For many years I’ve been dunking my hands in bowls of hot water scrubbing dishes and tea-stained cups to within an inch of their life, convinced I was cleaning the pots in the most energy efficient way.
However, since my other half convinced me that getting a dishwasher was the way forward in relieving us all of this chore, I’ve now come to appreciate that not only is my dishwasher a great time saver, it is also a great way to save energy and money too. But how so?
Firstly, let’s talk about the time it takes to wash dishes for a family of, say, 4 people in a week. We’re talking breakfast, lunch and dinner pots for all, with additional cups, glasses and cutlery etc., throughout the day, plus all of the cooking pots and pans used for each mealtime – that’s a lot of dishes, which means a lot of precious time taken out of your day, as much as 4 hours a week!
In fact, according to a study by Bonn University* a full load of 12 place settings took on average 60 minutes to wash up by hand, whereas, it only took 9 minutes to load and unload the same amount of dishes into a dishwasher. That’s a saving of 51 minutes!
Okay, so you may be convinced on the time saving, but surely a dishwasher uses up for more water than washing by hand? Well, the answer, of course, does depend on how each of us wash-up and together we can be divided into some distinct groups.
Firstly there are the perpetual washer-uppers, like my mum for example, who always likes an empty sink. You know the people I mean, those who whisk a cup from your hand a millisecond after you’ve drunk the last drop and before you can say, ‘can I have another’ it’s washed, buffed and back in the cupboard.
Then there are people like my old university ‘housemates’, who took great pleasure in seeing how high they could stack the day’s dishes on the drainer before gravity persuaded them it was time to clear away.
Finally, there are people similar to me; the ones who do the dishes straight after each mealtime, leave to drain and then pop them away when dry.
So, from washing up to 6 times a day, 3 or just one, water consumption will vary greatly across these groups. But don’t forget, you also have to factor in washing-up habits such as soaking, pre-rinsing, water replenishment and post rinsing and even washing up under continuously running tap water! As part of the Bonn University study I’ve already mentioned, they also looked at people’s different washing-up habits and their subsequent energy consumption and concluded that hand washing uses more water than dishwashing, you can read more of their study here.
Indeed, using the same study conditions of 12 place settings as above, washing by hand was found to use 49 litres of water, whereas a dishwasher washed the same load using only 13 litres.
If you want to see how much your hand washing costs in time, energy and money compared to the cost of managing a dishwasher check out this cool tool.
When you compare the energy used to hand wash (we’re talking kWh here, not physical energy) to using an appliance, you could be fooled into thinking that less kWh of energy is used. However, with the significant difference in the amount of water used (handwashing 49 litres, dishwasher 13 litres), the energy difference is 1.7kWh compared to 1.3kWh for the dishwasher.
According to Dishwashingexpert.co.uk most dishwashers manufactured since 1994 use less water per cycle than the equivalent required to wash up, because they recycle the water throughout the wash, with newer models heating only the amount of water they need – and being cold fill, the water is heated in the dishwasher itself, not in the household’s hot water tank or central heating system, where heat gets lost in transit.
The dishwasher for you
So if your days of hand washing dishes are over, how do you know which dishwasher is best for you? Fortunately there are many varieties of dishwashers available on the market to suit everyone’s needs, from counter top dishwashers, slimline, full size and my favourite, energy-efficient, A+ models, so the best way to find out which is best for you read up on dishwasher reviews.
And finally, to keep your dishwashing even greener, don’t forget to use the eco-settings, whenever possible only use your dishwasher when it is completely full and recycle your dishwashing product packaging.
*Professor Rainer Stamminger, Household and Appliance Technology at the Institute of Agricultural Engineering of the University of Bonn. 2007