Matar, Reem2020-11-042020-11-042020-0820181938https://bspace.buid.ac.ae/handle/1234/1684Human centric lighting ( HCL ) is the sum of visual and non-visual effects of light on humans. Not only do we need light to see objects, but recently it was found that light affects much more than that. It was shown that light has an important effect on circadian rhythm of humanbeings, which means that it affects the sleep-wake cycle, in turn it has a significant effect on human’s health, psychological and physical wellbing, and productivity. Given the importance of Human Centric Lighting on us as societies and individuals, many researches were done to evaluate this effect. Educational spaces one of the most important environment that need to provide a good Human Centric Lighting. In order to improve the students sleep/wake cycle, productivity and performance in the school. The aim of the study is to investigate and evaluate different LED luminaire types with different CCTs and light beam distribution in term of circadian light for a typical classroom. The study was conducted through computer simulation to examine how are different luminaires type can influence vertical illuminance (Ev) by adding six vertical calculation surfaces along the classroom. Moreover, evaluating how much different luminaires can deliver Ev to the eye by adding 31 calculation points positioned in every chair at 1.2 m height with an interval of 15 degrees to simulate human head movement towards the whiteboard. In addition, a horizontal calculation plane at the working plane level (0.76 m) to ensure maintaining the recommended horizontal illuminance (EH) which is 500lux. The study evaluated five luminaire types, which were examined with different light beam distributions (narrow, flood, and wide flood) and various CCTs (3000K,3500K,4000K, and 5000k). Additionally, the study calculated the circadian stimulus (CS) for two positions in the classroom to compare between the different luminaires in their ability to deliver good circadian light. The results showed that the lumen value plays an important role in delivering vertical illuminance, and it showed that the luminaire with the highest lumen value delivered the highest CS.enhuman centric lightingcircadian lightcircadian rhythmhuman healthDissertation