LRC Releases Free, Open Access Circadian Stimulus Calculator

The Lighting Research Center (LRC) at Rensselaer Polytechnic Institute has recently released a free, open-access circadian stimulus (CS) calculator to help lighting professionals select light sources and light levels that will increase the potential for circadian-effective light exposure in architectural spaces, utilizing the CS metric. Developed by LRC researchers, the CS metric is a new way to quantify light’s impact on acute melatonin suppression, a marker of circadian system activation.

“Lighting for the circadian system employs lighting design objectives that differ from those typically used in traditional architectural lighting design, and therefore, requires metrics that differ from those currently used by lighting designers,” said Professor Mariana Figueiro, Light and Health Program Director at the LRC.

The results from the Circadian Stimulus Calculator for four different light sources show that the effect of halogen light and even cool white, 6500 K LED light are not significant different, while HPS light has a much lower effect