How's it rated?

Energy efficiency ratings explained

You've probably seen these stickers on white goods in shops, and you'll have heard about A-rated appliances being the most efficient and so on – but what do these ratings actually mean?

Appliances are tested for efficiency in many different ways. From using a brick in an electric oven to test how much electricity is being used, to measuring the water consumption in a dishwasher, the tests and the resulting ratings offer useful information to help us make informed decisions when buying appliances.

Washing machines

A washing machine is a good example of an appliance that I use nearly every day. But how do these machines get tested? To make it fair, all manufacturers are tested in the same way. With washing machines, the machine is set on a cotton cycle at 60ºC with a full load and set to maximum spin. The machine is monitored for water consumption, and tested for energy use, cleanliness of wash, and dryness of spin results. 

Turning the wash temperature you use from 60ºC to 40ºC can save around 40% in running costs, while using a faster spin speed will reduce your drying time and therefore your tumble dryer costs.

Tumble dryers

As far as energy efficiency is concerned, tumble dryers have long been regarded as the evil twin to washing machines. Nonetheless, by choosing models with higher rpm speeds users can reduce both drying time and energy use. . Whilst most tumble dryers are C rated, condenser dryers are increasingly available in more energy-efficient models. For example 'A' rated condenser tumble dryers that use heat pump technology, such as the Siemens WT46W568GB, or our own John Lewis JLTDH17. Put simply, an A-rated machine will consume less energy per cycle than a 'C' rated model, but energy ratings indicate a band of performance and so this difference will vary depending on the particular model. To get the best from these energy-efficient dryers, keep them indoors (rather than in a garage or external utility room), and run them on full capacity.

Washer dryers

A boon when you're tight for space and can't fit it in a washing machine and tumble dryer, washer dryers give a similar performance to a washing machine when used on the wash cycle, but have a higher level of energy use than this when drying. Water consumption also increases as extra water is used to assist the drying cycle. This extra water is used to help create a ‘cold wall’, that draws steam away from the clothes. Most washer dryers are 'B' or 'C' rated, but 'A' rated versions are available, such as our JLWD1611 model. To reduce drying costs, go for the machine with the highest spin speed.

Dishwashers

Dishwashers can not only be great for saving time, but, depending on household circumstances, they can also often reduce bills when compared to washing by hand. They're checked for energy and water consumption, as well as wash and drying performance using the standard Economy 50ºC wash cycle, which pre-washes, washes, rinses and then dries. As with a washing machine, setting the appliance to lower temperatures and using an economy pre-set wash rather than an intensive one will help save on running costs.

Most dishwashers offer a quick wash of approximately 30 minutes, this quick wash can save you money by less water and energy. Additionally remember that the dishwasher will use the same amount of energy and water regardless of how full it is, Therefore waiting to turn the dishwasher on only once you have a full load will reduce the number of loads you need to do in a week saving you energy and water. Give it a try - you'll be surprised at how good the results are.

Fridges & freezers

Lastly, fridges and freezers are tested for energy consumption during the first 24 hours of operation. However, if it's a frost-free appliance then the energy efficiency rating tends to be more consistent or more accurate than in a non-frost free appliance. This is because energy efficiency deteriorates as ice builds up in the freezer compartment.

Advances in technology have enabled fridges and freezers to become so energy-efficient that a new class of energy efficiency has been introduced, meaning an A++ or even A+++ appliance is now available. To get the most efficient performance from your appliance, try turning up the temperature of your fridge when you’re on holiday and it’s empty, and remember to avoid leaving doors open any longer than necessary.

And the brick in the oven? According to Electrolux, a brick is placed in the oven at a set temperature, and as it heats up the energy consumption is monitored. The useable volume is then calculated to give the energy efficiency. So now you know!

Find out more about energy efficiency in electrical and technology products in our buying guide.