Bathroom extractor fan in green tiled wall

Everything You Need to Know About Bathroom Ventilation

Given the nature of the space and what it's used for, your bathroom is by default a damp, humid place. It is therefore very important to ensure that all bathrooms in your home are well ventilated.

Proper bathroom ventilation will not only limit condensation, but it will also help prevent the appearance of mould and mildew which may in itself lead to nasty health implications. Excess build up of mould can lead to unsavoury respiratory problems such as asthma, as well as skin complaints including rashes. For more information on the negative effects of mould on your health, please visit the following links to the NHS and CDC websites.

What’s more, the implications of poor ventilation doesn't just affect your health. Appropriate bathroom ventilation also prevents any premature wearing of your bathroom itself, such as bathroom accessories, paint and plaster.  

Do you need an extractor fan in the bathroom?

bathroom extractors fans

All bathrooms require some source of ventilation, whether this is in the form of a bathroom extractor fan or an openable window. The UK regulations regarding just how much ventilation your bathroom needs are outlined in The Building Regulations Document F. However, this is a lengthy and in-depth document that is a pretty heavy read for the average homeowner!

So, to save you the headache of sifting through the official document, here are the essential requirements you need to know…

  • A UK bathroom must be ventilated by either a window or an extractor fan
  • If your bathroom has a toilet only, you are fine to use a window alone as your source of ventilation
  • In new-build bathrooms with a bath and shower, mechanical ventilation is required in the form of an extractor fan. This is because new-builds are built to be more airtight, so natural ventilation is much lower
  • The ventilation requirements for a bathroom are 15 litres per second/ 54m3 per hour

You might be wondering what the last point means. Basically, the 15l/s, or 54m3/hr, refers to the measurement of how much old air is replaced by new air. It is pretty much standard for bathroom exhaust fans to meet these requirements, though it should be stated in the product description of your fan; check before you choose it.  

If you have an old bathroom with only a window as a source of ventilation, it might still be a good idea to provide extra ventilation. If, for example, mould or dampness are persisting issues, a fan can help reduce their effects.

What are the benefits of a bathroom extractor fan?

A bathroom extractor fan is the easiest way to ensure that your bathroom meets air ventilation requirements. However, they also have benefits beyond your legal regulations. The main benefits of installing an extractor fan are:

  • To reduce condensation. Everyone can attest to the amount of steam a shower produces. An extractor fan minimises this.
  • To prevent mould. The condensation your shower creates can lead to a worse problem: mould. Proper ventilation can help stop it from forming.
  • To extend the life of your bathroom. Condensation and mould are both destructive forces in your bathroom. They can damage your bathroom fittings such as shower screens and curtains, mirrors, vanity units, and tiles. An extractor fan is a great line of defence against this.
  • To keep odours away. Finally, all that damp, stale air can lead to unpleasant smells in your bathroom. A fan helps keep your air nice and fresh!

If you have a wet room, you will find a bathroom fan especially useful. This is because water and steam can more easily disperse around the room and wreak their havoc! 

Installing a suitable form of ventilation ensures you can enjoy your bathroom at its best for as long as possible.

Read more: How to Remove Bathroom Mould

What different types of bathroom fans are there?

When it comes to choosing your bathroom fan, you may be wondering where to begin with all the different types available on the market. Which one is best to buy for your bathroom?

There are a few different types of extractor fan for you to be aware of. The most common are:

  • Axial - These connect directly through an external wall and are used when the air doesn't need to be moved long distances.
  • Centrifugal - These are designed for bathrooms that are not close to an external wall (over 1.5m away). They can move air long distances along their ducting, which means they have a more powerful extraction rate - and are often noisier. They are often fit in ceilings. 

You might also hear of inline fans. These are usually fitted in the ceiling and can be used for extra-long distances of 40 metres or more.

You will probably hear the term ‘ducting’ when searching for your extractor fan. This refers to the hose that carries the old air from inside to the external vent, similar to that you’d find in a tumble dryer. 

If your bathroom is a long distance from an external wall, or you are fitting it in the ceiling, you will require a longer 'duct run’. This also means you will need a more powerful fan - usually a centrifugal fan.

However, the most common type of extractor fan typically found in homes is the axial fan. 

Different types of extractor fan

Are bathroom extractor fans a standard size?

Domestic extractor fans tend to come in two sizes: 4 inch/100mm and 6 inch/150mm. This size refers to the size of the impeller (the revolving part inside the extractor fan that sucks the air out).

How do I size a bathroom extractor fan?

In order to know what size bathroom exhaust fan you need, refer to the cm3 (cubic metres squared) measurement of your fan.

If your bathroom is 100 square feet or less, you will need an extraction rate of at least 1cm cubed per square foot of room area.

So, for example, if your bathroom is 54 metres square, you will need a 54m3/hr fan.

It is generally a good idea to get a fan with a little more power than is required. Many fans offer a choice of two speeds and extraction rates, which means you can adjust it depending on how much steam is being created.

Which bathroom extractor fan is best for my home?

So, now you know the requirements of your bathroom extractor fan, it’s time to find the best one for your home. There are numerous options and features available to suit different needs and budgets.

Take a look at our overview below…

No-noise extractor fans

One of the most common complaints made about extractor fans is that they are too noisy. If this is a concern of yours, you might find our Xpelair Simply Silent range is best for you. These have been specially designed to reduce noise, thanks to their silent running ball bearing motors. The sound they make is measured on the decibel scale and can be as low as 30dB - the equivalent of a whisper.

Ideal for ensuite bathrooms where you don’t want a rattling fan keeping you up at night.

Over-shower extractor fans

Extractor fans work best when they are fitted as near as possible to the source of moisture in the air. For many people, this will be over their shower enclosure or bath. However, as bathroom fans are an electrical item, it is vital that you ensure you have the correct IP rating for this bathroom zone.

Our range of over-shower extractor fans have the required IP ratings to be used in zone one areas - this means anywhere in close proximity to water sources, including showers and baths

Over Shower Extractor Fans

Shop over shower extractor fans

Extractor fans with timers, sensors & cords

The array of timers and sensors on extractor fans make for some great extra touches for you to choose from.

One of the most useful is the humidity sensor - or ‘humidstat’. These automatically detect moisture in the air and switch themselves on, meaning you can rest assured that your bathroom is being taken care of.

Extractor fans with timers are also very popular. These keep running for a set number of minutes after they have been turned on. They are very practical as they continue to empty your room of steam after you have left the shower; without you worrying about having to go back and turn it off before dashing out to work! 

Timed fans are also ideal for those who want to connect theirs to their light switch. However, you can also find extractor fans with a built in light, is rewiring to your light switch seems like too much work.

If you don’t want your fan to decide for itself when to turn on and off, models with pull cords are available for you to control as you like.

Installing your bathroom extractor fan

Finally, you might be looking for some advice on how to install your extractor fan.

Read more: How to Fit an Extractor Fan

Here are some frequently asked questions and answers...

Where should you put an extractor fan?

In order for your fan to work at its best, there are a few conditions that are good to try and meet.

Firstly, mount your fan as high as possible on the wall. Secondly, try and position it as close to the main source of steam and condensation as you can - remember to check the IP rating is suitable. 

Finally, try and keep it away from the source of replacement air, such as a window - this ensures fresh air isn’t being sucked right back out of your room!

If it’s impossible for you to fit an extractor fan through your wall or ceiling, they can also be placed in windows. This is often a much easier job as it requires less building work. However, you will need to cut a hole in your glass, which is a tricky job for DIY beginners - contact a glazier if you are unsure.

Do bathroom exhaust fans have to be vented outside?

Yes, it is always a good idea to have your bathroom exhaust fan vent outside. Remember, the purpose of your extractor is to remove moisture from the air. If you simply deposit it in another room or attic, you are potentially just moving the problem to another area. 

To avoid dampness and mould entirely, make sure your fan exits outside.

How much does a bathroom extractor fan cost?

The amount it costs to install a new bathroom extractor fan depends on a few things, such as:

  • Which fan you buy
  • Whether you are replacing an old fan or fitting a new one
  • How straightforward forward your job is - is it simply being fit through an external wall? Or do you need longer ducting to reach your external venting point?

Bathroom extractor fans do vary significantly in cost. Some basic models can be bought for less than £20, while more specialist models can be closer to the £100 mark.

When it comes to fitting it, the cost will come down to the scale of the job. Replacing an old fan like-for-like may only take between two and four hours. If you require any rewiring or new building work, this could take much longer. 

Depending on the rate of your electrician and the length of the job, the cost for fitting could be anywhere between £150 - £200. 

All of the over shower extractor fans sold here at Plumbworld have a high IP (ingress protection) rating to ensure user safety and all come as a kit for easy installation. What's more, some of our over shower extractor fans are available with timers which continue to run after you’ve finished in the bathroom.

Shop extractor fans and bathroom electrical supplies from Plumbworld today!

If you're looking for further information on ventilation, extractor fans, or condensation, take a look at the following posts - How to Fit an Extractor Fan - Tackling Condensation in the Home - A Guide to Bathroom Heating.

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