New Circadian Lighting Resource (01-15-21)

The Lighting Research Center, Rensselaer, has released materials that can support the development of energy efficient circadian lighting n classrooms and hospitals.  As a press release from the LRC reports the LRC team “published new guidance documents for designing circadian-effective lighting in K-12 classrooms and hospital patient rooms while avoiding increased energy use. . . . For circadian entrainment and improvements in sleep quality and psychological health, high daytime light levels at the eye are necessary, followed by low evening/nighttime light levels in order to achieve a robust 24-hour light-dark pattern. However, the recommended light levels in K-12 classrooms and for general (non-exam) lighting in hospital patient rooms are generally too low for daytime circadian stimulation. . . .  Designers can also increase the circadian-effectiveness of the overhead lighting by increasing overall light levels to 500 lx on the workplane for at least 2 hours during the daytime and using correlated color temperatures (CCTs) of 3500 K or higher. The most energy-efficient technique for designers to consider, however, is the addition of a supplemental layer of narrowband short-wavelength (blue) light in conjunction with typical overhead lighting.” The guidance documents from the LRC are located at      and at

“LRC Issues New Guidance for Implementing Circadian-Effective Lighting in Schools and Hospital Patient Rooms While Minimizing Energy Use.”  2021.  Lighting Research Center, Rensselaer,