An Evaluation of LED Ceiling Lighting Design with Bi-CCT Layouts

Abstract

Light-emitting diodes (LEDs) became an important home-lighting device. Due to the property of high efficiency LED lighting sources, thus we expected to apply high efficiency LED lighting to improve or enhance our lighting environment. The purpose of this study is to design LED ceiling lightings layout based on evaluating human’s physiological responses and subjective feelings, where the experiments were conducted in the office-like laboratory. We had four experimental combinations included two Correlated Color Temperature (CCT) and two different types of lighting sources (lower Blue-value and high-efficiency). Two different types of lighting sources, one was that the lower Blue-value lighting sources was equipped at the center of the device, the other was that high-efficiency equipped around the lower Blue-value lighting source. Six participants were recruited in this study to perform sheet, laptop-typing, and tablet-searching tasks under the four experimental combinations. In addition to working performance measures, heart rate, Galvanic Skin Response (GSR), eyes blink duration, blink time, and critical fusion frequency (CFF) values were measured as well. The results showed that CCT 4,000 K-high efficiency lightings design would affect human’s physiological alert and stress. Thus we suggested the CCT 4,000 K-high efficiency participants had lower Tablet-searching error rate higher physiological alert and less eye fatigue.