Kitchen Extractor Fans Explained: Ducted vs Recirculating, Sizing, and What You Actually Need
Let me start by saying something that might upset a few kitchen designers — the extractor fan is not just a decorative box above your hob. It is the hardest-working appliance in your kitchen, and getting it wrong is one of the most common kitchen planning mistakes I see.
If you are planning a new kitchen, you have probably spent weeks agonising over the cabinet colour and whether to go for a quartz or laminate worktop. But when it comes to the extractor, most people just point at the cheapest chimney hood in the brochure and move on.
I have been supplying kitchens to the trade and public across Greater Manchester for over 20 years. I can tell you right now: if you fit the wrong ventilation, your brand new kitchen will be covered in a thin layer of grease within six months.
Whether you are a developer fitting out a new build or a homeowner planning an extension, here is the honest, trade-insider truth about kitchen extractor fans.
Ducted vs Recirculating: The Big Decision
This is the first and most important choice you have to make.
A ducted extractor pulls the steam, grease, and cooking smells up through the hood, pushes them through a ducting pipe, and vents them straight out through an external wall.
A recirculating extractor pulls the air up, passes it through an aluminium grease filter and a carbon charcoal filter, and then blows that “clean” air back into your kitchen [1].
The Reality Check: Ducted extraction is vastly superior. It actually removes the moisture from the room, which stops damp and mould forming on your walls. Recirculating hoods do not remove moisture — they only filter smells and grease. If you are doing a heavy fry-up or boiling large pans of pasta, a recirculating hood will struggle to keep the room clear.
If your kitchen layout allows you to run a duct to an outside wall, you should absolutely do it. Recirculating hoods should only be used when ducting is physically impossible, such as in some flats or internal apartment kitchens. If you do use a recirculating hood, remember that the charcoal filters need replacing every six months — and nobody ever remembers to do it [1].
Getting the Size Right
There is a very simple rule in the kitchen trade: your extractor hood must be at least as wide as your hob.
If you have a standard 60cm hob, you need a 60cm hood. If you have upgraded to a 90cm hob, you must fit a 90cm hood [1].
The Reality Check: Never fit an extractor that is narrower than your hob. Steam and grease do not travel straight up; they fan outwards as they rise. If your hood is too narrow, the grease will simply bypass the filters and settle on your wall cabinets. In fact, many fitters prefer to oversize the hood — fitting a 90cm hood over a 60cm hob — to ensure maximum capture area.
Types of Extractor Fans
Once you know how you are venting the air and what size you need, you can choose the style. Here are the four main options we supply:
| Extractor Style | Best Used For | The Trade Verdict |
|---|---|---|
| Chimney Hood | Standard wall installations | The classic choice. Excellent performance for the price, but they do dominate the wall space. |
| Integrated / Canopy | Minimalist or handleless kitchens | Hidden inside a wall cabinet above the hob. Gives a completely seamless look to the kitchen run. |
| Ceiling Extractor | Open-plan rooms and islands | Built flush into the ceiling. Looks fantastic, but requires sufficient ceiling void space to house the motor and ducting. |
| Downdraft | Kitchen islands without ceiling space | Rises up from the worktop behind the hob. Very sleek, but pulling steam down against its natural upward flow requires a very powerful (and expensive) motor. |
The Power Rating (Extraction Rate)
Extractor power is measured in cubic metres per hour (m³/h). This tells you how much air the fan can move in 60 minutes.
To figure out what you need, calculate the volume of your kitchen (Length × Width × Height in metres) and multiply it by 10. A good extractor should be able to change the air in your kitchen ten times an hour.
The Reality Check: If you have a large, open-plan kitchen-diner, do not buy a cheap 300 m³/h extractor. It will sound like a jet engine and do absolutely nothing. You need to be looking at models rated at 600 m³/h or higher. Furthermore, if you are cooking on a gas hob, you generally need more extraction power than if you are using induction, as gas produces more ambient heat and combustion by-products.
The Final Verdict
Do not treat your extractor fan as an afterthought. A cheap, underpowered, recirculating hood will leave your brand new cabinets sticky and your house smelling of last night’s dinner.
If you can duct it outside, duct it. Make sure it is at least as wide as your hob, and check the m³/h rating before you buy.
If you are planning a new kitchen and want honest, practical advice on what will actually work in your space, we can help. We supply complete, rigid-built kitchens to the trade and public, usually within 10 working days. Give us a call, drop us an email, or visit our showroom in Oldham, Greater Manchester. Bring your measurements, and let’s get your project started.
Steve Ball
SJB Trade Kitchens
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