Researchers evaluating light pipe potential in new Daylighting Lab

Liliana Beltran

Liliana Beltran

An innovative, energy saving lighting system that can pipe healthy, full-spectrum daylight more than 40 feet into a building and potentially raise worker productivity is being tested at the Texas A&M College of Architecture’s Daylighting Laboratory.

Housed in a revolving 20’ x 30’ metal building at Texas A&M’s Riverside Campus, the lab is used to test a solar light pipe prototype developed by Liliana Beltrán, associate professor of architecture. The pipe conducts sunlight from a collector located on the building’s exterior into the lab’s interior through a duct containing highly reflective material. At the terminus, the light is diffused through a film developed by 3M, which is embedded with patterns that spread the light at a wide angle.

Even with partly sunny skies, Beltrán has found that the pipe provides more than three times the amount of light needed to perform ordinary office tasks. The light pipe also produces full-spectrum light, void of the artificial hues associated with fluorescent light. The system, she said, is ideal for lighting a wide variety of multistory building types, including offices, schools, hospitals, nursing homes and retail businesses.

Research has shown that people who work in environments with natural light have higher energy levels than those in artificially lit workplaces and have better sleeping patterns, which makes them happier, more productive and better learners, said Beltrán.

“The pipe delivers very high light levels 30 feet inside a building and can easily carry it 40 feet or a little bit more,” she said. “People using the pipe can receive the same amount and quality of light that deep inside a building as they can from an open window at a building’s perimeter,” she said.

The wheeled lab sits on a concrete track so, with the help of a small tractor, it can be quickly and easily rotated to adjust its orientation and simulate lighting conditions at different locations on Earth.

The pipe design, she said, improves upon existing alternative lighting systems that draw daylight into buildings using fiber optics, or systems that use shorter pipes. Those systems, she said, provide much less light than needed for common office tasks, and the light they cast looks more like electric lighting than natural daylight.

The Daylighting Lab was built with a $75,000 award from the United States Environmental Protection Agency, which picked Beltrán’s light pipe design, then housed in a repurposed railcar container, as one of the top entries in its 2010 [People, Prosperity and Place] ( contest in Washington, D.C., and from private donations.

The new Daylighting Laboratory also supports the research of Julian Wang, an architecture doctoral student testing the performance of a system of remotely operated blinds developed by [Warema] ( , a German company that designs sun shading systems popular in Europe.

In the study, volunteers charged with common office tasks are allowed to adjust the blinds with a mobile phone application to optimize their performance and the optimum light settings are recorded.

“Warema and other daylighting system manufacturers are eager for the results,” said Beltrán.

posted November 26, 2013