The sun is 93 million miles away from earth and the solar radiation reaching the earth’s atmosphere remains relatively constant throughout the year at 1367 W/m2 (433 Btu/ft2). However, the length of the atmosphere the sun rays travel, the cloud cover, and atmospheric turbidity has a significant impact on the amount of direct and diffuse solar radiation reaching to earth’s surface (Stein et al., 2006). The orientation and the slope of a surface, the neighboring structures that block and/or reflect solar rays will further impact the amount of radiation received on a given surface.
The key to successful daylighting design is to bring controlled amount of daylight into a space.
Shading systems provide the single most effective strategy for façade designs to achieve visual and thermal occupant comfort along with building energy efficiency.
Below are few different approaches to shading devices. They are grouped here based on their design criteria; but the categorization also reflects on the chronological development and the advancement of the shading system design and evaluation techniques.