- Project: Improved lighting quality and energy efficiency in the library
- Jurisdiction: Wayne Township, N.J.
- Agency: Wayne Township Public Library
- Contractor: LAN Associates
- LED Luminaire Manufacturer: Kenall Lighting
- Cost Savings: $5,530 plus a one-time rebate of $2,100
Since its founding in 1922, the Wayne Township Public Library in Wayne, N.J., has undergone many changes to accommodate residents and expanding collections, including significant remodeling and a grand opening in 2000. At that time, metal halide (MH) floodlights were installed around the library’s interior perimeter, providing harsh, glaring light that did not illuminate the area efficiently and burned out quickly. Recently, the library board approved funding for updated lighting.
Wayne Township retained New Jersey-based architectural and engineering firm LAN Associates to meet the challenge of providing uniform light while reducing energy and maintenance expenses.
“The township’s maintenance crews have been replacing the burned out floodlights every six months at a cost of $95 per bulb and with a reduced staff because of budget cuts it has become extremely difficult to keep up with the constant replacement,” says Mayor Christopher P. Vergano.
LAN Associates Director of Electrical Engineering, William Hodges, proposed eliminating the 14,400 watt perimeter MH floodlights and installing 14,216 watt and four, 160 watt LED high bay luminaires. Hodges also recommended daylight sensors to make use of the library’s large windows.
The LED luminaires are suspended from the ceiling and mounted an equal distance apart to maintain a uniform level of illumination. They have a dimming and control system connected to a photocell to permit daylight harvesting. Lighting levels in the space are maintained at a specific set value, and the artificial light from the LED luminaires ramp up and down depending on the available natural ambient daylighting. The lighting controls have a built-in safety factor to make fine adjustments to the artificial lighting levels unnoticeable to the room occupants.
The new LED luminaires have an “up” lighting component, which eliminates the “cave” effect of dark ceilings and articulates the size and scale of the room. These lights are anticipated to last approximately 60,000 hours (over 14 years of operation) before needing any maintenance or replacement.
Before the lighting upgrade, the library’s lights were on seven days each week, costing the township approximately $5,400 annually. The installation of the LED luminaires reduces the energy consumption by nearly half, and, even without taking the daylight harvesting into account, the library has an energy savings of approximately 56 percent.
Moreover, the high cost of maintaining the floodlights is virtually eliminated, as the old MH bulbs and ballasts no longer need to be replaced on a continuing basis.
The township also is saving additional taxpayer money through rebates of $150 per luminaire offered by the New Jersey Board of Public Utilities.