Energy and Circadian Assessment of a Combination Between Integrative Lighting and Daylight Harvesting

Sammanfattning: This study deals with the health and wellbeing of humans who work in offices as well as the energy use for the lighting. The focus is on how integrative lighting and daylight harvesting can be combined in an attempt to reduce the energy consumption while still eliciting a circadian response for the workers. The aim of this study is to investigate a combination of integrative lighting and daylight harvesting. Besides that, the study partly aims to make a literature review on the topic with the intention to find answers for unanswered questions for previous studies. The goal on the other hand is to understand how an integrative lighting system in offices could be engineered to consume less energy that it does today, while still eliciting similar variations of melanopic over photopic (M/P) illuminance ratios. The research methods of this report included primary research of on-site measurements and observations as well as research of literature studies. Moreover, several modelling and simulation software’s within energy and non-visual effects of light were used and analysed in order to answer the research questions. Literature on the subject along with technical information for the chosen light source has been a central and important part of the study, Adaptive Lighting for Alertness (ALFA) was a key factor in order to achieve optimum results. The results correlate with literature and previous research as they both confirm that the circadian entrainment is affected differently by different SPDs. The study shows that a combination of integrative lighting and daylight harvesting reduces the energy consumption, while the M/P ratios were both sufficient and insufficient depending on whether it is wintertime with overcast sky or summertime with clear sky.