Do Kitchen Extractor Fans Need to Vent Outside

Do Kitchen Extractor Fans Need to Vent Outside

Do Kitchen Extractor Fans Need to Vent Outside

Ventilation is a key component to any home or building being free from mould whilst having access to clean air. This is especially true for a kitchen, but does all ventilation need to connect to the outside?

In this blog, we will answer the question ‘Do kitchen extractor fans need to vent outside?’

With new buildings being made to be as energy efficient as possible, and the UK aiming for 95% of its electricity usage to be low carbon by 2030, it is imperative to understand how we can make the most of our ventilation. This is where applications such as extractor fans and heat recovery ventilation units come in.

To prevent mould, fresh air should constantly be introduced into your dwelling daily, as it helps to regulate temperature and reduce condensation. Introducing fresh air can be as simple as having a ventilation routine, or installing extractors or MVHR units. Almost all of this is facilitated by ducting.

If I have a cooker hood do I also need an extractor fan in my kitchen?

Yes. For the best possible ventilation, having both a cooker hood and extractor fan is vital. Cooker hoods belong above a cooker, and are a larger extractor fan that serves to quickly remove rising steam, smoke and smells that occur from cooking.

Although they are powerful and large, a regular extractor fan works to extract any humidity that travels around the room. An extractor fan would be running for longer if you cook in a kitchen without using the cooker hood.

Does a cooker hood prevent mould?

In some cases, yes. Because cookers, whether they are electric or gas, can generate steam, the steam can collect on colder surfaces above and form condensation. If the condensation is not addressed it will eventually become mould.

A cooker hood bypasses the steam finding anywhere to settle, as the cooker hood instantly attracts the steam into the ducting and outside.

Mould explained

Mould, otherwise known as damp, is a fungus that grows on wet surfaces. Mould comes in a variety of colours: Black, Green, Brown, Grey and White. It can be difficult to identify mould by colour as it can occur in many shades. Some of the most common mould strains in the home are:

  • Black Mould – Also called Stachybotrys chartarum, Black mould is commonly found in bathrooms and wet rooms but can also occur on cold exterior walls in habitable rooms such as the bedroom or living room.
  • Cladosporium – Commonly found in bathrooms, under sinks, and around faucets but it can grow on surfaces like carpets, furniture, walls, and floors.

Mould reproduces from tiny spores. The spores float through the air and deposit on the surfaces. Under adequate temperature, moisture, and nutrient conditions, the spores can form new mould colonies.

If you have found mould in your home, you need to assess if this is your landlord’s responsibility (for example it could be from a leaking roof that needs repairing). Or if the dampness is caused by improper ventilation. To assess your options, click here.

Mould exposure is known to cause or exacerbate illness if you have a mould allergy. Ensuring your home is free from mould is critical in keeping occupants healthy and safe.

Do kitchen extractor fans need to vent outside?

Do kitchen extractor fans need to vent outside?

Yes. Any extractor fan needs to vent outside, if this does not happen, the humidity has nowhere to go and can end up creating an environment in which mould can thrive. The ducting between the extractor and the outdoor vent provides the extracted air and dust a clear passage to exit the home.

The coverings placed on the extractor unit and the outdoor vent mitigate an excessive loss of heat whilst not compromising the unit’s ability to extract the indoor air.

In instances of kitchens that are built away from a direct outdoor wall, longer ducting is used to facilitate extraction directly outside for either the kitchen extractor fan and/or cooker hood.

Alongside extractor fans, MVHR Units provide the same benefits as an extractor fan, whilst maintaining the indoor heat and replacing extracted air with fresh, filtered, outdoor air. MVHR Units are ideal for anyone looking to optimise the level of ventilation in their home.

Do all kitchens need ventilation?

Absolutely. A kitchen is a room in a home or building that sees regular usage, as a result, there will generally be activities that generate humidity, or steam. This includes cooking, cleaning with hot water, and even using the kettle and toaster!

Of course, the size and level of ventilation in the kitchen will determine if any condensation ends up settling on a surface.

A kitchen should always have an adequate level of ventilation that can remove humidity effectively relative to its size. For the best results, using your cooker hood when cooking, in addition to your extractor fan and opening the kitchen windows is the most effective method.

Is mould only made from bad ventilation?

No. Mould can also form as a result of wet surfaces that can occur as a result of leaking pipes. This can be particularly dangerous as mould’s ability to spread depends directly on how quickly the leak is addressed, if left too long, it can spread to other areas of the kitchen and house.

Can I get rid of mould in my house?

Can I get rid of mould in my house?

Yes. To be clear, ventilation is a preventative method for mould, it does not get rid of mould that has already formed. Depending on how the mould was formed, there may be more than one way to deal with it.

Mould can be removed from a surface using mould-cleaning products. This includes mould surface cleaners and anti-mould paint. If the cause of the mould was a result of poor ventilation, adopting a ventilation routine and updating your ventilation units will prevent the mould from returning.

However, if the mould occurs as a result of leaks or structural issues, this must be addressed, otherwise the mould will eventually return. Irrespective of updating ventilation, if water is still setting within the building structure from the outside, it will eventually create mould. This is also true of internal leaks due to faulty piping.

Can I get mould from my neighbours?

If you live in a flat complex, semi-detached or terraced home, there is a chance of mould spreading from a neighbour’s home to yours. However, this depends on the severity of their mould problem, and what caused it.

If your neighbour’s piping is damaged, that can cause mould to develop if the leak finds its way to your home. Although you can’t control the measures your neighbour takes when it comes to ventilation, ensuring your home is in order is the best way to distinguish if mould is coming from your home or theirs.

Where to find kitchen extractor fans

Where to find kitchen extractor fans

At I-Sells, all things ventilation and ducting related is our speciality, we are here to answer the questions we know are common for those new to HVAC and what it encompasses.

We at I-Sells endeavour to ensure our customers have all the information they require before investing in our mould solutions. Be sure to visit our blog page to learn about the vast array of factors and issues surrounding ventilation, mould, condensation, and much more.

We hope to have answered the question ‘Do kitchen extractor fans need to vent outside?’

We understand you may have more questions, do not hesitate to contact us for more information about whatever you need our help with. If you’d like to email us, click here. For other contact options, see below:

Call us on 020 8463 9696

Visit us at our showroom:


Monday – Friday: 8:00 am to 5:30 pm

Saturday: 9:00 am to 12:00 pm

Sunday: Closed

15 St John’s Parade

Sidcup, Kent

DA14 6ES

United Kingdom

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