Effects of Correlated Colour Temperature of LED Light on Visual Sensation, Perception, and Cognitive Performance in a Classroom Lighting Environment

Wonyoung Yang,Jin Yong Jeon

doi:10.3390/su12104051

Abstract

Illuminance levels have been standardized and regulated for many purposes. However, the effects of correlated colour temperature of lighting have received little attention in the field. This study investigated the effects of correlated colour temperature of lighting on the brightness sensation, lighting perception, and cognitive performance of 60 students under ambient light emitting diodes (LED) lighting conditions (CCT: 3000 K, 4000 K, and 5700 K; illuminance: 650 lx and 1050 lx) in an actual university classroom. An increase in correlated colour temperature (CCT) led to an increase in brightness sensation. However, increased CCT did not linearly increase lighting comfort. A CCT of 4000 K was considered as the optimum for lighting comfort in educational settings. But in comparison to comfort, higher levels of perceptual properties, satisfaction and acceptance were not affected by CCT from 3000 K to 5700 K. Scores on the working memory test were significantly affected by CCT and illuminance level in men only. The effects of gender appeared in glare sensation and the working memory test. Women were sensitive to glare sensation and had a lower mean score in the working memory test than men. Optimal CCT is more beneficial than increased illuminance in moderately ambient indoor lighting, as it provides better lighting comfort. Further research can look at the long-term effects of CCT on lighting perception depending on brain processing levels and more diverse and in-depth cognitive performance.

Highlights

Lighting is a fundamental component of school classrooms
The effects of a correlated colour temperature of lighting on the brightness sensation, lighting perception, and working memory performance of students were investigated under moderate steady-state luminous conditions
Brightness sensation was found to be affected by correlated colour temperature (CCT)

Summary

Introduction

The parameters affected by lighting in a classroom include the optimal visibility of all information to the students, the mood or behaviour of the students, and the learning ability and performance of students. There have been few empirical studies on the effects of lighting on the academic performance or well-being of school students [1], and not many studies on more specific lighting factors such as correlated colour temperature. A significant amount of research has focused on the effects of lighting in the work environment. It can be assumed that these effects already identified in the work environment may apply to the school setting, and especially to university classrooms. The literature review in this study is based primarily on research conducted in workplace settings

Objectives

Findings

Discussion

Conclusion