Results from a parametric study to assess the daylight amount in rooms with different architectural features

This paper describes the research activity carried out by the Lighting Team of the TEBE Research Group on the daylight availability in interiors. The analysis was done through a parametric study, running a high number of Daysim simulations of a single target room whose architectural features were changed (orientation, window size, room depth and height of an external obstruction). For each case-study, referring to an illuminance of 500 lux and a glazing visible transmittance of 70%, the values of Dynamic Daylight Performance Metrics DDPM and of the energy use for electric lighting (in presence of either a manual on/off switch or a daylight responsive control system) were calculated and the obtained results analyzed to understand how the DDPM and energy demand values change as a function of the architectural features. As a next step, to provide an overall representation of the DDPM results for all simulated case-studies, a graphical tool was developed. The tool was intended to be used by the design team since the earliest design stages to quickly verify the influence of preliminary design solutions on daylight amount. As a further step, which is currently in progress, a set of mathematical models are being developed to predict the daylight availability within a space or the corresponding energy demand for lighting. New sets of simulations were run for this purpose so as to expand the database including more latitudes, illuminance levels and glazing visible transmittances. The final step will deal with the implementation of the models into an interactive software that will allow practitioners getting DDPM and lighting energy demand values by directly inputting the site, spaces architectural features and illuminance threshold. The different steps of the research, the main results which have been obtained during each step and the future developments are described in the paper.