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Most modern homes feature a dishwasher — up to 50 per cent of households in Australia — with many people running their dishwasher up to seven times per week. It is a useful, time-saving home appliance. A quality dishwasher should have a lifespan of at least 10 years, so it is worth doing your homework before you buy to ensure the dishwasher suits not only your household needs, but importantly that it also offers good energy- and water-efficient options. These can reduce the dishwasher's running costs significantly over its lifespan.
Most household appliances — including dishwashers — have been regulated by the Australian Federal Government (Australian Standards) for many years and feature easy to understand energy labelling. Under this program, all dishwashers featuring the Energy Star rating label have been tested for energy consumption and overall performance in relation to washing, drying, the dishwasher’s capacity, water consumption and water pressure. The energy rating scheme helps you to shop and compare with confidence knowing that certain standards have been met and measured.
The first step when choosing a dishwasher is to consider both its energy and water usage. Most of a dishwasher’s energy consumption relates to heating the water during the wash cycle, so this is an important consideration.
The hot water system in your home will determine what dishwasher will be energy efficient. If you use gas or solar hot water, then a dual water connection model, which can be connected to both the hot and cold water taps, is recommended to reduce your energy use and operating costs.
If you only have a cold water connection, the dishwasher will heat its own water during the washing cycle when necessary. This is the more energy-efficient option if you use an electric hot water system. Using only a hot water connection for your dishwasher will use the most energy out of these three connection options.
Energy Star ratings
The Energy Star label must be displayed on all dishwashers that are sold in Australia. This label shows the energy consumption for two water connections, supplying hot and cold water to the dishwasher.
The Energy Star label shows two measurements. An Energy Star rating measured out of six stars provides a quick visual gauge of the dishwasher’s energy efficiency. The label will also show the energy consumption of the dishwasher based on the manufacturer’s recommended connection. This measurement is displayed in the red box and is usually measured in kilowatt hours/year. This provides an estimate of the annual energy consumption (based on typical use in a home environment).
Tests show dishwashers consume less water than a hand wash in the sink, using up to five litres less water at approximately 16 litres per wash. In addition to the Energy Star rating, dishwashers display a water consumption star rating which shows the water efficiency and consumption (measured in litres per wash when set on a Normal program).
As a rule, make sure that the dishwasher has a 3.5 star energy and water rating. The addition of an extra star will reduce your running costs by up to 30 per cent.
Energy saving features
Many dishwashers offer a range of energy-saving features, for example special wash cycles (often labelled as eco or economy mode) that offer a shorter wash cycle and use less energy than the normal wash options.
New auto-sensing dishwasher options optimise the energy, water, time and temperature when washing your dishes. Additionally, some dishwashers may offer a half-load washing option. These features are designed to save on water and energy use. Another useful feature to consider is an economy drying mode, or running the dishwasher without using the power drying setting, as this will reduce energy use too.
It’s advisable to use your dishwasher efficiently by running it with a full load — load it based on the manufacturer’s instructions for best results — as well as cleaning and replacing the filter as directed.