Why Tubular Daylighting Devices Might Be Wrong For Your Business
By Torrin Greathouse | June 21, 2016
There are more natural lighting options on the market now than ever, with a range of specialized designs available. Tubular daylighting devices are a unique skylight design which has been adopted by many businesses. They offer a unique set of benefits, however, they might be the wrong choice for your facility. Here is a breakdown of the benefits tubular skylights offer, as well as why they may or may not be a good fit for your building.
Benefits of Tubular Devices
Tubular daylighting devices employ highly reflective light tubes to channel light from the roof down into the building. This not only allows them to provide a higher intensity of light than traditional skylights, but also to provide light for longer hours. Tubular skylights use a compact design with a rooftop dome between 10”-20” in diameter, which reduces the heat gain and loss that skylights typically create by 20-30%. The most significant benefit of these skylights though, is that the light tubes can be curved and angled to circumvent ceiling level obstructions, such as electrical lighting or HVAC ducts, allowing them to bring natural light into spaces where other skylights could not.
While all of these features are impressive on paper, there are several issues tubular daylighting devices face which may decrease their efficiency in your facility. While there are advantages to their compact design, it is also one of their downfalls. Because the space the light enters through is so small, more tubular skylights are needed to bring in the same amount of light as other industrial-sized skylights, which results in using up a large portion of roof space—nearly 5-7%—to ensure proper levels of light. Since so many tubular units are needed to light a building interior, they are better suited for illuminating small spaces such as hallways, restrooms, and private offices.
Another key problem tubular daylighting devices face is diminishing light intensity. If the light enters the dome at a low angle, it will be reflected multiple times before entering the interior space. Even with the most reflective materials, this results in a 3% loss of intensity for every ten feet that the light travels. This loss of intensity can be even higher if the tubes need to curve sharply around any obstructions.
Tubular daylighting devices are ideal for bringing healthy, diffused natural light into offices or other small spaces, while generating minimal heat loss or gain. They also function well in areas with drop ceilings or ceiling level obstructions that prevent larger skylights from being integrated. However, if you need to illuminate a larger commercial space with fewer skylight units, your facility will be better suited for other natural lighting solutions such as solar tracking skylights.