What Options Are Available for Industrial & Commercial Skylights?
By Jeff Brain | March 02, 2015
The benefits of sustainable lighting are becoming more obvious as electricity costs rise and environmental awareness spreads. Unlike electric light fixtures, which account for 56% of the average company's electrical costs, skylights fill indoor spaces with cost-free, renewable sunlight.
Commercial skylights are more sustainable and cost-effective than any other commercial lighting option. Even highly efficient LED bulbs still require electricity. Learn how the following skylight options conserve energy.
The following three skylights are considered "passive," because they do not have moving parts, and they rely solely on the sun's position to bring natural illumination through their panes.
1. Fixed and Ventilating Skylights
Fixed and ventilating skylights are the most basic passive commercial skylight option.
How they work
Both fixed and ventilating skylights follow the traditional window-in-the-roof design. The primary difference between the two being that while ventilating skylights can be opened to let in air, fixed skylights are sealed. Both have a stationary design, so the amount of light they receive depends on their position on the roof and the time of day.
They require very few materials and man hours for the installation, so the initial cost is minimal. Ventilating options can also aerate spaces with heat-generating machinery.
Fixed and ventilating skylights only work when the sun shines directly through them. Ventilation is limited by outdoor temperatures and wind conditions. Debris and condensation can also accumulate on flat surfaces.
2. Prismatic Skylights
Prismatic skylight options have an acrylic, polycarbonate, or polystyrene lens with ridged or rounded prism designs infused into the material. The prismatic design is meant to insulate the interior from direct heat and diffuse the sunlight in different angles and directions in the room.
How they work
The outer layer of a prismatic lens is infused with a ridged or rounded prism designs that allows it to push light down while diffusing the brightness of the sun as it moves across the sky.
Unlike fixed or ventilating skylights, prismatic skylights reflect sunlight in multiple directions throughout the day. They also reduce glare which can harm the eyes and distract workers from performing tasks well. They do not provide outdoor views, as so they are perfect for industrial spaces with minimal aesthetic concerns.
Each prismatic layer blocks some of the light that can enter the space below. Prismatic skylights are also, like fixed and ventilating skylights, dependent on the sun's relative location.
3. Tubular Skylights
Tubular skylights have highly-reflective cylindrical lightwells, capped above the roof and at the ceiling by transparent lenses.
How they work
The reflective interior of the lightwell reflects the incoming light downward and can bend light around ducts and other obstacles, potientially extending bright, natural light through attics or multiple stories.
The U.S. Green Building Council (USGBC) found that tubular skylights distribute light more evenly and efficiently than other passive options. Small openings and diffusing lenses help prevent heat gain and are ideal for small enclosed spaces.
Condensation buildup is a concern when insulation does not prevent hot, cold, or humid air from seeping into the lightwell. In addition, these skylights are not optimally sized for commercial applications.
Active skylights have moving parts which help maximize light flow and prevent temperature fluctuation in your facility.
1. Fiber Optic Systems
While they do not fit the traditional definition of a skylight, fiber optic cables can be used to transfer sunlight into indoor spaces.
How they work
Outdoor solar panels with multiple lenses collect sunlight, and then send it across a series of fiber optic solar cables to indoor light fixtures that spread the light through the room.
Fiber optic options are ideal for rooms that share no walls or ceilings with outdoor spaces. They recreate the intensity and health benefits of natural sunlight without the need for direct access to the sun’s rays.
Running cables through walls and ceilings is expensive and time-consuming. Fiber optic systems also require the use of solar panels, which depend on the amount and location of available sunlight.
2. Solar-Tracking Skylights
The Ciralight SunTracker is one example of a solar-tracking skylight that uses solar power and GPS technology to follow the sun through the sky, providing healthy, natural sunlight throughout the day.
A solar-powered GPS unit locates the current position of the sun, then a motor moves a set of mirrors so that the mirrors are in perfect alignment with the sun and can reflect the sun’s rays down into a lightwell towards the interior of a building. Finally, a diffuser lens distributes the light evenly throughout a space.
While passive skylights create glare and light pooling, solar-tracking skylights reflect and diffuse direct sunlight, optimizing both comfort and brightness. Thanks to the GPS tracking system, sunlight is consistently available for 10+ hours per day.
Solar-tracking skylights do cost more than passive alternatives upfront, but they will provide the shortest payback period of all options.