Ecotect provides a number of different methodologies for calculating the daylight factor of a given space. This tutorial demonstrates how to perform and display a daylight factor calculation using points.
You will need about 20 minutes to complete this tutorial.
Training and Accreditation
Successfully completing this tutorial fulfills one of the practical skills required for completing Level 1 of the Daylight training module.
To complete this tutorial, download the DaylightExample.zip Ecotect file available in the File Attachments section of this tutorial.
- Now we can perform the daylight factor calculation. Go to the Calculate...' menu and select the Lighting Analysis item.
Select the Lighting Analysis item from the Calculate menu.
- The Lighting Analysis Wizard dialogue box appears on screen. As we haven't put any artificial lighting in our model, select the Natural Light Levels radio option and then click Next.
Select Natural Light Levels and click Next.
- The wizard now prompts you to specify where light values should be calculated. As we are doing a point analysis, select At Specific Points in the Model and click Next. The Selected Points Only checkbox option allows you to specify particular points to analyze.
Select At Specific Points in the Model and click Next.
- Now set the precision level for your daylight factor calculation. Naturally, the more precise the calculation, the longer Ecotect takes to complete the analysis. Click Next once you're done.
Set the precision level for the calculation.
- Set the Design Sky and Luminance Distribution for the calculation. Because you specified the geographic location at the beginning of the tutorial, the Design Sky should already be set. As for Luminance Distribution, this is generally left on Overcast Sky Condition, unless you have reason to believe Uniform Sky Condition is more appropriate (ie. for location near the equator). Click Next.
Set the Design Sky and Luminance Distribution.
- Now we specify the room-based settings. Select Average (x 0.90) window cleanliness, and check Calculate Room-Averaged Window Areas. Click Next.
Specify the room-based settings.
- We're almost there. The wizard will now display a summary of the settings you have selected. Make any adjustments if required, and then click Ok.
The wizard summarizes your calculation settings.
- Just before Ecotect starts the daylight factor calculation process, a dialogue box will prompt you to recalculate the inter-zonal adjacencies in your model. It's generally a good practice to do this, so click Ok.
Click Ok to recalculate interzonal adjacancies.
- Ecotect starts performing its calculations, and then displays the daylight factor values for the points you created. A legend appears in the top right hand side of the main work area showing the range of values calculated.
Ecotect calculates the daylight factor points and displays them accordingly.
- Nice work - you have just used Ecotect to calculate daylight factors for a zone using points. The next tutorial will look at calculating daylight factors using the analysis grid.
- To change the attribute/units being measured, go to the Display>Object Attribute Values and then select from one of the first three menu options - Daylight Factor,Daylight levels or Sky Component.
- Remember than sunlight and daylight are not one and the same thing - building orientation does not affect the daylight factor, but does impact on the penetration of sunlight into a building. Refer to Sunlight vs Daylight for more information.
- Even though the three windows have the same surface area, note how the different window proportions impacts on the penetration of daylight into the space.