Environmental impacts of heating and cooling upgrades, considering the decarbonisation of the electricity grid

Peukes, Ina Eileen

Abstract

Rising temperatures and higher energy costs have created the imperative for Australian households to reduce energy consumption via more efficient heating and cooling systems. These energy efficient systems could lower the overall environmental impacts as heating and cooling accounts for around 20 % to 50 % of total energy usage of residential buildings. Nonetheless, the often overlooked aspect of efficiency upgrades pertains to the embodied energy and whether it is offset by operational savings as well as decarbonisation of the electricity grid. This research endeavours to determine the environmental impacts of 61 ducted gas heating to more efficient ducted gas heating upgrades and 59 gas heating to electric reverse cycle air conditioning upgrades via a life cycle assessment. A reference ducted gas heater, gas heater and air conditioner were deconstructed and assessed on their material composition. The operational energy savings of one year prior and after were collected for all upgrades.
The results showed that there were differences between the chosen impact assessment methods and that for the ducted gas heating upgrades the operational energy savings had offset the embodied energy for all assessed impact categories except freshwater ecotoxicity and human toxicity (non-cancer). For the gas heating to reverse cycle air conditioning, the following impact categories were offset: climate change (short-term), fossil and nuclear energy use, mineral resources use and ozone layer depletion. However, climate change (long-term), photochemical oxidant formation, human toxicity (cancer) freshwater and terrestrial acidification, marine eutrophication, particulate matter formation, ionising radiation, water scarcity, land occupation and transformation (biodiversity) could only be offset with the decarbonisation of the electricity grid. Not-withstanding, human toxicity (non-cancer), freshwater ecotoxicity and eutrophication was not offset even with a complete decarbonisation of the electricity grid, as the impacts from the production stage were too high. Notwithstanding the limited effectiveness of full decarbonisation, it is worthwhile considering the materials used in the appliance to further lower the environmental impact.

Citation

Peukes, I. E. Environmental impacts of heating and cooling upgrades, considering the decarbonisation of the electricity grid. (Thesis). Edinburgh Napier University

• Thesis Type: Thesis
• Deposit Date: Sep 4, 2024
• Publicly Available Date: Sep 4, 2024
• DOI: https://doi.org/10.17869/enu.2024.3789801
• Award Date: Jul 5, 2024