What do I need to run the program?
Any web browser, plus the Adobe Flash plug-in. Flash is available from adobe.com.
What if I want to set the clock to 24-hour time?
Click the "12-hr" text in the lower-right corner. Please see the instructions for details.
How accurate is the program?
The inputs are accurate to two decimal places, since fractional degrees, etc. don't substantially impact the results. The calculations themselves are quite accurate, although further tests will be done as time allows to assure that they're consistent with other sources. Since the program was designed for solar energy analysis, extremely high accuracy was not a goal.
What is your source for these calculations?
The basic solar angle calculations are from a variety of sources, and I would suggest looking in the ASHRAE 1993 Fundamentals volume for more information. The shading projections were derived by susdesign.com using basic trigonometry functions.
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.
