Environmental impact assessment of building energy systems

This chapter deals with energy/exergy and environmental analyses of a low exergy heating system. A building with a volume of about 392 m3and a floor area of 140 m2is presented as a case study. For this building, four different heating options are investigated, namely, (1) electric boiler, (2) ground heat pump system, (3) standard boiler, and (4) solar collector. In this regard, an energy and exergy analysis is employed to assess their performances and compare them through energy and exergy efficiencies. Also, CO2, NOx, SO2emissions of the considered systems are determined and compared with each other. Overall exergy efficiencies of the heating systems are found to be 4.0, 10.1, 7.6, and 35.7 %. CO2, NOx, SO2emissions rate per year (kg emission/year) calculated for considered cases as 10,726.32, 4,224.17, 3,737.56, and 337.67, 11.14, 4.39, 3.40, and 3.35, and 116.34, 45.82, 3.68, and 3.66, respectively. The lowest environmental impact is provided by case 4.