Vented induction hobs explained: downdraft cooking for kitchen islands
Why the hob with built-in extraction has become the default choice for island and peninsula layouts — and how to choose between CATA’s 60cm and 77cm models.
A vented induction hob combines cooking zones with a built-in extraction system, drawing steam and cooking odours down through the hob surface rather than up through an overhead hood. The result is more efficient extraction, a cleaner kitchen, and a layout that works particularly well on kitchen islands where overhead ducting isn’t practical.
What are the advantages of an integrated hob extractor?
For a long time, a hob and a hood were two separate decisions. You picked a hob, then picked the chimney or ceiling extractor that lived above it. Vented induction hobs collapse that decision into one appliance and in doing so unlock layouts that were previously awkward or impossible — most obviously the clean-lined kitchen island with no obstruction overhead.
Three things are worth understanding before you compare models:
- Extraction efficiency. Capturing steam at the pan rim before it rises and disperses is far more effective than capturing it from a hood 65–75cm above.
- Layout freedom. No overhead extractor means uninterrupted sight lines across an island and no compromise on pendant lighting.
- Acoustic comfort. Because downdraft extraction is more efficient at source, the fan operates at lower speeds for the same cooking load — keeping noise lower in practice.
Capturing steam at the pan rim is far more efficient than capturing it after it has risen, mixed and spread across the room. — CATA UK product team
If you’re specifying for a clear-island layout with pendant lighting, the CATDD77CHF’s 770mm width provides proportionate visual scale across a wider island without creating dead zones at the hob edges.
How do vented hobs work?
Underneath the ceramic glass surface, two systems run in parallel. The induction coils generate an alternating magnetic field that heats ferrous cookware directly. Simultaneously, the SL1 motor beneath the hob pulls air down through a central grille at up to 630 m³/h across six fan speeds, with a boost mode for high-intensity cooking.
The extraction path
Air enters at the extraction grille, passes through a washable aluminium grease filter, then either a ceramic carbon filter if recirculating or directly to an external duct. Because the inlet sits flush with the cooking surface, vapour is captured before it crosses the sight line — which is what makes the appliance visually disappear on an island.
The CATA 700’s regenerative ceramic carbon filter blocks can be refreshed in an oven at 60°C for ten minutes rather than replaced outright, significantly reducing running costs.
Both CATA 700 models use a 32A connection (cable without plug) and require installation by a qualified electrician. Verify your island cabinet depth against the 170mm minimum installation height on detailed drawings before sign-off.
Recirculation vs. external ducting
External ducting gives the best extraction performance. It removes moisture from the kitchen entirely, which recirculation cannot do. However, the CATA 700’s regenerative ceramic carbon filter blocks offer a practical alternative where structural ducting is not feasible. For more detail on filter types and maintenance, see our guide to cooker hood carbon filters.
How do vented hobs work in a kitchen island setup?
Vented induction is at its best in two layouts: the true island (cooking zone in the middle of the room with no adjacent wall) and the peninsula (an island attached at one short end). Both are situations where running a chimney hood would either look heavy or require a costly ceiling recess or structural beam.
The ducting runs straight down through the island cabinet and into the floor void below, completely out of sight. There is nothing above the cooking surface except ceiling — and the open space between kitchen and living area remains uninterrupted.
What to check before specifying
- Cabinet depth. 170mm minimum installation height; verify on detailed drawings.
- Duct route. External ducting preferred — plan the run through the island plinth before cabinetry is finalised.
- Recirculation fallback. Where floor access is restricted, the ceramic carbon filter option requires no structural work.
- Cookware audit. Confirm pans are ferrous — a fridge magnet sticking firmly to the base is the quick test.
77cm for wider islands
The CATDD77CHF’s 770mm width suits larger island units, providing proportionate scale without dead zones at the hob edges. The 60cm CATDD60CHF is the right choice for standard kitchen worktop runs.
| Vented induction hob | Ceiling / island hood | |
|---|---|---|
| Extraction at source | ● Yes | ○ Above-pan |
| Ceiling clear? | ● Yes | ○ No |
| Max airflow | 630 m³/h | 750 m³/h |
| Noise at boost | 72 dB | 65–70 dB typical |
| Recirculation | ● Ceramic filter blocks | ● Charcoal filter kit |
| Min. install depth | 170 mm | n/a |
| Visual impact on island | Minimal | High |
Best vented hobs for modern UK kitchens: the CATA 700 range
The CATA 700 series is among the most capable vented induction hobs currently available in the UK. Both models share the same core specification: A++ energy rating, 7.4kW total power, 630m³/h extraction via the SL1 motor, four cooking zones including two flex zones, and a 170mm minimum installation height. The only material difference is width.
60cm Flex Vented Induction Hob
CATDD60CHF- 4 flex zones
- 630 m³/h
- 7.4 kW
77cm Flex Vented Induction Hob
CATDD77CHF- 4 flex zones
- 630 m³/h
- 7.4 kW
For technical installation requirements, the CATA 700 user handbook covers ducting specifications, cut-out dimensions, and electrical connection requirements in full. For current UK ventilation requirements, refer to Approved Document F on GOV.UK.
Frequently asked questions
Do vented hobs need external ducting, or can they recirculate?
Both options are available. External ducting exhausts air and moisture fully outside the home and gives the best performance. Where this isn’t feasible — in a flat or rented property, for example — the CATA 700 can recirculate using its included regenerative ceramic carbon filter blocks. These capture odours before the cleaned air returns to the kitchen, though they cannot remove moisture from the air.
How often do the filters need replacing?
The aluminium grease filter is reusable and dishwasher-safe — clean it roughly every four to six weeks. The regenerative ceramic carbon filter blocks do not need replacing in the conventional sense: place them in an oven at 60°C for ten minutes to restore their effectiveness. Running costs are negligible compared with systems using disposable carbon pads.
Is a vented hob harder to install than a standard induction hob?
The hob installs into a standard cut-out, but ducting needs to be routed from the underside. Both CATA 700 models use a 32A connection (cable without plug), so a qualified electrician is required in any case. For an island installation, ducting typically runs through the cabinet plinth and into a floor void. The 170mm minimum installation height fits within most standard island unit depths without modification.
What cookware works with a vented induction hob?
You need induction-compatible cookware — any pan with a ferromagnetic base. This covers most stainless steel and all cast iron. A quick test: if a fridge magnet sticks firmly to the pan base, it will work on induction. The CATA 700’s two flex zones (210×380mm each) accommodate oval casseroles, griddle pans, and fish kettles.
How noisy is a vented hob compared to an overhead cooker hood?
The CATA 700 runs at a maximum of 66dB on standard speeds and 72dB on boost. Many overhead hoods exceed these figures on equivalent extraction settings. Because downdraft extraction captures vapour more efficiently at source, the fan typically runs at lower speeds for everyday cooking — keeping noise lower in practice.
What is the difference between the CATDD60CHF and CATDD77CHF?
Both models share identical core specifications: 7.4kW total power, 630m³/h extraction, A++ energy rating, SL1 motor, six fan speeds plus boost, and four flex cooking zones. The only material difference is width — 590mm (60cm model, cut-out 560mm) versus 770mm (77cm model, cut-out 750mm). The 60cm suits standard kitchen layouts; the 77cm is the better choice for wider islands or larger cooking surfaces.
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