How we test cooker hoods
By Jane Darling
Discover how our in-depth cooker hood tests separate the best cooker hoods from the poor value models you should avoid.
What makes a Best Buy cooker hood?
We've tested cooker hoods from a range of big brands. Only those that excel at removing smells, grease and steam will win our recommendation. A Which? Best Buy cooker hood will eliminate odours in double-quick time and help keep your surfaces grease-free - all without making a racket.
We put each cooker hood through a set of rigorous lab tests, giving us the answers to the most important questions about these appliances, including:
- How well does the cooker hood remove steam?
- How good is the cooker hood at removing grease?
- How well does the cooker hood remove smells?
- How easy is it to use and clean?
- How noisy is it?
- What's the build quality like?
- Should I buy it?
How well does the cooker hood remove steam?
We test how well a cooker hood will remove steam from a kitchen by boiling four pans of water on the hob until humidity levels in our test chamber reach 90%. We then switch on the hood and record how quickly it reduces the humidity to 60%.
The worst simply aren’t powerful enough to clear the steam and can take nearly twice as long as the best to do the job - leaving your kitchen uncomfortably humid for longer.
How well does the cooker hood remove grease?
We see how well each cooker hood can clear the kind of grease produced when you're frying by dripping vegetable oil and water into a hot pan on a hob for 30 minutes.
This creates a horrible, greasy atmosphere and is a tough test for any hood. We weigh the cooker hood filters before the test, and again afterwards, and record how much grease has been captured.
The best cooker hoods are excellent and will capture around 80% of the grease. But the worst struggle to remove much more than 50%, which means you will be left with unpleasant, greasy kitchen surfaces.
How well does the cooker hood remove smells?
To test how well a hood removes smells, we use the pungent chemical methyl ethyl ketone, which smells like nail polish remover.
This is dripped with water into a hot pan to make our test chamber very smelly. We then record (using a flame ionization detector) how smelly the chamber is at four points around the room before the cooker hood is turned on, and again after the cooker hood has been on for 30 minutes.
A powerful cooker hood, set up and installed correctly, should have no problem in removing smells. But less powerful cooker hoods will leave you with lingering odours.
How easy is it to use and clean?
Firstly, we assess how easy each hood is to install and rate the clarity of the instructions designed to help you get going with your new hood.
We then see how easy the cooker hood is to use, taking into account variation in people's height, hand size and strength. A cooker hood with stiff or fiddly controls won't enhance your cooking experience, and we mark down any hoods that are awkward to use.
We also measure the brightness of the light and see how evenly it will light up your pots and pans.
If your cooker hood has hard-to-reach nooks and crannies or obvious places for cooking grime to collect, it'll be a pain to clean. We make the cooker hoods grubby, then assess just how easy each one is to clean, and whether it's awkward to get around any controls or edges. We also use an abrasive detergent to find out which ones can tolerate this without being damaged.
How noisy is it?
A cooker hood is basically a big fan, so it's bound to make a bit of noise. But some are a lot louder than others.
We record how noisy each cooker hood is in our noise chamber and listen out for any strange noises, rattles or vibrations. The cooker hoods we’ve tested range from a quiet 50 decibels - about equivalent to the hum of a refrigerator - to around 67 decibels, which is more like the noise you get from a vacuum cleaner or hairdryer.
If you have an open-plan kitchen where you'll be eating after you've cooked, or if you like to listen to the radio and chat while cooking, then opt for one of the hoods which scores four or more stars in our noise tests.
What's the build quality like?
Cooker hoods need to be attached to a wall, hung from the ceiling or built into a kitchen cabinet, so they must be well built. We check for build quality, sharp edges and finishing in our tests. The best cooker hoods feel solid on the outside and when changing the grease filter. A poor cooker hood has a flimsy feel.
Should I buy it?
All of the tests described above contribute to the overall test score a cooker hood achieves, which we then turn into a percentage.
However, some assessments are more important than others. You've told us that a cooker hood's most important tasks are the extraction of grease, odours and steam, so we give these a high weighting when calculating the overall score. The score is broken down as follows:
- 60% grease, odour and steam extraction
- 20% ease of use and cleaning
- 15% noise
- 5% build quality
A cooker hood needs 70% in our tests to become a Best Buy. Cooker hoods that score 45% or less are ones to avoid and are highlighted as Don't Buys.
Please note that all of our tests are undertaken in evacuation mode, where the steam and smells travel out of the kitchen via a duct. If you use a hood in recirculation mode, you may get different results.
Take a look through our top scoring cooker hoods in our cooker hood Best Buys.