Optimization of the Window Design in Offices for a Proper Circadian Stimulus: Case Study in Madrid

Abstract—The circadian rhythms, endogenous cycles that repeat almost every 24 hours, must be synchronized by daylight stimuli, particularly due to its short wavelength fraction. In this way, insufficient exposure to daylight or its spectral equivalent in electric lighting can endanger human health. The main aim of this research is to develop a methodology in which circadian stimulus (CS) values can assist to the choice of an office window design, in order to promote a good circadian rhythm and to benefit human health and well-being. A room model located in Madrid is presented as a study case, having different variables such as the window measures or the environment reflectance values. It is concluded from the results of this study case that CS and SPD are highly conditioned by the indoor environment reflectance and therefore, also affects to the minimum window size.