FAQS LOUVRE SHADING CALCULATOR

What if my louvres aren't rectangular in cross-section?

This tool assumes they are, so you'll just have to come up with a rectangular approximation. You won't be far off unless your louvres have a very strange shape. In that case, please contact us for assistance.

Does the tool take into account sunlight reflected by the louvres?

No. It assumes that sunlight incident on the louvres produces shade. So if you have highly reflective louvre surfaces, you may realise less shade than is suggested by the outputs of this tool.

What's the difference between white and yellow cells in the outputs?

A blank white cell indicates that the sun is below the horizon at that time. A yellow cell indicates that the sun is above the horizon, but not shining on the wall or window (for example, if a horizontal overhead louvre is designed to shade a south-facing wall at a temperate latitude, in the early morning or late evening in the summertime, the sun will be north of the wall, so not shining on it).

How accurate is the program?

The shading calculations are very accurate, but the precision of the tool is 10% since the dates and times are considered broadly.

Can I copy and paste the data into another application?

Yes. Set the "show values" input to "Sun %" or "Shade %", and click "Calculate". Then use your mouse to select the table data, and copy paste it into Microsoft Excel or another program. In Excel, the rows and columns of the data should be preserved.

May I use your calculations?

The program and its design are copyrighted. If you wish to use the calculations in the source code, please feel free to do for non-commercial applications and please notify us.

What is your source for these calculations?

The basic solar angle calculations are from a variety of sources, and we would suggest looking in the ASHRAE 1993 Fundamentals volume for more information. The shading projections were derived by susdesign.com using basic trigonometry relations.

Can you write a custom program for me?

If you can't find the calculations relevant to your project, please contact us to receive shading information specifically for your project.