Optimising Residential Water Heating System Performance to Minimise Water-energy Penalties

The energy consumption associated with domestic hot water supply services correspond to a significant portion of the total energy consumption of the urban water cycle. The objective of this study is to analyse the performance of domestic water heaters in the three largest cities of Australia (i.e. Sydney, Melbourne and Brisbane). The performance of systems was investigated undertaking a multi-parametric analysis, in which energy efficiency indicators (i.e. energy intensity and power peaks) were combined with level of service indicators (i.e. compliance rate with minimum temperature thresholds for end use points and hot water tanks). The operation of water heaters was modelled using the software EnergyPlus. Results demonstrate the need for a more holistic approach for the design and assessment of domestic water heaters taking into account not only the technology type to heat water, but also site specific aspects.