Environmental sustainability of a low-temperature heating system : A case study

Abstract: Nowadays, 40% of annual global CO2-emission is caused by the building sector. 27% of these emissions are coming from building operations and the main use of energy in buildings is heating. With the growing problem of global warming and the European goal of carbon neutrality by 2050 one of the most effective ways to reduce emissions from buildings is to explore environmentally sustainable heating alternatives. Therefore, this study's objective is to perform a life cycle assessment (LCA) of a low temperature heating system located on Aran Islands, Ireland, in order to evaluate its environmental impact and environmental sustainability in comparison to an old conventional heating system. The LCA consists of the entire lifespan of the LTH system including drilling of boreholes, production and installation of heat pump, heat exchanger and floor heating systems, systems annual operation for a 20 years period. End-of-life scenario is excluded from the LCA. SimaPro software is used to make a model of the life cycle using Ecoinvent database for inventory data while ReCiPe Midpoint (H) and endpoint (H/A) impact assessment method is used to assess the environmental impacts of the system. The results of the LCA show that operation and maintenance of the LTH system stand for approximately 80% of emissions across all 18 midpoint impact categories. When compared to an old conventional heating system, consisting of a diesel boiler and burned coal at a fireplace, the LTH system shows considerable improvement in terms of environmental emissions across all impact categories and thus can be considered as a more environmentally sustainable alternative for house heating.