The New prEN 15193-1 to Calculate the Energy Requirements for Lighting in Buildings: Comparison to the Previous Standard and Sensitivity Analysis on the New Influencing Factors

The differences included in the new version of the standard prEN15193-1 to calculate the LENI were analyzed, especially focusing on the approach to calculate the daylight supply factor (FD,S). The estimation of the daylight availability does not only rely on the calculation of the daylight factor but it also accounts for the climate, the orientation of openings, and the presence of mobile sun shades for glare and thermal control. A sensitivity analysis on these factors was carried out, complemented by a set of case-studies (simple reference rooms with different site and architectural features) for which the LENI was calculated.