Comparative prediction of apparent cartesian and polar sun charts for Riyadh, Kingdom of Saudi Arabia

الملخص EN

-The availability of the yearly/monthly average sun charts is a very useful piece of information for architectural engineers and researchers in passive building design and shading of solar applications.

Usually, trigonometric relationships are used to calculate the solar angles needed to draw the apparent sun charts.

Also, available software programs can be used to directly draw these charts in a very short time.

These programs were developed by recognized solar research institutions.

These programs are available free from common-knowledge domain on the web.

However, no previous work was done to check their accuracy and validity.

A comparative study indicated that the available software programs are as good as direct calculations obtained from trigonometric relationships.

This study was conducted for the city of Riyadh, Kingdom of Saudi Arabia.

The calculations indicated that the deviation in results between trigonometric relationships and the available programs was within ±1 %.