Financial feasibility of implementing an automated system to save the cold potable water that would be wasted at the beginning of a hot shower

ABSTRACT

In flats where there are gas water heaters, there is waste of water at the beginning of a shower due to the large lengths of pipes between the showerheads and heater. This paper analyses the financial feasibility of implementing an automated system that saves such water. This paper also shows how the system prevents such waste. In six flats, by collecting cold water at the beginning of a hot shower, it was observed that 9.28 litres of water are wasted until the water temperature reaches 30°C. A financial analysis was performed based on costs and the amount of water that would be saved. It was considered the installation of the system in one or two showerheads per flat for multi-family buildings of different heights. The installation of one or two systems per flat would lead to savings of, respectively, at least 2.13 litres and 4.14 litres of water per shower.

KEYWORDS:

• Tankless gas water heater
• water savings
• potable water storage tank
• cold water
• hot water
• financial feasibility

Acknowledgements

The first author is thankful for Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for the scholarship during the development of this research.

Additional information

Funding

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.