Edinburgh Napier University

  Operational energy use in buildings, accounts for 28% of global energy demand. One method to reduce operational energy is upgrading old appliances to more efficient ones. In Australia, the most common residential heating type is reverse-cycle heating, followed by gas heating. This research paper aims to determine the energy balance resulting from a gas heating upgrade through a life cycle assessment (LCA). Extensive primary data was collected for operational energy performance of 61 ducted gas heating upgrades. To address the scarcity of data on material composition, one ducted gas heater was deconstructed and assessed in terms of material composition (types and weights). The comparison between embodied energy and operational energy savings allows us to establish whether operational energy savings offset the embodied energy incurred with the upgrade. The end of life stage of the old appliance, as well as the production, construction and use stage of the new appliance were assessed. Results show that operational energy savings offset the following impact categories: global warming, ozone layer depletion, aquatic acidification, non-renewable energy, and carcinogens. Only the mineral extraction is not offset by the operational energy savings. Results clearly demonstrate that operational energy savings outweigh the embodied energy and therefore contribute positively to the environment. This study is the first to focus on the LCA of building services through extensive primary data collection and a focus on a high number of appliances. This supports ongoing energy efficient upgrades in Australia and pave the way for further, similar studies to confirm or disprove these findings in other parts of the world.