Hood Information

You’ll enjoy a cleaner kitchen with a ducted hood – as steam, vapour, smoke and odours are quickly and efficiently removed.

Your home will benefit from this improved environment – free from the lingering fumes and smells associated with cooking.

Every BEST chimney hood is ultra efficient.

Superbly designed with modern living in mind – each of our high specification units is remarkably quiet during operation and BEST’s renowned reliability comes as standard.

General

BEST hoods help remove cooking smells, vapours and condensation and are designed for quiet operation.
As a general rule the hood should be activated before cooking commences. You will mainly use the lower and mid speeds during normal cooking, resorting to maximum speed when dealing with emergencies – such as burning the toast! Maximum speed is sometimes necessary when using all burners or when griddling meat as this can create excessive vapours.
We publish against each model the noise levels and the performance in cubic metres per hour for the maximum and minimum speeds to assist you when making comparisons with other makes.
The performance of a hood is extremely important and is normally measured in cubic metres per hour, i.e. how much air is moved. All BEST hoods have superior, powerful motors so it’s well worth making comparisons before making your decision.

Correct airflow levels

Choosing the appropriate extraction power of the hood (airflow) generally depends on the size of the kitchen and the kind of cooking that takes place there.
The air capacity of a hood is expressed in cubic metres/hour (m3/h), and represents the quantity of air which the hood is able to extract at maximum speed, measured according to international standard IEC EN 61591.
To calculate the appropriate airflow level for your kitchen, multiply the volume of your kitchen by ten. For example: if your kitchen is 3 metres wide, 5 metres long and 2.7 metres high, your calculation would be (3 x 5 x 2.7) = 40.5 x 10 = 405.
This would mean a hood with an extraction of 400 m3/h or more will achieve efficient ventilation of the room.
If you often cook fish, fried foods, grilled meat or other dishes which produce a large quantity of smoke, grease and odours, we advise that you select a hood with an even greater air capacity. BEST offer a wide choice of hoods with air flow levels of up 1000 m3/h.

Extraction

Ducting out or recycling?
It is always preferable to use BEST hoods as ducted models, i.e. ducted through an outside wall.
Air is drawn into the hood, fats are trapped by the grease filter. Odours, fumes and condensation are then expelled to the outside.
On certain models you can choose to install the hood as a ducted model or a recycling model – we would only recommend that a hood is used as a recycling model if it is impossible to duct out.
When using a hood as a recycling model, air is drawn into the hood and fats are trapped by the grease filter. The air then passes through charcoal filters to help absorb cooking odours and the purified air is recycled back into the kitchen.
It is realistic to assume that using a hood on recycling mode will circulate at least 30% less air than by ducting out – this is because the charcoal filters will restrict a certain amount of airflow. Charcoal filters are an optional extra unless otherwise indicated and will require replacing at least every 2/3 months or earlier with frequent use. Charcoal filters are not required if you duct out.
If a hood is used on recycling mode it will help reduce cooking odours but will not reduce steam or condensation. If you wish to reduce odours, steam and condensation, then you must duct out to expel these to the outside.

Height above hotplates – cooker hoods
Ideally the chimney hood should be positioned between 650mm to 750mm above the hotplate surface. Note that the chimney hood must not be positioned lower than 650mm.
On the Surf, Kite, Kite small, Sun, Mask and Azimuth the hood should be positioned as follows:
gas hob – 500mm above hotplate
electric hob – 400mm above hotplate

Ducting

Try to plan your hood and cooker onto an outside wall in the kitchen if this is at all possible. By doing this, you will minimise the length of the ducting and maximise the hood performance.
All BEST hoods have high extraction rates. Therefore, using the correct size ducting is of paramount importance.
The majority of BEST hoods have outlets which accept 150mm diameter. Do not be tempted to use reducers and fit 125mm or 100mm ducting as this will dramatically reduce performance and increase noise levels. Do not use concertina type expanding 150mm ducting.
When planning your ducting run try to keep the number of bends to a minimum as this will also help maximise the hood performance. We suggest that you always utilise Britannia rigid circular ducting or ‘Mega duct’ to optimise performance.
Note Ducting must not be connected to any existing ventilation or flue system that is being used for any other purpose.

Here are the maximum ducting lengths taking into account how many bends you require:
One 90° bend allows 4 metres of ducting
Two 90° bends allow 3 metres of ducting
Three 90° bends allow 2 metres of ducting

If longer ducting is needed the following should be borne in mind:-
10 metres and two 90° bends could mean a loss of efficiency of 7%
20 metres and two 90° bends could mean a loss of efficiency of 10%
10 metres and four 90° bends could mean a loss of efficiency of 10%
10 metres and three 90° bends could mean a loss of efficiency of 12%
20 metres and four 90° bends could mean a loss of efficiency of 18%

Ducted hood in the same room as a fossil fuel burning appliance
The following is a requirement of UK and European legislation and is in the interests of your safety.
If the room where a ducted cooker hood is to be installed also contains a fossil fuel burning appliance such as a gas or oil central heating boiler, then its flue must be of the room sealed or balanced flue type.
A ducted hood is not suitable for use in a room where any open flue is in use, as dangerous fumes of combustion can be sucked back into the room. This would include the following open flue appliances – central heating boilers, coal fires, log fires, gas fires, wood burning stoves, etc.
Therefore if you have an open flue fossil fuel burning appliance in your kitchen, you must select a hood that is capable of working on recycling mode.

Cooker hood – chimney kits
With the aid of the line drawings in the brochure and respecting the minimum distance between the cooker hotplate and underside of the hood, double check that everything will fit or ask your installer to check your sizes on your behalf. If you have any problems please contact the Britannia Technical Department who will be pleased to advise on all technical matters including coping with lower than average ceiling heights.

Canopy hood installations

These hoods are designed for fitting into the aperture of a canopy housing which can be of metal or cabinetry construction such as an over mantle arrangement. Sometimes a canopy hood is the ideal solution for positioning above a cooker that is sited in a disused chimney breast.
If you are having a canopy housing constructed, it will be beneficial to incorporate a catchment area into the underside of the housing – this would be a recess to hold and contain fumes, vapour, etc. before the canopy motor extracts these away.
If the underside of the canopy housing is totally flat, there is also a risk of fumes spilling around the front and/or sides of the canopy housing.
If the canopy housing is constructed in a combustible material it must be a minimum of 650 mm above the hotplate.