Installing a range hood: extraction or recirculation mode, the complete guide

A well-chosen range hood clears the kitchen of cooking odours, steam and the grease that dirties walls and cabinets. Before buying, the first decision to make is the operating mode: extraction to the outside, which is more effective, or recirculation with a charcoal filter, which is simpler to install. Depending on your home's configuration, one or the other will be imposed, and this choice conditions the whole mounting.

Extraction or recirculation: which to choose?

• Extraction mode: the air is expelled outside through a duct, ideal in a house or a ground-floor flat
• Recirculation mode: the air passes through an activated charcoal filter then is returned to the room, suited to kitchens with no access to the outside
• So-called mixed hoods accept both modes, depending on the filter and duct kit installed
• Extraction mode is generally more effective and quieter: it never falls short on performance
• Recirculation requires regularly replacing the charcoal filter, so budget for an annual cost

In a flat, except in particular cases, extraction is rarely possible through the facade and recirculation becomes the solution. This mode works well, but the effectiveness depends on the quality of the activated charcoal and the replacement frequency: allow a change every 4 to 6 months for regular use, or as soon as odours persist. In a house, extraction through the roof or an exterior wall is almost always preferable, even if drilling through the wall or roof requires an extra day of work.

Choosing the right flow rate

A hood's power is measured in cubic metres of air per hour (m³/h). As a general rule, for a kitchen of 15 to 25 m² with 2.5 m of ceiling height, aim for a flow rate of at least 300 to 400 m³/h in normal use, more for a kitchen open onto the living room. A good compromise is to choose a hood more powerful than the calculated need and to use its lowest speed every day: it will be quieter and more effective than the reverse. The width of the hood must match that of the hob: 60 cm for a standard 60 cm cooktop, 90 cm for large cooktops.

The necessary tools

• The hood, its connection duct and its fixing kit
• Drill, masonry or plasterboard drill bits depending on the support, suitable wall anchors
• Spirit level, tape measure, pencil and screwdriver
• Rigid or flexible duct if the kit is not enough, and a hose clamp
• Ducting for extraction mode, charcoal filter and plenum spacer if necessary
• Voltage tester to check there is no power before the electrical connection

Mounting the hood step by step

1. Locate the axis of the cooking hob and mark the position of the hood with a spirit level, at about 65 to 75 cm above the hob.
2. Drill and insert the wall anchors, then fix the supplied wall bracket (clips, rails or telescopic).
3. Hang the hood on its bracket and lock it in place following the manufacturer's instructions.
4. Connect the extraction duct, fixing it with the clamp, or install the recirculation kit with the charcoal filter.
5. Connect the power supply, ideally on a dedicated socket at the planned location, switching off the power beforehand.
6. Check with the voltage tester that the circuit is dead before touching any wires.
7. Test the speeds and the lighting, then check there are no vibrations or play.

Maintenance to keep it effective

A dirty hood loses flow rate and quietness. Wash the metal grease filters in the dishwasher or by hand every 4 to 6 weeks, depending on how often you cook, and replace the charcoal filters in recirculation mode according to the manufacturer's recommendation. Regularly wipe the grilles and the underside of the hood, where grease accumulates. A clean filter preserves performance and reduces the fire risk linked to grease deposits.

The mistakes to avoid

• Installing the hood too high above the hob, which greatly reduces its effectiveness
• Choosing a hood narrower than the hob, which does not suck up all the steam
• Neglecting the fall of the extraction duct, which must rise slightly to avoid air returning
• Forgetting the charcoal filter in recirculation mode, making the hood useless against odours
• Connecting the electricity without switching off the circuit breaker, a serious risk of electrocution

Installing a kitchen range hood is a job within reach of a confident DIYer, especially in recirculation mode where no exterior drilling is needed. In extraction mode, drilling the wall or roof and running the duct may justify calling in a professional, as can the electrical connection if you have no experience in electrics. In all cases, switch off the power before touching any wires and check with a voltage tester. Allow 200 to 500 euros for a hood of decent quality, plus the cost of the duct and kit depending on your configuration.