Research Highlights
Superior Lighting for Sacramento's Senior Citizens
Tunable white LED systems find health benefits, energy savings of 68 percent
Nearly 1.5 million people in the United States reside in nursing homes. Primarily care centers for the elderly, nursing homes are modified living spaces that make daily tasks—such as bathing—easier on occupants and their families. One such facility, the ACC Care Center in Sacramento, Calif., has taken modifications for increased comfort to new levels with tunable white lighting.
Tunable white light-emitting diode (LED) systems enable adjustments in spectral power distribution and light output—that is—they enable light to appear either cool or warm and bright or dim with a simple wall-mounted control interface. Prior to the lighting upgrade, the ACC Care Center used fluorescent lighting in its halls, resident rooms, and bathrooms. The incumbent systems—evaluated in August 2015 by researchers at PNNL—did not meet illuminance level recommendations set by the Illuminating Engineering Society (IES). This meant that visually demanding tasks, such as reading or personal grooming, were difficult to perform.
GATEWAY demonstrations, supported by DOE’s Solid State Lighting (SSL) program, facilitate a hands-on experience for evaluating SSL products. High-performance LED products are tested in real-world situations that cannot be replicated in a lab, providing valuable information on product performance and cost effectiveness, disseminated through presentations and reports.
The Sacramento Municipal Utility District selected the ACC Care Center for a trial installation of tunable white LEDs. After the trial install in several rooms, one corridor, and the nursing station was complete, the PNNL research team again evaluated the lighting—as part of DOE’s GATEWAY Program—and found that the illuminance levels in all upgraded areas now exceeded IES recommendations for the over-65 age group. For example, IES recommends that restroom vanities have a minimum vertical illuminance of 400 lux at a person’s face as he or she is facing the mirror. The incumbent system provided only 200 lux, while the upgraded LED system can provide as much as 3,900 lux and can be dimmed to lower levels to meet the varying visual needs of the residents. The PNNL researchers also found an estimated energy savings of 68 percent from the upgraded corridor lighting—referred to as Cherry Lane.
Heightened Health
The impact of the trial system wasn’t just in the bank—the health of residents was impacted, too. The spectral tuning and dimming ability of the LED systems likely suppressed the morning production of melatonin in ACC Care Center’s occupants by providing bright, cool light in the morning, and likewise, it did not suppress melatonin production in the evening and nighttime hours by providing warm, dim light during those times. Recent evidence suggests that this strategy enables occupants to sleep better. Among three residents studied post-installation, all began consistently sleeping through the night, and one significantly reduced their use of psychotropic and sleep medications. The same three residents had a 41 percent decrease in agitated behaviors such as yelling and crying. While many factors affect these health-related outcomes, the lighting changes likely contributed to them.
ACC Care Center staff uncovered other benefits, as well. Recorded patient falls decreased in the Cherry Lane corridor. Residents of other corridors began “hanging out” in the updated corridor, and frequently requested that their caretakers take them to Cherry Lane.
Many family members of residents outside of the Cherry Lane corridor have asked when their loved ones will receive the new lighting. The center plans to update the remaining corridors in early 2017 and will include the lessons learned from this pilot project in their future expansion and remodel plans. Meanwhile, the attending physician is sharing information gathered from the installation with the medical community.
For more information, read the GATEWAY report.
PNNL Research Team: Robert Davis and Andrea Wilkerson