Design and Energetic Analysis of an Advanced Control Upgrading Existing Lighting Systems

This paper considers the possible actions to reduce the energy consumption of lighting systems as more efficient luminaires and advanced controls. The upgrading of existing lighting systems requires special care and appropriate criteria in consideration of the various technical/economic aspects. A case history of three classrooms made at the Engineering Faculty, University of Rome “La Sapienza,” is described to validate the criteria that are proposed. An advanced control system organized by adopting the Konnex standard turns on/off and regulates the lights according to the actual presence of activities and the actual availability of daylighting. In order to associate the energy savings with the costs of installation, a classroom was arranged with a “cheap” solution consisting of “on-off switching” control, maintaining the existent luminaires, and another one with an “expensive” solution with the replacement of the luminaires and a “dimming” control. The architecture includes a supervisory and metering system for the two classrooms and a third one without controls, which is assumed as a reference for comparison. The results of a year of monitoring campaign are compared with the preliminary evaluation done by means of the standard EN15193 methodology.