Autor/autori: Anca DUTA, Ion VISA, Macedon MOLDOVAN, Mihai COMSIT

Abstract: The efficient use of energy is a compulsory step towards sustainable development. Regardless the source (fossil fuel or renewable), energy consumption should be efficient to protect the resources and to lower the overall costs. This is particularly valid for buildings as worldwide over 90% of the built environment is non-efficient. This makes the already built environment one of the major concerns and raises problems that are now-a-days approached by researchers and practitioners. Old buildings need to be refurbished, to increase their energy efficiency and to reduce the exploitation costs but major barriers were identified, related to architectural and construction constraints and to the investment costs. To prevent these problems in the future, the new buildings need to be designed from the beginning as energy efficient. The paper presents a comparative analysis of several novel solutions aiming at energy efficiency in old and in new buildings. Various insulation systems are discussed (for the opaque and glazed surfaces), along with energy saving measures: for thermal energy (temperate concrete, thermal zoning of the radiant surfaces, natural ventilation, night-cooling, etc.) and for the power consumption (maximal use of natural lighting, light tubes). The implementation of new concepts of Building Energy Management Systems is also discussed, as a compulsory step in implementing renewable energy systems in energy efficient buildings

Keywords: Energy Efficiency, Sustainable Built Environment, Building Energy Management Systems