Improvement of Energetic Efficiency of Buildings: Contributions of Passive and Active Solutions

Clito Afonso, and Ricardo Pereira

Universidade do Porto, Faculdade de Engenharia, Depart. Engª Mecânica - Porto, Portugal

Abstract: The building sector has a significant weight in energy consumption and a high potential for increasing its energy efficiency. With the enforcement of the energetic certification, it has been tried to find and select different solutions that presents less energy consumption and waste, which translates into an effective reduction of CO2 emissions. It is in this perspective that this work fits, since its aim is to evaluate the contribution of passive and active solutions of a hotel located in Portugal, for the improvement of the energetic efficiency, as well as to evaluate the contribution of some renewable energy sources. Besides, the cogeneration remains as the most effective technology on the conversion of primary energy into electricity and heat. The application of cogeneration technologies in the buildings sector gains notability facing the rise of fuel prices. To improve the building performance, there were made several changes on the dynamic model used with the goal of evaluating the contribution of different solutions. It was concluded that they contribute to a reduction of thermal needs of 25.2% and avoided emissions of equivalent tons of CO2 of 30.4%. The analysis of the technical/economic viability of the implementation of the CHCP becomes feasible with an absorption chiller to produce cooling. The payback period is less than 8 years which proves that it is an economic viability of this technology.

Key words: CHCP, energy analysis, avoided CO2 emissions, economic analysis