tip
An average house using
electricity for water heating
generates about 4 tonnes of
greenhouse gas each year.
Using gas generates about
1.5 tonnes.
Water heating
Which appliance and fuel?
fact
Every 15 litres of hot water
used from an electric water
heater generates about one
kilogram of greenhouse gas.
- Buying an energy-efficient water heater that uses a low greenhouse impact fuel is a great start to saving greenhouse gases.
- Gas water heaters carry energy labels to help you choose an efficient model. Avoid units with continuous pilot lights and save $40 and 200 kilograms of greenhouse gas each year.
- When selecting a hot water system, ensure its size suits your needs—larger tanks lose more heat but supply more hot water.
- If you have a solar hot water service, switch off the booster in the sunny months.
- Electric hot water service units made since 1999 lose 30% less heat because of Minimum Energy Performance Standards.
Greenhouse gas emissions from an
electric HWS
(based on 140 litres usage per day)
Use less hot water
tip
Avoid 5 minutes of hot water
rinsing every day and save half a
tonne of greenhouse gas each year.
Water efficient taps can also save
hot water and greenhouse gas:
save up to a kilogram of
greenhouse gas for every five
minutes of tap use.
- Showers are the biggest user of hot water in most homes. Install a 3 star rated water-efficient showerhead and save more than half a tonne of greenhouse gas each year if you have an electric hot water service. They will also save many dollars in hot water bills and pay for themselves very quickly.
- Take shorter showers: you’ll save up to half a kilogram of greenhouse gas for every minute.
- Avoid using small amounts of hot water if cold water will do. Each time you turn on the hot water tap, a litre or more of cold water that had been heated but has cooled in the pipes runs down the sink before hot water is delivered. Doing this just 10 times a day will generate about 200 kilograms of greenhouse gas each year if you have electric hot water.
- Avoid rinsing dishes under running hot water: it uses far more hot water than putting the plug in and using some water in the sink—and often the job can be done by scraping or rinsing with cold water.
- If you’re going away for more than a few days, switch off your hot water systems and save 1.4 kilograms per day you are away.
Capture heat before it is lost
- Reduce heat losses from an electric storage heater by wrapping the tank with extra insulation: save up to half a tonne of greenhouse gas each year. An insulated outdoor unit will need to be protected from the weather.
Fix dripping hot taps: save up to
100 kilograms of greenhouse gas
each year for each tap.
- Fix dripping hot taps: save up to 100 kilograms of greenhouse gas each year for each tap.
- If the overflow pipe from a hot water service dumps more than a bucket of water each day, call a plumber and save hundreds of kilograms of greenhouse gas each year.
- When using a mixer tap for cold water, position the lever as far right as possible. Otherwise you will be wasting hot water, as most mixer taps begin blending hot water with cold as soon as they are moved from the ‘hard right’ position.
- If you have gas hot water, you save about one third of the amounts of greenhouse gas quoted above, which apply to electric hot water. Solar water heating can generate even lower greenhouse gas emissions.
Design for water and energy efficiency
- When installing a hot water service, position it so that pipes to outlets used a lot are as short as possible. This will minimise water, energy and time. Long pipes can waste thousands of litres of water and half a tonne of greenhouse gas each year.
- Avoid installing a continuously circulating hot water pipe loop. They waste large amounts of heat and cost a lot to run. If long pipes can’t be avoided, investigate the use of ‘on-demand’ pumps.
- Ensure exposed hot water pipes are well insulated, with insulation at least 10 millimetres thick.
Which hot water service will you buy?
Tonnes of greenhouse gas emissions
(average emissions for a medium-sized Sydney household)
