Directive 2010/31/EU promotes the refurbishment of existing buildings to change them into nearly zero-energy buildings (nZEBs). Within this framework, it is of crucial importance to guarantee the best trade-off between energy performance and indoor environmental quality (IEQ). The implications of a global refurbishment scenario on thermal and visual comfort are assessed in this paper pertaining to an existing office building. The retrofit actions applied to achieve the nZEB target consist of a combination of envelope and technical building systems refurbishment measures, involving both HVAC and lighting. Energy and comfort calculations were carried out through dynamic simulation using Energy Plus and DIVA, for the thermal and visual performance assessments, respectively. The results point out that energy retrofit actions on the building envelope would lead to significant improvements in the thermal performance, regarding both energy savings (−37% of the annual primary energy for heating) and thermal comfort. However, a daylighting reduction would occur with a consequent higher electricity demand for lighting (36%). The research presents a detailed approach applicable to further analyses aimed at optimizing the energy efficiency measures in order to reduce the imbalance between visual and thermal comfort and to ensure the best performance in both domains.

This paper presents some results of a project that has been aimed at developing an event-driven user-centric middleware for the monitoring and management of energy consumption in already existing public buildings. One of the strengths of the designed system is that it allows an easy integration of heterogeneous technologies and their hardware-independent interoperability. This is a feature of great importance for existing buildings, where already existing controls could be integrated with new technologies to enhance the energy efficiency of a building. The functionality of the system has been tested in a number of representative spaces of already existing public buildings, where the already installed HVAC and lighting services have been equipped with monitoring and actuating systems designed and implemented using commercial off-the-shelf wired and wireless devices. This paper focuses on the energy aspects, which have been obtained by applying the designed system to monitor and control the electric lighting fixtures of different office spaces. The outcomes obtained from the monitored data have shown some significant differences from the expected and previously estimated energy saving results, and this paper offers some possible explanations. Some criticalities, in part related to the characteristics of the commercial off-the-shelf adopted devices and in part to the difficulties encountered in monitoring and analyzing the huge number of recorded data, are outlined.

The use of LEDs in museums is becoming more and more frequent. Benefits are claimed in terms of lighting quality, conservation and maintenance. Nonetheless the impact of LED light on collections preservation is not yet completely explored. The goal of this study was to evaluate, through exposure tests, the colour degradation and fading produced by LED: several white LEDs, with different colour temperature, and a traditional halogen lamp, were used to light up light-responsive samples. The results stressed the importance of the spectral distribution with respect to effective wavelengths in causing colour degradation, and in general white LEDs resulted more suitable, in terms of fading prevention, than traditional halogen light sources