Engineering eco-design of heat exchangers in domestic heating systems using life cycle assessment methodology

According to the European energy consumption reports, the highest energy/fuel consumption in the residential sector is due to space heating, followed by water heating. Generally, the product used to warm water in residential buildings is a boiler system where a heat exchanger is the core of the system. The paper provides a Life Cycle Assessment analysis of a traditional heat exchanger used in domestic boilers with the aim to identify critical aspects and environmental hotspots for the development of a novel concept of the heat exchanger. The methodology used to collect eco-design guidelines from the Life Cycle Assessment analysis is proposed within the paper. Several eco-design actions were put into practice to reduce the environmental issues in each phase of the life cycle from the materials used, the manufacturing processes as well as the product geometry to increase energy efficiency during the use. Concerning the materials and manufacturing phase, a novel design based on a different material (e.g., stainless steel) was developed to replace a mix of materials (i.e., copper and aluminum alloy). Concerning the use phase, the overall product efficiency was increased allowing important savings in terms of gas/energy consumption, by the adoption of a novel design (e.g., spiral pipe). The new heat exchanger design shows better environmental performance in each Life Cycle Assessment indicator, saving more than 40% in CO2 emissions (Global Warming Potential) in the whole product life cycle.