Analysis of domestic hot water in residential buildings in Spain

Abstract

Energy analysis in residential buildings considers three main areas of consumption: heating, air conditioning and domestic hot water. Traditionally, the former, heating, has been the most significant area of consumption in Spain but, due to modern technological advances and both the national and European regulations in force, this is no longer the case. The objective of this research is to define some strong, verified consumption patterns which make it possible to compare systems with one another and evaluate their influence on the energy efficiency of new and existing buildings, thereby, making progress toward improving generation systems. Real domestic hot water consumption measurements were collected over a one-year period for more than 500 Spanish properties in five different buildings located in both public and private residential developments. Moreover, a comparative study of the indicators set out in Spanish and other European regulations was carried out, evaluating their impact on energy performance certification. Finally, the suitability of the current indicators, both in quantitative and qualitative terms, was evaluated, concluding that the unit of measurement used in the Spanish regulations is not the most appropriate, and confirming that both seasonal impact and residential development type must be considered due to their influence on domestic hot water consumption.