Do you really need a cooker hood?
Boiling pots of water, frying cooking oils, simmering a fragrant meal – all of these things release particles into the air in your kitchen that linger and settle if you don't remove them.
A cooker hood sits above your hob and sucks up the airborne by-products of your cooking, either releasing them outside or filtering them out and recirculating clean air back into your kitchen.
But is it an unnecessary expense? Can you save money by simply opening a window instead?
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Cooker hood vs opening a window: which works better?
Cooker hoods can be expensive, space-consuming and tricky to install. For this reason, you might choose to simply open your windows when you boil and fry.
This age-old method isn't the worst idea, but it will leave odours, steam and airborne grease to settle in your kitchen. And in the winter, it will sap your heat and leave you shivering while you cook.
Generally speaking, a cooker hood will always do a much better job than an open window or a dehumidifier, but it depends on the circumstances.
| Open window | Cooker hood |
|---|---|
| Positioned away and to the side of your hob, the source of steam and grease. | Positioned directly above the source of steam and grease, meaning the hot air will naturally rise and funnel into it. |
| Gently releases steam as air travels from hot kitchen to colder exterior. But once the kitchen temperature matches the outdoors, this effect slows and the humidity creates condensation on surfaces. | Vigorously pulls air in through its built-in filters for as long as you have it on. |
| Causes your home’s temperature to plummet in winter. | Prevents cold draughts, improving your home’s efficiency by trading off a small operating bill against the bigger one of heating your home. |
As our table shows, there are good reasons to invest in a cooker hood. And the initial outlay is a lot more bearable when you measure the costs of water damage in your kitchen as well as the unpleasant effects of airborne oil hanging around.
Our guide to the best cooker hoods will help you find the right size and style for your kitchen.
Do cooker hoods reduce condensation?
They are supposed to. Cooker hoods are purpose-built to absorb the unwanted by-products of cooking and they're positioned in the best place to capture and remove steam, grease and odours.
However, lots of the cooker hoods we test struggle with extracting steam and condensation can consequently build up.
That's why it's a good idea to read our reviews to find models that can handle your culinary adventures without turning your kitchen into an unintended sauna.
Why is my cooker hood dripping with condensation?
Signs that a cooker hood is struggling to effectively extract steam are wet walls and surrounding surfaces, which could lead to mould developing. You may also notice water dripping off your cooker hood down on to your hob while you're cooking.
To test how well a cooker hood extracts steam, we heat up a pan of water on each cooking zone of a hob. When the humidity has reached 90%, we turn on the extractor fan to maximum and record how long it takes for the humidity to drop to 60%.
The majority of the cooker hoods we've tested struggle with steam extraction so you could find that condensation builds up in unwanted places or that your windows steam up more than usual if you’re cooking on a cold winter’s day.
Use the 'Steam extraction' filter on our cooker hood reviews to see which models cut it.
Do cooker hoods reduce kitchen grease?
As well as condensation, unextracted steam can also cause grease to settle, leaving the tops of your cabinets sticky with fat so your kitchen needs more regular deep-cleaning.
To test how effectively a cooker hood removes grease particles, we turn it onto its maximum setting, then drip a small amount of oil and water onto a hot pan for 30 minutes. We then leave the cooker hood on for a further 10 minutes and record how much grease has been captured by the filter.
Again, many of the models we've tested struggle at removing airborne cooking oil droplets, leaving the rest to eventually settle on your kitchen surfaces.
Use the 'Grease extraction' filter on our cooker hood reviews if you tend to fry a lot of food.
Do cooker hoods reduce smells?
The scent of dinner is nice to come home to, but it will overstay its welcome without good ventilation.
To find out whether a cooker hood can effectively banish cooking odours, we turn it on to its maximum setting, then fill a pan with water and heat it up on the hob. A strongly aromatic chemical (methyl-ethyl ketone) is dripped into the water over 30 minutes. Its aromatic concentration is measured every minute at four different points in the room to determine how effective the cooker hood is at extracting the smell.
A powerful cooker hood, set up and installed correctly, should have no problem removing smells. But less powerful cooker hoods will leave you with lingering odours.
Our test findings show that thankfully, many cooker hoods make easy work of reducing cooking odours in your kitchen.
Use the 'Odour extraction' filter on our cooker hood reviews to choose a cooker hood that cuts smells.
Is it illegal not to have a cooker hood?
According to the Building Regulations 2010, any new build kitchen should be provided with a means of mechanical extract ventilation. This could be an extractor fan (with a minimum extraction rate of 60 litres per second) or a cooker hood (with a minimum extraction rate of 30 litres per second).
However, if you were planning on fitting a recirculating cooker hood then, in this instance, you would also need to install an extractor fan.
When renovating a kitchen:
- If there is an existing cooker hood then it must be retained or replaced with either a new cooker hood or an extractor fan. If the existing cooker hood is a recirculating model, then you could replace it with another recirculating hood but if the existing hood is an externally extracting model, you must replace it with the same or add an additional extractor fan.
- If there is no existing mechanical ventilation then ventilation does not need to be installed unless the refurbishment is likely to make the kitchen less compliant, for example, if you add a larger hob. In this case, you should follow the rules for a new build kitchen.
Legalities aside, it is always advisable to install a cooker hood that vents to the outside as a means of extracting smoke and odours effectively and improving indoor air quality.
Alternatively, choose a venting hob equipped with downdraft extractor to ventilate while you cook. Discover the best venting hobs.
* Figures based on all cooker hood reviews on which.co.uk in July 2025.