Energy and Exergy Analysis of Heating and Cooling Systems in the Italian Context

Energy saving and emissions reduction are both affected by the energy efficiency of the built environment and the matching between the quality of the energy carrier and the quality of the required energy. Taking into account qualitative aspects of energy leads to the introduction of the exergy concept. Heating and cooling of buildings require low valued energy, but space climatisation is often provided through high exergy sources. This study is related to the IEA ECBCS Annex 49 “Low Exergy Systems for High Performance Buildings and Communities”. The aim of this paper is to compare different existing technologies for heating and cooling, from both the energy and the exergy perspective. The issue of the exergy of renewable energy sources, such as solar energy and natural heat sinks, is addressed. The sensititivity of the analysis to climatic conditions is studied, by applying it to the main Italian climatic zones. Potential and limits of the energy and the exergy approach are compared and discussed.