By Leanna Ehrlich, OSI Intern
Emory University’s commitment to sustainability over the last decade includes updating one of the largest uses of energy on campus: lighting fixtures. OSI recently spoke to Kevin Keefe, an Electrical Engineer at the University, and he detailed the steps that Campus Services has taken to reduce lighting’s energy use, from using more efficient Light Emitting Diode (LED) bulbs, to timing light use with room occupancy, to the challenges and successes of retrofitting spaces on Emory’s historic campus.
“I started here at Emory 6 years ago,” Kevin said, back when only 5% of all lights on campus were energy-efficient LED lights, mostly confined to surgical suites and labs. Back then, Campus Services began lighting improvements by first targeting the easiest changes that would yield the biggest results: the parking decks, massive spaces that are lit 24 hours a day. They were “the lowest hanging fruit,” Kevin said: the easiest bulbs to replace and those that would make the biggest difference in energy savings. The first deck to be updated, Lowergate, saw energy savings of up to 60% through replacing bulbs with lower-wattage LEDs; future deck updates saw savings of up to 80%, especially in spaces with more daylight, allowing the lights to be selectively dimmed or turned off entirely during brighter times of day. While there could be additional energy savings from turning off parking deck lights at night and activating motion-control sensors, Campus Services’ priority is student and staff safety, so for the foreseeable future, parking decks will always be lit at night.
After prioritizing parking decks, Campus Services turned toward new construction and retrofitting spaces. All new buildings now use LED lighting from inception; the first such building was Eleonore Raoul Hall, which opened as a student residence hall in 2014. LED lights have now been used in new projects like the Emory Student Center and restored buildings like Convocation Hall. LED lights can be dimmed, used in occupancy-controlled lighting, and integrated with the heating and cooling systems, allowing the University to fine-tune energy savings by carefully calibrating room occupancy (through carbon dioxide and movement sensors, as well as pre-uploaded schedules) and ensuring that lighting, air, and temperature controls are perfectly suited to a room’s occupancy at all times. While the process of converting lighting in all buildings to LED bulbs is still ongoing, Campus Services is pursuing additional energy savings by transitioning fluorescent bulbs to lower wattage until they can be replaced entirely by LEDs.
In addition to public spaces, laboratories are a major target of lighting controls, given that “they are the biggest energy users on this campus,” Kevin said, “bar none.” There, too, occupancy sensors are being deployed to more efficiently heat, cool, and light the spaces. Occupancy sensors, Kevin explained, have made the biggest difference in campus-wide energy savings. “You’ll get more savings through aggressive lighting control than just swapping out [older bulbs] for LEDs,” he said.
While all new spaces are built with the intention of LED lighting, challenges have arisen in retrofitting older spaces, particularly around preserving Emory’s architectural integrity and original design vision. At the Goizueta Business School, Campus Services faced challenges in installing LEDs that would function with the tiered classroom seating structure, where professors were used to having control of the professionally designed lighting that would allow them to illuminate different parts of the classroom depending on their lectures’ needs. Even though there were some speed bumps along the way as Campus Services learned how to program the LED system to have the expected classroom capabilities, responses to the upgrades have been very positive.
At Goizueta and beyond, the customizable programming of LED lights has opened up new horizons for lighting. The warmth of lighting in each space can be individually adjusted, without needing to consider bulk warehouse purchasing for the whole university, as in years past. Now, the lighting setting in each building can be carefully calibrated to match the intent of that building’s design. The settings can even be changed to have cooler lighting temperatures during the day and warmer temperatures at night. Previously wasteful uses of architectural lighting, like cove lighting, can still be included in retrofits of space because LED is so efficient: even if the cove lighting doesn’t provide any ambient light, only bouncing off the recess in which it is set, the low dimming of LED mean the space can be lit with 1 watt per foot, providing a beautiful illuminating glow without energy inefficiency. This feature can now be seen in the retrofitted stairwell ceiling of Convocation Hall. All across campus, there is more than meets the eye with the lighting structures. From parking decks to new construction to the most historic buildings on campus, Emory is pursuing energy efficiency alongside functional and beautiful lighting—done so well that few people will likely notice a difference.
Do you have suggestions or comments about on-campus lighting improvements? Email emorysustainability@gmail.com!