Fridges: How we test fridges

Fresh food inside of a fridge

Which? tests reveal the best fridges

Which? fridge tests

A great fridge will chill your groceries fast to keep them fresher for longer, and keep food at a consistent temperature when your kitchen heats up or cools down. It will run quietly, offer plenty of useable storage space, and won't add a fortune to your energy bills.

To find the models that fit this bill, we carry out more than 200 checks, measurements and tests on each fridge at our temperature-controlled labs.

To see the Which? verdict on the latest fridges, head straight to our fridge reviews.

Fridge cooling power

The faster your groceries chill to below 5°C the longer they’ll last and the more nutrients they’ll retain. To challenge fridges, we set the room temperature to 25°C and part-fill the compartments with gel packs to simulate food already stored inside.

We then add a light load of gel packs – roughly equivalent in size to a small fresh-food shop – to the fridge and record the time taken for them to reach 5°C.

Can you trust the fridge temperature?

We test fridges to check they will keep your food safely chilled 24/7. But room temperatures can vary widely – over the course of a day and at different times of the year. So we raise the temperature in our test chamber to 32°C and see whether the gel packs inside remain at the required 0-5°C. We then lower the room temperature to a chilly 10°C and re-check the temperature of the gel packs.

We also record the temperature of gel packs on the top, middle and bottom shelves and check how much the temperature varies - if your fridge doesn’t cool evenly across all of the shelves it could have warm pockets spots or icy patches, which could cause your food to spoil.

thermostat 2

We test whether the thermostat will accurately set your fridge running at 0-5°C 

Can you trust the fridge thermostat?

Keeping your food chilled between 0-5°C is crucial – as these temperatures will keep your food fresher for longer and help prevent harmful bacteria from growing.

When you’re setting up your fridge in your kitchen for the first time, most instruction manuals will recommend a thermostat setting. We test how accurate these are by following the instructions and recording the temperature of gel packs in both compartments.

The best appliances will chill to perfect temperatures as soon as you’ve set them up. But the worst are way off - leaving food too warm and meaning you’d need to use a fridge thermometer to get the running temperature right.

Fridge running costs

Running a fridge can be pricey – because it’s always switched on you will constantly pay to power it. We measure how much energy each fridge uses to keep cool over 24 hours, as well as how much it uses to chill fresh food, to calculate what this will add to your energy bill. Check out the specification tab for each fridge review to see how much it costs to run each year.

And to see whether a fridge is cheap to run for its size, we also rate its energy use against the amount of useable storage space it offers (see below).

Fridge storage space

The more storage space inside your fridge, the more groceries you can pack away and the less frequently you’ll need to shop. But two appliances with the same external size might have more than 20% difference in useable space due to differences in design.

We measure storage space with all of the storage features in place and don’t count any wasted areas. Our sizes give a more realistic indication of the amount of space you can actually use for storing groceries. Manufacturers’ claimed capacities are usually measured with all of the shelves, drawers and door racks taken out.

Ease of use and cleaning

Some fridges are easier to set up and use than others. We rate the type of display, position of the thermostat control and how easy it is to adjust, and whether it comes with a quick-chill or door-open alarm.

We also rate how sturdy the shelves, drawers and/or compartments are, the quality of the storage features and how easy the appliance is to clean. In total, we carry out 40 ease-of-use checks and tests on each fridge.

We use gel packs and temperature probes to test cooling speed

Fridge  scores explained

Fridge total test scores ignore price and are based on: 

  • Accuracy of recommended thermostat setting 10%
  • Temperature stability during everyday use 15%
  • Temperature stability in changing room temperatures 10%
  • Cooling speed 30%
  • Energy use 20%
  • Ease of use and cleaning 10%
  • Noise 5%

Fridge Best Buys

A fridge needs to score 69% or above in our tough tests to qualify as a Best Buy.

Which? refrigeration testing

We constantly improve our fridge tests to ensure only the very best models are Best Buys. This means that newer models have been tested and scored in a slightly different way compared with older models.

The section below outlines the testing and score changes made in the past five years. You can see when each fridge was tested under the ‘Full specification’ tab in each review. While the results for all fridges don't directly correspond you can still compare them generally, and each score gives a very good indication of the overall performance of each fridge.

Fridges tested before 2012

To see how quickly fridges could chill the contents of a weekly shop, we used a larger load of gel packs in our cooling speed tests. We also used an ambient room temperature of 20°C for the cooling speed and energy use tests.
 
The score is based on: Temperature stability and evenness (50%), cooling speed (10%), accuracy of thermostat (10%), energy use (10%), ease of use and cleaning (10%) and noise and vibration (10%).

Fridges tested 2012 – 2014

A survey of Which? members (August 2011) revealed more than 90% add fresh groceries to their fridge several times a week, and most keep it nearly full most of the time. We changed our cooling speed test to match this habit more closely by adding a lighter load of gel packs and by making sure the fridge is already nearly full, relative to its size.

We also raised the typical ‘room’ temperature in our test chamber from 20°C to 25°C to see how well each appliance keeps cool when it’s forced to use more energy - just as it is in your kitchen when you're cooking and when the fridge door is opened and closed repeatedly.

The score is based on: temperature stability and evenness (45%), cooling speed (10%), accuracy of thermostat (10%), energy use (15%), ease of use and cleaning (10%) and noise and vibration (10%).

Latest fridges tests - from 2014

To find the best fridges for keeping your groceries fresher for longer we’ve raised the amount that cooling speed contributes to the final score to 20%.

In light of rising energy costs, we now take into account the amount of power a fridge uses to chill fresh food – to give you a more accurate idea of how each model might impact on your energy bills and which are more energy efficient than others. We’ve also increased the amount that energy use contributes to the final score to 20%.

Because our energy calculations are now more accurate, running costs for models tested before and after 2014 shouldn’t be directly compared.

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