How to choose fixings for a hood or ventilation duct

Mounting brackets for commercial kitchen hoods and ventilation ductwork are chosen according to three simple criteria: the weight of the equipment to be supported, the duct diameter and the type of mounting surface available (wall, ceiling, steel structure or flat roof terrace). An insulated clip or a jubilee clip does not meet the same need as a heavy-duty load bracket: the former holds a duct along its length, the latter carries the weight of an extraction fan box or a wall console.

The threaded rods, clips, rails, brackets and suspension cables in the range allow the various elements of the installation to be fixed or suspended: hood, extract duct, rigid ductwork, fan box or ventilation accessories. In terms of parcel weight, items range from 200g (clips, suspension cables) up to 10kg for the standard hood assembly kit, a useful reference point for estimating parcel size before ordering.

Fixing ducts and ventilation ductwork

Ducts must be properly supported along the whole run. The duct diameter, its weight, its length and the installation layout determine the type and number of supports required. The insulated fixing clip, made in France, includes an anti-vibration solution that limits the transmission of vibration to the building structure, a real benefit when the fan runs all day. To simply clamp a duct with no particular insulation requirement, the jubilee clip (sold in a bag of 10) covers the everyday needs of a site.

To fit out a whole ductwork run rather than buying parts one by one, the fixings kit for 6 to 10m of ductwork brings together the fixings needed to support an average duct run, a genuine time saver whether in the workshop or on site.

Fixing a commercial kitchen hood or an extraction fan box

For a commercial kitchen hood, the fixing system is chosen according to its weight, its dimensions and the mounting surface available. A wall fixing can be supplemented with threaded rods or suspension cables where the installation layout requires it. The hood and fan box installation kit brings together threaded rods and fixings to suspend the whole unit without having to place multiple separate orders. The suspension cables with self-locking grips (sold in packs of 4) offer a practical alternative to a standard wall fixing, particularly when the ceiling already carries other services.

For a double-inlet centrifugal fan, the fixing frame and the support feet with anti-vibration mounts limit the transfer of vibration to the structure, a point often overlooked that can end up as noticeable background noise in the kitchen.

Fixing on a flat roof terrace and sealing wall penetrations

For ductwork installed on a flat roof terrace, the duct support foot for flat roofs (Ouestventil) stabilises the duct without a permanent fixing into the roof's waterproofing, useful on installations where you want to avoid puncturing the membrane. For wall penetrations and duct joints, the sealant cartridge ensures long-term performance, and the fire-rated expanding foam (Ouestventil, made in Europe) is different from the standard expanding insulation foam: the former provides a fire-stopping function on a wall penetration, the latter is a simple thermal or acoustic insulation product. Do not mix them up, they are not used for the same purpose.

Points to check before ordering

• The actual weight of the equipment to be fixed (hood, fan box, motor) to choose between a simple clip and a heavy-duty load bracket.
• The exact duct diameter, to compare against the diameter stated on each clip's product page.
• The type of mounting surface (solid wall, ceiling, steel structure, flat roof terrace), which determines the choice between a wall fixing, a strut mounting rail or a flat roof support foot.
• Whether a fire-stopping requirement applies to a wall penetration: check the fire regulations for your project before choosing between fire-rated foam and standard insulating foam.
• The number of fixing points needed over the total duct run, to work out the right quantity of clips or the appropriate fixings kit.

Need help choosing your fixings?

To advise you, let us know the equipment to be fixed, its dimensions and weight, and the type of mounting surface: wall, ceiling or steel structure. We can then point you towards the right mounting brackets and fixing accessories. To see these accessories fitted in practice, our YouTube channel has step-by-step installation tutorials. A useful reminder: VentilSoGood supplies the equipment but does not carry out installation, fitting remains the responsibility of a qualified professional.