Eliminate high pressure sodium lighting, create more perceived light output and lower energy demands.
LEDs deliver better uniformity with 53% savings.
The Prairie School in Racine, WI is a 1965 Frank Lloyd Wright-inspired K-12 facility located in a wooded, rural setting. The old sodium lighting for the parking lots had a yellow cast that impaired color rendering and caused patchy illumination. At 250W, they consumed 300 system watts per fixture. In addition to saving energy and improving light quality, new luminaires would need to complement the site’s historic design.
Using the existing poles, area fixtures were upgraded to LED light bars that deliver 8,040 average lumens yet consume only 141 system watts each. This provides a savings of 53% or 159 system watts over the original installation. Taking into account the 50,000-plus hours of fixture life, the facility team can look forward to over 16 years of maintenance-free operation.
A 1.01 average mean footcandle level was achieved with an improved maximum/minimum ratio of 8:1. Even though footcandle levels are reduced from the high pressure sodium installation, the new LED system provides a dramatic increase in perceived light levels and safety for pedestrian and vehicular traffic.
“This project is from 2008 and at the time, we really had to provide energy and maintenance projections to prove that LEDs were the right solution. The contrast between the sodium and LED lights is striking,” says John Casadonte, Vertical Marketing Manager for Cree. “Because LED efficiency continues to advance, if we did this project again with the latest fixtures, we could deliver an additional 50% energy savings.”
INFORMATION AND IMAGES COURTESY OF CREE