.

• For Ecotect/Radiance grids: You set up the model and the grid in Ecotect, and then use Ecotect to run the Radiance calc, and then import the results back into Ecotect to display the results.
• For Ecotect/Radiance images: You set up the model and the camera in Ecotect, and then use Ecotect to run the Radiance calc. The image will be displayed in a special Ecotect window, where you can do various things, like false colour images etc.

So, first you need to install Radiance. This is straightforward -

• Download the software
  http://floyd.lbl.gov/misc/download20B.html
• Unzip it to a temporary location
• Run setup.exe
• Click 'Next' until you get to 'Setup type', choose 'Radiance for Windows'
• When you get to 'Choose Radiance for Windows Installation Location', the default location is fine. Or you may want to put it on D if you do not have permission for C. However, make sure your path has no spaces.
• Then click 'Next' all the way to the end.
• If you get an error about a folder icon, ignore it.

To run and Ecotect/Radiance analysis:

• Set up your model in Ecotect
• Set up the grid in Ecotect
• In the menu, go to Calculate > Lighting Analysis
• Select Export to Radiance, and click Next

Here are the steps to follow from here on if you want to do a grid analysis:

1. Choose 'Daylight Factors' (for example)
   
2. Choose 'Surface and/or point analysis'
   
3. Choose 'Analysis Grid' - and if you want you can also choose the 3D option
   
4. Choose 'Interior Views'
   
5. De-select 'Current 3d Editor view' and make sure that nothing else is selected
6. For accuracy, 'Medium' is fine
7. For the output and installation, first click the Fix button and find the file Rad.exe (in ...Radiance\bin\) - which is teh RAdiance program; the n tell Ecotect where to save the ARdiance files - choose a path with no spaces.
8. Accept the advanced rendering settings as they are - click next
9. Finally, you are ready to run radiance - click OK

A black command window will pop up, and some calculations will start. When the calculations are complete, Ecotect will pop up a RadianceImport dialog box - which is asking you if you want to import the results. So click 'Import'. In the Analysis Grid panel, under Data & Scale, you will see RAD Daylight Factors. This will display the results from the Radiance calculation.