Instant-on benefit of LED low-bay lighting maximizes energy savings for school

Dec. 12, 2013
New SSL in a gymnasium application allows teachers and coaches to turn power off when no one is using the facility whereas HID lights had previously burned throughout the day.

Acuity Brands has announced an LED lighting installation at Dobson Elementary school in the Surry County School District in North Carolina. The low-bay solid-state lighting (SSL) products provide baseline energy savings relative to the prior metal halide (MH) fixtures. Moreover, the fact that the MH lighting required a delay of 5 to 15 minutes before reaching full brightness makes the instant-on LED fixtures virtually even more efficient because the school had left the MH lighting on all day but can switch the new lighting on and off based on usage.

The Dobson school project was a trial for the school district that had been looking at options for saving money by reducing energy consumption. The gymnasium was an easily identified energy sink because the schools even left the lighting on into the evening for maintenance workers. The 400W MH fixtures in the district's gyms were both difficult to power down due to the use of multiple breakers along with the warm-up issue.

"We chose Dobson Elementary for the pilot program as it is one of the older elementary gymnasiums," said Robert Draughn, director of plant operations for the Surry County School District. "We were ultimately interested in the results that could be achieved at an affordable cost, while improving energy savings and foot-candle levels."

The district worked with State Electric Supply to contemplate a retrofit for the ten 400W fixtures in the gym. Fluorescent lighting was the primary initial option, but the most-efficient fluorescent products still carried high upfront costs and such a system would still incur significant maintenance and relamping costs.

State Electric suggested LED lighting as an alternative that would provide energy and maintenance savings, deliver instant on and off capability, and be low enough in terms of power consumption to operate from a single switch. Ultimately the district installed ten IBH low-bay LED fixtures from Acuity's Lithonia Lighting brand in the gym over a three-day period after State Electric documented the potential savings.

"We realized the fixture cost was minimal compared to the savings we could achieve with LED luminaires," said Draughn. The school projects that it will save $1350 per year. "The significant savings will essentially pay for the new fixtures in only two years," said Dale Mayes, branch manager at State Electric Supply and the lead specifier on the project.

The school, meanwhile, got a surprise in terms of light quality as well. "The performance of the lighting was extremely impressive," said Draughn. "In most places the foot-candle levels improved more than 50%." The school also said that the lighting eliminated dark spots and shadows.

The trial project will lead to LED-based lighting installations on additional school campuses. There are already projects planned at two high schools, one middle school, and six elementary schools.