Journal
The topic of kitchen extraction can form a lengthy part of the bespoke kitchen design process, particularly in listed buildings where extraction routes are rarely straight forward. It can be a complex subject, particularly in historic buildings.
The principle goal with all kitchen extraction is to remove smells and smoke from the kitchen as efficiently and quietly as possible. Our ability to do this in listed buildings efficiently is determined by several factors including the size of the appliance being extracted over, the type of cooking being done on it, the length of the duct being used to carry the smells, the complexity of the ducting route and the location and size of the motor being used to move air along the duct.
LARGER PROPERTIES
We work in listed building of all sizes, from cottages to manor houses, and in the main, the larger the house the more complex the extraction. In larger houses, the number of people being catered for is greater and consequently the hob type being used is larger too, requiring beefier extraction to remove the greater amount of fumes and smells being produced.
Large extraction means a large duct, typically one duct at 250mm diameter or twin side by side ducts at 150mm diameter each. These ducts are often hard to weave through the fabric of an historic building, and they also need to exit the building in such a way that they are not seen, or at least do so in a way which is attractive and sympathetic to their listed architectural surroundings.
EXTERNALLY MOUNTED MOTOR
The location of the extractor motor is usually the first thing to consider. In an ideal world, the motor we specify for a kitchen extraction system will be externally mounted at the end of the duct. This is for two key reasons.
Firstly, an externally mounted kitchen extractor is quieter for those using the kitchen. Depending on the duct length, the noise in the kitchen will be limited to the sound of the air rushing through the grill itself. An externally mounted motor is also the most efficient method of air removal; pulling air through a duct is better than pushing it up it.
The difficulty with external motors in listed buildings is that they are large and not very attractive. They also need to be accessed regularly for servicing (which in the roof gully of an Elizabethan house is not practical). The motors are best located on a flat section of roof (not always available in a listed building) or on an external wall (which can create the illusion of a commercial extractor). Both options may also require listed building consent.
INLINE MOUNTED MOTOR
This is the next best option. The inline motor sits somewhere between the kitchen hood and the exit point, the advantage being that the noise of the motor is still kept apart from the kitchen. The downside is that the motor makes a noise elsewhere in the building, and if the extraction route is upwards, this can be in a bedroom. Again, the motor will also need to be accessible.
HOOD MOUNTED MOTOR
A motor located in an extractor hood is the most common approach but has its drawbacks. The noise levels in the kitchen are higher because the motor is located within the hood itself, and pushing air through a duct, particularly a longer one, is less efficient. However, servicing and maintenance is simplified.
In the UK, regulations governing kitchen extraction systems aim to maintain indoor air quality, reduce fire risks, and ensure compliance with environmental standards. Understanding these regulations is key. Part F of the UK Governments Building Regulations focuses on ventilation and is a critical document outlining the requirements for providing adequate means of ventilation to maintain indoor air quality.
TYPES OF EXTRACTOR HOODS
A cooker hood can operate in one of two modes:
DUCTED MODE – In this mode, the hood is connected to a duct that vents the air outside. This is effective for removing odours and moisture from the kitchen.
RECIRCULATING MODE – In this mode, the hood uses filters (usually charcoal filters) to clean the air before recirculating it back into the kitchen. This is useful when external venting is not possible.
There are several types of cooker hoods, each being suited to different kitchen layouts and aesthetic preferences.
CHIMNEY HOODS – Wall-mounted and typically have a classic design. Suitable for kitchens with a dedicated wall space and most common on period settings.
ISLAND HOODS – Designed for kitchens with cooking in a central island. We tend to design these less often as they hang from the ceiling and often become an obstacle or focal point.
INTEGRATED HOODS – Built into kitchen cabinets for a seamless look. Ideal for smaller kitchens where space is at a premium.
DOWNDRAFT OR COUNTER TOP EXTRACTION – Installed in the counter, or are integrated in to the hob itself, some rise up out of the worktop when in use.
SIZE OF KITCHEN EXTRACTORS
As a rule of thumb, a kitchen extractor hood should be at least as wide as the cooking area it is extracting over. In a listed building or period architectural setting, this often means extracting over a range such as an Everhot, Wolf or Lacanche.
Standard extractor widths are 60cm, 90cm, and 120cm but we often incorporate bespoke sizes in to our kitchen designs depending on the style of the room and the cooking area within the kitchen itself.
The fuel source and power of the appliance being extracted over is also worth noting; ranges such as Wolf have powerful burners which require extraction to match.
KITCHEN EXTRACTION IN ROOMS WITH OPEN FIRES
We have discussed the topic of running kitchen extraction in areas with open fires before. It is a problem not restricted to listed buildings, and the full blog can be read here.
To summarise, essentially extraction and open fires compete with one another, and if you are frying a steak on a Winter’s evening with an open fire nearby, and the extraction is operated, there is a real danger the extraction will pull the air from the chimney causing a down draft. There are ways to mitigate against this, and your first port of call should be a services engineer.
By taking into account the type, extraction rate, noise levels, filters, and other features, you can find the correct kitchen extraction for a listed building that not only keeps your kitchen air clean but also enhances the overall look and functionality of your cooking space. Happy cooking!
