Overview

We provided a lighting upgrade in the campus gymnasium that has improved lighting quality and controllability, while benefitting the University’s budget through resulting energy savings. Nittany Lion fans and athletes are both getting a much better view to watch or participate in their favorite collegiate athletics at the PSU Scranton Campus.

The gymnasium was previously illuminated with twenty-four 400 watt, high-pressure sodium (HPS) high bay luminaires. Due to long restart times and lack of automatic controls, the luminaires were consistently left on throughout the day, remaining energized for approximately 15 hours per day. Typical lifespan of HPS lamps are ~24,000 hours, which requires the existing lamps to be replaced approximately every five years.

In addition to requiring excessive energy, the HPS lamps have additional limitations; (1) they are fragile, and the glass lamps were frequently destroyed from impacts; and (2) HPS lamps have poor color rendering properties, which further detracts from the lighting quality, and the average 40 foot-candle illumination in the gymnasium fell short of the University standard of 50 foot-candles.

Solution Details

After providing options and analysis, PSU chose to replace the existing HPS luminaires with twenty-four 238 watt, dimmable LED luminaires. The new lamps have a life expectancy of 200,000 hours, which is further extended by the fact that the lamps can be de-energized when the area is not in use via manual wall switches, occupancy sensors, or scheduled on/off times.

At full brightness, the illumination in the gymnasium now exceeds the University standard at 60 foot-candles, with the capability to dim to approximately five foot-candles when a low lighting setting is needed. Customizable control is further enhanced through occupancy sensors, which were added and programmed to control the luminaires in banks of four, to create six zones. Additional control zones were created to accommodate functions that might require alternate lighting options.

To minimize costs of re-wiring, wireless addressable modules were added to each luminaire. The emergency lighting, which was previously achieved via 500 watt halogen flood lights, is now incorporated into the new LED luminaires, eliminating the need for the existing emergency halogen luminaires. Additionally, the LED luminaires contain no glass or hazardous materials like sodium and mercury, which were present in the HPS lamps.

As a result of the lighting improvement project, the total lighting load was reduced by 48% at full brightness and by an even greater percentage when dimmed for general use. Due to the instant on/off and dimming characteristics of LEDs, the fixtures are seeing a 50% reduction in ‘on’ time and are typically dimmed to 50% illumination for normal conditions, resulting in even more energy savings. The new lighting design delivers an 80% kWh savings, while providing better color rendering, reduced maintenance cost, and a more flexible and pleasing lighting environment.