For Electric Customers
Light tubes or pipes are usually installed in the roof of a home or the outside wall of a building to allow sunlight to reflect through the opening. A reflective material inside the tube directs the sunlight down the tube and with the help of a diffuser, distributes it throughout your home or building. Some light tubes have directional collectors, also called reflectors, which assist in collecting additional directional light down the tube.
Short and straight light tubes tend to be more efficient in transmitting light. Longer light tubes, angled light tubes or ones that are flexible can cause part of the light intensity to be lost. To minimize light loss, it is crucial that the tube line has a high reflectivity. Some manufacturers indicate their materials reflect up to 99.5% of the light. To further optimize the use of solar light, a tracking device, called a heliostat, can be installed to track the sun and reflect the solar light into the light tube throughout the day.
Existing lighting systems in your home or building can be modified with light sensors to turn lighting off when an adequate amount of light is supplied through the light tube and back on when the amount of light diminishes.
For more information, visit the U.S. Department of Energy website
or learn more about daylighting on the ENERGY STAR® website