How to buy the best bathroom extractor fan

A bathroom extractor fan removes moisture from the air, which is essential for keeping condensation and mould at bay. This guide will tell you everything you need to know when buying a bathroom extractor fan – from costs and features, to installation and where to buy. 

In our survey of 4,950 Which? members* who have bought a bathroom extractor fan, we found that many were happy to leave the decision over which product to buy to the bathroom installer – 40% said they spoke to a professional before deciding, while 32% did their own research into which fan to purchase. 

The more informed you are, the better decision you’ll make when choosing a fan, so read on to find out more.

Find out which retailers and products were rated highly by customers in our guide to the best and worst bathroom brands

Types of bathroom extractor fan

There are two main types of extractor fans used in bathrooms, axial and centrifugal. 

Axial bathroom extractor fans

Axial fans are the most common and have several advantages:

• Usually small and quiet, so better suited to smaller bathrooms
• Energy efficient
• Can be installed on external walls
• Suited to shorter duct runs of up to 2 or 3 metres.

Centrifugal bathroom extractor fans

Centrifugal fans are more powerful, but can be noisier as they use a drum blade. However, they are ideal for certain situations:

• Greater power makes them better suited to larger bathrooms
• Can be installed on the ceiling, which is important if the bathroom is more than 1.5 metres from an external wall
• Suited to longer or more complicated ducts.

The most common sizes for both types are 4-inch (100mm) or 6-inch (150mm) fans. A 4-inch fan will be powerful enough for a bathroom up to 9 sq.m, whereas anywhere larger will need the extra capabilities of a 6-inch fan.

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How much do bathroom extractor fans cost?

The cheapest extractor fan costs around £15, while those at the top end of the market cost nearer £250. 

The price will vary depending on the size of your bathroom and your exact requirements, but you should be able to find a very effective extractor fan for around £50 to £100. 

Best bathroom extractor fan features to look for

We asked Which? members what the most important features were when looking for a bathroom extractor fan. Their answers were:

• effectiveness at removing moisture 68%
• noise 41%
• price 12%
• style 8%.

Some other features worth thinking about include:

• Energy use - some fans can use as little as 5W, while others us as many as 35W, so pay attention to their energy consumption if you’re concerned about this.
• IPX rating - measures how well a device is protected against water and moisture. The number is the level of water protection, ranging from 0 to 8. The minimum requirement for a bathroom extractor fan is IPX4, but IPX5 is ideal for placement anywhere in the room.
• Integral PIR (Passive Infra Red) sensor - particularly useful if you forget to turn on the fan, or finding somewhere for a switch is tricky, this will automatically detect movement and switch the fan on.
• Humidistat - a sensor that measures air humidity levels, then turns the fan on when humidity rises about a set amount.

For further advice on preventing moisture from damaging your home, read our guide to how to stop condensation

How to install a bathroom extractor fan

Before trying to install a bathroom extractor fan yourself, make sure you have all the skills, tools and safety equipment required to complete the job properly and safely.

Then, follow these steps:

1. Prepare - decide where to install the fan. The ideal spot is accessible without any obstructions. Then cut the power supply before you begin work.
2. Make a hole - drill a small hole at the centre of where you want to install the fan. Then measure out the full extent of the unit and cut a large enough hole into the wall using something like a drywall saw.
3. Fit the fan housing - place the fan housing into the hole and use screws and wall anchors to secure it against the wall.
4. Set up the power - connect an electrical power cable from a power source to the fan. Make sure you follow all required electrical standards, and read the manufacturer’s instructions. 
5. Add ducting - if your model of fan requires ducting, join this to the fan housing and make sure it can run securely to the vent outside. 
6. Finish up - fit a vent cover on the wall vent hole outside, and run a final test to check the fan is working correctly.

Looking for other bathroom upgrades? Check out the best electric showers according to Which? tests

Can I install a bathroom extractor fan myself?

Only attempt to install a bathroom extractor fan if you feel confident about your DIY skills and understand exactly what to do at each stage. 

Don’t put yourself at risk of injury, during or after fitting. Also, remember that poor installation can affect functionality.

Our survey found that 41% of Which? members had a bathroom fitter install their bathroom extractor fan, while 28% used another professional (such as a plumber, builder or electrician). However, 22% managed to install it themselves. 

It should cost between £60 to £90 for installation of a bathroom extractor fan . 

Use Which? Trusted Traders to find a reliable tradesperson:

For further advice on finding a bathroom fitter, read our guide to bathroom installation

How to clean a bathroom extractor fan

It can be easy to overlook the extractor fan during routine bathroom cleaning, but it’s important to remove any buildup of dirt, dust, fibres or insects that may collect over time to keep it working optimally.

Follow these five easy steps to clean your bathroom extractor fan: 

1. Before you start cleaning, turn the power off.
2. Remove the cover from the fan and wash it with warm water and dish soap.
3. Dust around and inside the unit.
4. Dampen a cloth with a little soapy water and use it to wipe the fan blades.
5. Leave everything until it is completely dry, then put the cover back on.  

You don’t necessarily need to remove the fan motor, but it can allow for a deeper clean, particularly if you use a small vacuum cleaner.

For more cleaning advice, read our guide to bathroom maintenance

Do bathroom extractor fans use much electricity?

Bathroom extractor fans are usually inexpensive to run, as they typically only use 5 to 36 watts, depending on the style, model and make. 

If you’re concerned about the running cost, buy a modern model. as they're designed to be more energy efficient. 

Keep your bathroom windows open if possible, to help with ventilation and require less extractor fan use. 

Older extractor fans may wear as they age, becoming inefficient with dirty or damaged fan blades, and end up using more energy to remove the same level of moisture. 

Where to buy a bathroom extractor fan

• Amazon - primarily offers fans under £100, with plenty of options.
• B&Q - a huge selection, from an £18 basic fan to many in the £140 to £200 range, with features such as timers and sensors.
• Drench - a smaller offering, mostly stocking mid- to high-price range options.
• Extractorfanworld.co.uk - a specialist retailer of all types of fans, you can buy anything you need here, from a £15 to £250 model. 
• Plumbworld - a reasonably extensive offering, with various prices and options such as humidistat timers. 
• Screwfix - a general DIY retailer with a wide range of extractor fans at different levels of prices and features. 
• Toolstation - has a huge selection of extractor fans, covering many brands, prices and styles.

Read our guide on how to design a bathroom for decor ideas and advice on planning your bathroom, and find out how to update your bathroom on a budget

*Our research: An online survey of Which? members who purchased a bathroom extractor fan in the past 10 years, conducted in June 2024.