Control systems for indoor lighting and computer simulation: analysis and comparison between software packages capabilities and results on a real case study

In the last years, computer capabilities have evolved rapidly and also the way to simulate building physics phenomena is changed and more developed. Each simulation software is developed with a less or more similar aim, using different algorithms and models and being used by people with different profile: specialist, architects, engineers, installers, etc. This paper deals with the analysis of capability of some of the most utilised software used to predict indoor lighting, including natural daylight contribution and assessment of energy consumption and savings related to specific design options. Furthermore, two of the analysed software have been tested simulating a case studying. Results show that data calculated by different programs can be very dissimilar. Moreover, consumption calculated using the same software (i.e. Dialux), but using methods proposed by two different technical standards can be very different. It obviously means that while approaching an energy study of a lighting set up, it is necessary to do an accurate selection of the tools to be used, and it is necessary, as well in this case, to analyse critically the results.