The development in the early 1960s of techniques for applying reflective metallic coatings to architectural glass and polymeric films has given a new degree of aesthetic freedom to architects and new sun control capabilities to HVAC engineers. By the use of such coatings and films, the admission of light and heat. through fenestration can be controlled over a wide range, but some unforeseen consequences have also been encountered . Among these is the creation of reflected sunbeams of unprecedented intensity. The purpose of this paper is to show how the direction, intensity, and length on a horizontal surface of such sunbeams can be predicted and, in some cases, controlled.

Units: Dual