There is a common question about how much water dishwashers use compared to washing by hand. There is confusion over which is the most economical and the most environmentally friendly method.
I’ve seen an advert claiming a Bosch dishwasher uses as little as 9 litres of water. It said it used, “a lot less water than washing up by hand saving as much as 50 litres for a similar load”. It’s a good advert for dishwashers in general. It points out that they can be more economical than washing by hand. However, as described later, it depends on how you wash dishes by hand.
The advert also describes how much more hygienic dishwashers are because they can wash in higher temperatures. Washing dishes by hand might score a lot more points though if we looked at the full environmental impact of a dishwasher.
Manufacturing, transporting and the impact of their factories and eventual disposal of the old dishwasher all impact the environment.
Is washing by hand quicker?
Another article quotes a manager at Hotpoint. He said that compared with washing the pots by hand you can save up to 75% of water, 65 % of energy, and 80% of time when using an efficient dishwasher.
The time saving factor claim is derived from comparing the time spent loading and unloading the dishwasher with physically washing them.
The time saving only comes from the fact that although the machine takes much longer to wash them you are free to use your time elsewhere. So washing by hand is quicker but uses up more of your time.
Dishwasher manufacturers are keen to get us to believe that it’s better to use a dishwasher. As ever with adverts they often tend to give a two dimensional view that favours their product.
The Advertising Standards Authority has just upheld a complaint about the Bosch dishwasher advert saying that, “the commercial did not make clear that in some cases washing up by hand could be more water-efficient than using a dishwasher”. Their water saving claims may only be true if the hand-washer has the hot tap running constantly to rinse dishes. However, if you don’t rinse the dishes individually under a running hot water tap, that probably uses less water than a dishwasher.
I think it’s at least safe to say that if used correctly, a dishwasher should be the best way to wash dishes – especially for more than 2 people. There’s a lot of research that (if trusted) shows dishwashers are cheaper to run than washing by hand. It all depends on exact circumstances though. To use a dishwasher efficiently you need to fill it up, and use the most appropriated cycle. I wonder if you are as surprised as I was to learn that 70% of British households still do not have a dishwasher?
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