Adjustable lighting system based on circadian rhythm for human comfort

Abstract

The artificial lighting condition in which humans are exposed have been proven as a harmful factor on their well-being, which is regulated mainly by circadian rhythm. Especially since the COVID-19 pandemic, where external factors forced the society to adapt into new standards when it comes to their jobs and regular activities, lockdowns and work-from-home made most people start spending a portion of their life exposed to artificial sources of light. Technological advances have made lights more efficient and improved their intensity. Light-emitting diodes (LEDs), for example, generally produce high-intensity bluish tone light, which may affect the circadian rhythm. However, it is possible to create lighting systems able to vary the intensity and correlated color temperature (CCT) of the lighting. This work proposes a lighting system that allows adjusting the intensity and CCT of light via remote control on a smartphone application synchronized with time, following a pattern that aims avoid the undesirable artificial lighting effects on circadian rhythm. Using two LED arrays containing 10 LEDs each, suitable results were reached, presenting maximum difference of 3.35 % for CCT and 5.57 % for luminous flux in comparison with reference values.