Reducing Hot Water Usage

One of the easiest and most sensible ways to lower hot water costs is to reduce the amount of hot water being used. In most cases, this can be done with little or no initial cost, and with only minor changes in lifestyle. Some common-sense tips for reducing hot water use include:

Install low-flow showerheads and faucet aerators. These devices regulate and restrict water flow. Low-flow showerheads reduce flow rates from over 22 litres per minutes (lpm) to about 11 lpm, and only cost a few dollars to purchase and install. Hot water use for an average shower can be reduced from 220 litres to 110 litres. These showerheads often include a valve or pushbutton which can stop water flow while "soaping-up."

Take showers instead of baths. With a low-flow showerhead installed, showering may only use one-third the hot water of a bath.

Use the lowest temperature wash and rinse settings available on clothes washers and dishwashers. An average load of clothes uses 121 litres of water. Switching from hot washing to cold washing will save these 121 litres of hot water. Likewise, an automatic dishwasher typically uses 53 litres of hot water.

Operate clothes washers and dishwashers only when full.

Fix leaks in pipes and faucets. A leaky faucet can waste 11,000 litres or more every year.

Reducing water use in general; also result in lower water and sewage costs, and can help lengthen the life of your plumbing equipment. Operating washing equipment only when full will also lengthen equipment life.

Examples of Savings:

If you heat your water with an 80% efficient natural gas heater, it would take about 0.065 GJ of gas to heat 378 litres of water 33°C. That leaky faucet, wasting 11,000 litres a year, may only cost a few dollars to fix, but if left unrepaired would cost you $13 in fuel consumption (assuming $6.63/GJ).

If your water is heated electrically, it takes about 15 kWh to heat 378 litres of water 33°C. If you wash two loads of clothes per week, and can switch from hot to cold water, you could save over 12,500 litres of hot water per year. This would save you $55 a year (at $0.11/kWh).