How much water does a dishwasher use? Do dishwashers save water compared to washing dishes by hand? These are the inevitable questions for the environmentally conscious among us (who still want the convenience a dishwasher brings).
It certainly sounds like a lot of water when you hear it sloshing about during a cycle. But you’ll be pleased to know dishwashers don’t use as much water or energy as you might think – as long as they’re used efficiently.
To help you do your bit for the planet and save water around your home, we’ve put together this definitive guide to dishwashers vs. hand washing, with eco-friendly tips for both.
Dishwasher vs hand washing: which is better for the environment?
Let’s face it, this is what we all want to know. Dishwashers are convenient time savers, but do they save water and energy or waste it? Here’s everything you need to know about using the dishwasher vs. hand washing.
Do dishwashers use less water than washing up by hand?
The short answer to this is yes (usually). According to a leading manufacturer, a standard dishwasher uses around 9.5 litres of water per wash, while hand washing generally uses up to 60 litres. That’s a big difference.
A bit of maths will tell you using the dishwasher can save a whopping 85 per cent of water compared to washing dishes by hand. And switching from hand washing to a dishwasher can save up to 18,000 litres of water per year.
There are a few things to bear in mind here. First, dishwasher water usage varies depending on how old your machine is – older models are likely to be more wasteful. Second, the amount of water you use while hand washing will vary greatly depending on how you choose to hand wash – from keeping the tap running to filling a washing up bowl.
Are dishwashers more energy efficient than hand washing?
When it comes to energy efficiency, dishwashers also come out on top. A recent study by the School for Environment and Sustainability at the University of Michigan found that hand washing dishes produces double the amount of greenhouse gases over a 10-year period compared to using a dishwasher. (The greenhouse gases associated with hand washing dishes mostly come from the energy it takes to heat the water, so it does depend on your heating system.)
The caveat here is the same as for water usage – newer dishwashers are considerably more energy efficient than older models.
Which cleans better – the dishwasher or washing by hand?
Even on an eco setting, most dishwashers wash dishes at around 50ºc or more. That’s far hotter than water your hands could handle. Combine this with a great dishwasher detergent and the dishwasher is the clear winner here (as long as you load it properly).
How much does it cost to run a dishwasher every day vs. hand washing dishes?
The biggest cost of using a dishwasher is how much it adds to your energy and (possibly) water bills. We’ve already seen that dishwashers are usually more energy and water efficient than hand washing, so it’s safe to say that over the long term they’re more cost effective too.
That said, it’s super important to bear in mind that energy efficiency (and therefore running costs) depends on model. The Energy Saving Trust estimates dishwashers typically cost between £37 and £48 a year to run.
The most efficient dishwashers on the market have an A+++ rating and cost around £7 less to run per year than the lowest rated dishwashers that you can buy of the same size (and they use less water too).
Is hand washing ever the better choice?
The dishwasher has come up trumps so far, but let’s not forget some items aren’t dishwasher safe – it’s not time to hang up those rubber gloves just yet.
Most cookware, crockery and cutlery you buy these days will be dishwasher safe and they’ll likely have the dishwasher symbol on them (or on their packaging) to indicate as much. But make sure you check with the manufacturer of your dishwasher if you’re unclear about anything.
As a general guide, things that are unsuitable for a dishwasher include:
- certain types of plastic: always look out for dishwasher symbol on plastic items
- cast iron pans: if these are uncoated, they will rust
- antique china: the hot water could cause them to fade
- sharp knives: your knives will dull quicker in the dishwasher, so it’s still best to hand wash them
- wooden spoons: the wood will swell in the dishwasher and eventually crack
- aluminium pans: these react with the detergent solution and eventually discolour.