Development and Prototype Testing of a Smart Shower Meter

The Challenge

With permanent water restrictions in place, households are more accountable than ever when it comes to saving water. As showers account for the majority of household indoor water use, shower behaviour is a key area where more water efficient initiatives could be further developed and implemented to reduce overall water consumption in the home.

Although the shower is a place of significant discretionary water usage, there is little consumer insight into how much water is actually consumed.

Invetech, an Australian company that designs and engineers new products and custom automation, recognised an opportunity to develop a solution that delivers this insight and enables consumers to reduce their shower water consumption.

An idea was developed to provide families with a simple way to monitor the amount of water used during showers, with the ultimate aim of encouraging households to adopt more water-efficient shower behaviour.

Data from the project would not only have to demonstrate that shower water consumption was substantially reduced, but that the device would meet the following requirements:

  • be suitable for broad application across a large number of households
  • achieve savings that existing products cannot access
  • achieve an attractive payback time through the savings made; and
  • exhibit low barriers to purchase including low cost and easy householder installation.

The Project

As most people have a very poor idea of how much water they use in the shower, Invetech designed and developed the Smart Shower Meter, to provide a user-friendly, flexible way of monitoring and providing feedback on the amount of water used during a shower.

The device was tested to determine whether users, when given real-time feedback, would make significant reductions in their water usage.

Prototype meters were developed and installed in households throughout Melbourne for a six-month trial. Key features of the shower meter included:

  • easy to use user interface
  • automatic starting on the commencement of flow
  • water flow measurement
  • displayed time remaining to an allocated volume
  • programmable shower volume alarm
  • flashing indicator and audible buzzer
  • hold-off time between showers to prevent 'cheating'
  • water temperature measurement and display
  • estimation of the energy used to heat the shower water
  • sounding of a scald alarm if the water temperature exceeds 50C
  • battery powered – safe to use
  • shower information storage to allow water savings to be assessed.

At the conclusion of the trial, meters were recovered from the homes of the participating households and the recorded data was collated and analysed.

The Outcome

Lessons Learnt

Data from the shower meters showed that as a result of the interactive feedback given by the device, households achieved real and sustained water and energy savings.

Some households achieved savings by reducing their shower duration whilst others did so by reducing the flow rate. The majority of households reduced both the flow rate and the shower duration. These different responses illustrate the importance of providing customers with choices that allow individuals to establish their minimum water usage behaviour.

The average shower duration for participants was 7.24 minutes and the average shower volume 55.4 litres.

In households with a high-flow shower head the average water consumption per shower was

64.2 litres. This compares with 47.7 litres per shower for households with a low-flow shower head.

These results indicate that households with high-flow shower heads have a greater scope to save more water than those who have more water efficient low-flow shower heads. However, whilst the top three water saving households had high-flow shower heads, significant savings were also made by a number of households with low-flow shower heads.

Households reported that the metre was easy to use, and most indicated that they would purchase one if it was commercially available.

The Benefits

Results from the project demonstrate an average of 14.8 per cent reduction in shower water consumption among households who trialled the device for a six month period, regardless of whether they employed high or low flow shower heads. Some even reduced water usage by as much as 30 per cent.

Feedback from households showed that the Smart Shower Meter often generates a competitive dynamic between shower users that encourages more conservative water use.

"The Smart Shower Meter sets up a family dynamic," Invetech Senior Consultant, Simon English said, "each member doesn't want to be the one who uses the most water."

"The top 25 per cent of participating households each achieved projected annual water savings of more than 17 kilolitres," Mr English said.

Conserving water usage in the shower also has the potential for significant payback to the householder through:

  • reduced water heating costs – either gas or electricity
  • reduced potable water supply costs; and
  • reduced sewerage disposal costs.

Cost savings as high as $60 per annum could be achieved.

On average, the energy cost savings made up 44 per cent of the total household savings, which highlights the enhanced value of saving heated water within the home.

According to Mr English, a payback period of two to three years is likely for households that effectively used the shower meter to make a significant reduction in their shower water usage, and the most efficient water users would payback the device within just 18 months.

"Not only will users be able to make significant water savings and place less strain on the environment, but enjoy the financial savings that come with it."

Project Information

  • Project Round:
    2005
  • Project Status:
    Completed
  • Research Organisation:
    Invetech
  • Project Number:
    1021
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