Open-plan kitchen-living rooms are popular: cooking, dining and living merge into one large space. The downside often only becomes apparent after a few months, when a fine film of grease covers shelves, window panes and curtains and the smell of frying still lingers in the sofa the next day. If you want to plan the cooker hood in an open-plan kitchen, you should decide early on which hood, which operating mode and which air routing suit the room.
In this guide, we explain why open kitchens place special demands on extraction, when extract air and when recirculation makes sense and how to choose the right hood type, size and mounting height. We also show what matters for the extract duct and wall box and what applies if there is a wood-burning stove in the same room. As of: October 2026.
Why open-plan kitchens place special demands on extraction
When frying and cooking, water vapour, grease aerosols and odours rise as a warm cloud. In a closed kitchen, this cloud stays in the room and can be separated from the living area by a door. In an open-plan kitchen, it spreads unhindered. Grease mist preferably settles on cool and textile surfaces, i.e. on windows, upholstered furniture and curtains.
The kitchen island is particularly demanding. A wall-mounted hood benefits from the rear wall guiding the cooking vapours upwards. Above the island, this guidance is missing, and even slight air movements from open windows, doors or people walking past deflect the cloud of steam sideways. An island hood therefore needs more surface area and a well-considered position to capture the vapours completely.
Extract air or recirculation in the open-plan kitchen?
An extractor hood carries steam, grease and odours outside. It is usually superior in effect because it also removes moisture from the room. However, it needs a wall penetration and a way for fresh air to flow in. A recirculation hood filters the air through grease filters and activated carbon and returns it to the room. It is easier to install and loses no heat in winter, but the moisture remains in the home. You can read how activated carbon works and when it needs replacing in the guide Activated carbon filters against odours.
| Criterion | Extract air | Recirculation |
|---|---|---|
| Moisture | is removed to the outside | remains in the room |
| Odour | removed very effectively | depends on the condition of the activated carbon |
| Installation | duct and wall box required | no wall penetration |
| Replacement air | supply air must be planned | not required |
In houses with mechanical ventilation, recirculation is often chosen because a powerful extractor hood disturbs the air balance of the system. The hood must never be connected to the ventilation system, as grease would contaminate the ducts and the heat exchanger. You can read more about comfort ventilation in the guide Planning mechanical ventilation with heat recovery. If you opt for recirculation, keep an eye on indoor humidity; you will find guide values under optimal humidity in the home.
Choosing the right hood type, size and mounting height
For open kitchens, the options are wall-mounted hoods, island hoods, ceiling extractors integrated into the ceiling and downdraft extractors that extract downwards directly at the hob. Ceiling extractors are unobtrusive but sit far from the cooking zone and only capture the vapours with a high air volume. Downdraft extractors are elegant but reach their limits with tall pots and heavy steam.
In any case, the hood should be wider than the hob. A common rule of thumb from kitchen planning: a 75 centimetre hob suits a 90 centimetre hood, and a 90 centimetre hob a 120 centimetre hood. Above an island, kitchen planners recommend more overhang than against a wall. For the air volume, an air change of six to twelve times the kitchen volume per hour is often assumed. In open spaces, the hood should be sized generously, because a large hood on a medium setting is quieter than a small one on its boost setting.
The mounting height is specified by the manufacturer, and its information takes precedence. Minimum distances are often around 65 centimetres above electric and induction hobs and up to 75 centimetres above gas hobs. If the hood hangs significantly higher, capture efficiency drops noticeably.
Extract duct, wall box and replacement air
The performance of an extractor hood stands or falls with the duct routing. Keep the route to the outside as short as possible and use few, wide bends. Ducts with a diameter of 125 or 150 millimetres are common; for many hoods, 150 millimetres makes sense, provided the appliance connection fits. Smooth-walled ducts offer less resistance than flexible hoses, which are mainly suitable for short connecting pieces.
At the end sits a wall box with a backdraught flap that closes when the hood is switched off and keeps cold air out. In well-insulated houses, insulated or motorised wall boxes are worthwhile so that the building envelope remains airtight. Replacement air is just as important: every volume of air extracted must be replaced. Without supply air, the performance of the hood drops significantly, so plan for a tilted window, a window contact switch or a supply air element.
Wood-burning stove and cooker hood: safety first
If there is a room-air-dependent wood-burning stove in the open-plan kitchen, planning becomes a safety issue. An extractor hood can create so much negative pressure that the draught in the chimney reverses and flue gases containing carbon monoxide enter the room. The German federal states' combustion ordinances only permit joint operation if no dangerous negative pressure arises. In practice, a negative pressure of no more than 4 pascals in the installation room is regarded as the limit, and approved safety devices are designed accordingly.
In practice, there are three solutions: a recirculation hood, a window contact switch that only enables the hood when the window is open, or a pressure monitor approved by the building authorities that switches off the hood if the negative pressure is too high. One example of such a device is the P4 Multi air pressure monitor from Erich Huber. In every case, agree the solution with the responsible chimney sweep.
Everyday operation and care
Even the best planning only works if the hood is used correctly. Switch it on a few minutes before cooking so that a stable airflow builds up, and let it run on after cooking. Many appliances offer a run-on function for this. When searing, select a higher setting early instead of reacting only when the cloud is already in the living area. Where possible, cook on the rear cooking zones, where a wall hood captures the vapour better.
Clean the grease filters at the intervals specified by the manufacturer; on many appliances a saturation indicator shows when it is time. How well a filter retains grease is shown by the grease filtering class on the energy label; read more in the guide grease filtering classes of cooker hoods. With recirculation, replacing the activated carbon is part of the routine, because saturated carbon no longer binds odours.
With extraction, it is worth checking the flap on the wall box. If it no longer closes properly, cold air flows into the kitchen and condensation can form in the duct in winter. A self-acting backdraft damper in the duct run can additionally prevent air from flowing back when the hood is switched off. One difference from catering remains: there are no requirements such as VDI 2052 for private kitchens; what counts are the manufacturer's instructions, building regulations and, with fireplaces, approval by the chimney sweep. How commercial kitchens are planned is shown in the guide Extract air or recirculation in the commercial kitchen.
Frequently asked questions
How much distance does the hood need from the hob?
The manufacturer's installation instructions are decisive. As a guide, around 65 centimetres above electric and induction hobs is common, and often somewhat more above gas hobs.
Is a downdraft extractor suitable for an open-plan kitchen?
For many households, yes, especially with induction and normal pot heights. With tall pots, large quantities of steam or frequent high-heat searing, a hood above the hob usually captures the vapours more reliably.
May I connect the cooker hood to the ventilation system?
No. Cooking vapours contain grease that would be deposited in the ducts and the heat exchanger. The hood works either in recirculation mode or with its own extract duct.
Do I absolutely need a recirculation hood with a wood-burning stove?
Not necessarily. An extractor hood is possible if a suitable safety device safeguards joint operation. Acceptance is carried out by the chimney sweep.
Conclusion
An open-plan kitchen requires more planning than a closed one, because grease mist and odours spread throughout the living area. Extractor hoods also remove moisture but need good duct routing and planned replacement air. Recirculation is simpler but requires well-maintained filters. Pay attention to sufficient hood size, the mounting height specified by the manufacturer and, with a wood-burning stove, an approved safety device. You will find ducts, fittings and flexible hoses for the extract routing in our categories Ventilation Ducts and Fittings and Flexible Hoses.
