Nov 3 2010
Acuity Brands (NYSE: AYI), a market leader in innovative energy-efficient lighting and control solutions, took part in a project to relight part of the downtown Tucson, Arizona area using its Bern® Series of Holophane® luminaires, which use energy-efficient induction technology.
The Holophane brand has been a recognized leader in high-quality and lowest total cost of ownership lighting solutions for commercial, industrial, and outdoor applications for more than 110 years.
Home to nearly a million residents, Tucson blends the majesty of the surrounding mountainsides with the excitement of a flourishing city. The city recently developed a master plan to reinvigorate its downtown to bring more local citizens and tourists to the area. The revitalization project focused primarily on Scott Avenue, with neighborhood residents, designers, business owners, engineers, utilities and organizations joining together to create an environment that encourages pedestrian traffic. Enhancements such as a solar-illuminated turquoise trail, a dog water fountain, shade trees and gryphon tracks in the sidewalk are designed to stimulate interest along a street that was once considered a minor artery.
“Scott Avenue flows into Broadway, a main thoroughfare through Tucson,” said Ernie Encinas, Transportation Superintendent for the city of Tucson. “The goal was not only to revitalize Scott Avenue, but to show residents what a downtown stretch of road could look like when the city has the budget to make the upgrades needed.”
During a fast-track design/build project, the city reduced parking along Scott Avenue and narrowed the roadway to make it more pedestrian friendly. Walkways were widened to facilitate access to restaurants, hotels, businesses and attractions, including the Tucson Temple of Music and Art (home to the state’s leading professional theatre), the Tucson Scottish Rite Cathedral, and the Tucson Children’s Museum. The prospect of increased pedestrian traffic, however, raised concerns about safety and security, which led to the installation of a new lighting system.
Scott Avenue was previously illuminated with cobra head, high pressure sodium lamp fixtures that created uninviting yellowish puddles of light and left some areas dark. To replace these, the city selected twin-headed Bern Series fixtures from Holophane to install along both sides of Scott Avenue. The contemporary looking bell-shaped luminaires are part of the Holophane line of GlasWerks® II Euro-Styled fixtures.
“The city plans to install a street car as part of the renovation and earlier worked with a contractor to install some of the track and mount other lighting fixtures in another area,” said Edward Kessler, senior traffic engineer, STANTEC Consulting Services, Inc., Tucson. “The city chose the decorative Bern luminaires because they are aesthetically appealing and their bell-shaped housing mimics the light fixtures that were installed along the tracks.”
To maintain dark, "star friendly" skies, many regions of the country such as the Tucson area are required by law to meet specific dark sky regulations requiring no uplight and restricted light at critical angles. This limits the selection of luminaires greatly and can often create challenges in terms of overall performance and aesthetic appearance. To address this requirement, the Bern Series luminaires provided the city of Tucson a luminaire that not only met all their expectations for quality, color, performance and uniformity of illumination, but also gave them the desired aesthetic appeal to meet their needs for renovating the appearance of the streetscapes. The Bern Series luminaires are classified as IES full cut-off and meet Tucson’s requirements for remaining star sky friendly while the combination of optics and fixture design restrict light at the critical angles, eliminating any direct uplight.
Bern Series luminaires use 85-watt induction lamps, selected for their energy efficiency and white light. Bern Series fixtures offer tool-less entry access to the lamp and electrical components to facilitate maintenance. “Limited parking for service vehicles along Scott Avenue made it especially important to install fixtures and lamps that require as little maintenance as possible,” Encinas said. “The induction lamps provide a soft, white light and have a much longer life than metal halide. The color rendering is excellent so, for example, if someone looks at something red, the person actually sees red instead of another color.”
Fixture spacing varies from 40 to 70 feet, since the luminaires were installed around existing underground utilities. Illumination levels are 1.8 footcandles average over the roadway and sidewalks, with the city of Tucson requiring more stringent light levels than those required by IES for this type of application. “The Bern Series luminaires include a prismatic glass lens that provides a comfortable, even spread of light,” Encinas said. “Pedestrians and drivers see no point sources or sharp shadows—whether they are directly beneath the fixtures or fifty feet away.”
As part of a comprehensive lighting solution, the city is using photocontrols from Acuity Brands’ DTL® controls brand. These save energy and reduce utility replacement costs, offering an integrated intelligent outdoor lighting and controls solution that saves energy by providing both excellent reliability and accurate light sensing. In this application, fixtures are controlled by a photocell and illuminated dusk until dawn. “Comments about the lighting from residents and city officials have been very positive,” Kessler said. “People who live on Scott Avenue are especially complimentary because the lighting has created a safer and more inviting environment.”
Source: http://www.acuitybrands.com/