Connecting a cooker hood - how to do it right

Connecting a Kitchen Cooker Hood - Some Facts

Kitchen cooker hoods are divided into two main types.

The first type are extractors, which are connected to a ventilation system and remove all impurities generated during cooking from the kitchen and further outside the building. To connect a hood to an open circuit, we need access to a separate ventilation chimney that will vent steam, unpleasant odours, and harmful substances outside.

The second type of hood are recirculating hoods, devices that operate in a closed circuit. When using them without connecting to an exhaust duct, it is essential to ensure they have a carbon filter installed, which neutralises moisture and unpleasant odours.

It is recommended, where possible, to install the hood in an open mode, as an extractor connected to the chimney. This setup is generally quieter and more efficient.

Connecting a Kitchen Cooker Hood in Open Mode

If you have access to a separate exhaust duct and are looking for an efficient and quiet device - install the hood as an extractor. How to do this? Below are some key guidelines for the proper connection of a kitchen cooker hood.

Ducting for the Hood

One of the best solutions is to use a simple, smooth, and round duct. Many hood models connect to the ventilation system via a 15 cm (diameter 15 cm) duct, but this parameter should always be checked individually, as hoods have different outlet diameters on the motor, and the duct should match this. If the specific installation of your hood requires flat ducts (rectangular), the equivalent for a 150 mm diameter would be a 22 x 9 cm duct. Try to avoid reducing the duct diameter, as this will affect both the efficiency and noise level of the hood. Use rigid plastic ducts. Flexible ducts and spiro ducts are not recommended.

The ducts should be routed as short as possible and without unnecessary bends or right angles. We recommend routing them at an angle of up to 45° or with a gentle curve.

Avoid placing an elbow joint directly on the hood outlet if the ventilation grille in your kitchen is, for example, right next to the hood. Instead, run about 30 cm of ducting first. This will prevent the sudden airflow from the hood’s turbine from blowing back into the kitchen and ensure it is directed straight into the chimney.

Distance from the Cooker

The height at which we install the hood depends on two factors:

• The type of hood (angled wall-mounted, standard wall-mounted, island, etc.)

• The type of cooker (gas or electric)

Once you know which hood will be installed in your kitchen and which type of cooker you will use, simply check our post on at what height to install a kitchen hood, where exact dimensions are provided.

Installing the hood too close to a gas cooker can result in damage. Flames could melt the hood components made of plastic. On the other hand, if the hood is installed too far from the gas or electric hob, it may be less effective.

Hood Cover

The hood cover (also known as the chimney) is a metal shield (square, round, or rectangular) that conceals the ducting that removes fumes. Before connecting the kitchen hood, check its height and compare it with the height of your kitchen and the location where the ventilation grille is set up. Sometimes, it turns out that the duct needs to be additionally covered. Some models come with extension covers.

External Motor

An external turbine is a solution that makes the hood operate almost silently. The motor is installed outside the kitchen (in the attic, garage, or pantry), which means that when using the hood, you only hear a gentle airflow. This makes the hood not only quiet but also efficient, as there’s no hesitation to use it even on the highest speeds—something often avoided with hoods that generate over 50 dB noise on the first setting. With an external turbine, the boost function is as quiet as a mouse.

Hood Installed on the Wall, in a Cabinet, or on the Ceiling

A kitchen hood has some weight, so the wall where you plan to install it should be stable. It is recommended to use walls made of brick, concrete blocks, or concrete. Unfortunately, plasterboard walls can vibrate and resonate with the sounds of the hood’s motor, which can be annoying.

Built-in inserts and telescopic hoods are installed in a cabinet above the hob. Here, too, it is important to choose a suitable piece of furniture and correctly position the hood within it.
If you plan to install an island hood in a suspended ceiling, make sure its structure is strong and stable.

Connecting a Kitchen Hood in Closed Circuit Mode

Users opt for recirculating hoods for two main reasons: when there is no possibility to connect the hood with a duct to the ventilation system or when the decision is based on aesthetic reasons and a preference for a unit without an exhaust duct.

A recirculating hood is connected following the same principles, except for those concerning duct routing and the cover, as recirculating hoods do not require them. In this case, it is essential to install a carbon filter in the hood to enable it to function. Carbon filters wear out and need to be replaced periodically (usually every 3-6 months). Thanks to the active carbon pellets, they neutralise unpleasant odours (e.g., burnt food smells, unpleasant scents) and absorb greasy steam.

Proper installation of a kitchen hood is the key to ensuring its efficient and quiet operation. So, let's do it right.