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?