Entech Collimating Skylights - Patented Technology
What Is Collimation?
Collimation is the technique of redirecting sunlight, which arrives from all directions from the sky above, to the desired interior space of the building below, throughout the day and throughout the year. The easiest way to describe collimation is through the graphic shown to the right. For illustration, sunlight is depicted as entering at 75° off vertical (Red) and 45° off vertical (Blue).
The angles of the sides of the collimator are designed so that the angles of the off vertical sun rays are reduced with each reflection. Consequently, the angles of the light rays leaving the bottom of the collimator are less than 30° off vertical on their way to the working space or merchandise area below. The collimator can be designed so that no light rays leaving the collimator are greater than a 45° angle for all angles of the sunlight entering.
The result is that glare from the Entech Collimating Skylight can be eliminated while the light throughout the day and the year is directed to the desired space below the skylight.
How Have Others Tried To Solve This Problem?
Other lighting designers have used a variety of ways to eliminate the glare, or minimize light coming into the lit space above a 45° angle. One method is the light well as shown in the graphic to the right. These techniques are described in a presentation entitled, “Advances in Lighting Design with Skylights” by Jon McHugh at the Heschong Mahone Group, and Lance Livingston at Lighting Technologies, Inc.
The Advantage of Collimation
Entech Solar has a great advantage over the light well approach since our ECS blocks the high angle glare light beyond 45° from the skylight dome like a deep light well, but without the light well optical losses.
In reviewing conventional electrical light fixtures, our collimator does for our skylight what a parabolic reflector does for a high-output metal halide electric light – directing the light into the working space within 45° of the vertical optical axis of the fixture and blocking the high angle glare light beyond 45°.
