An 80 cm hood does not extract more than a 60 cm one. The official fiches say so: the Bosch DWK67FN60 at 60 cm and the DWK87FN60 at 80 cm declare exactly the same figures, line by line, and so do their two Siemens twins. Four models, two brands, two widths, one single fiche. All that changes is the price, from 512.40 to 678.22 euro.
At PortosEunostos we downloaded twenty Bosch and Siemens product fiches and put them next to the manufacturer data. What comes out is that the number almost everybody buys a hood by, the cubic metres per hour of the intensive setting, is the one figure that compares nothing.
The short answer
The right order of questions is: where the air ends up, how much of it the hood moves at the point where it was measured, and how loudly. Width and energy class come later. And if you can duct outside, duct: across the eight fiches we compared, switching to recirculation always costs something, up to 39.6 per cent of the airflow and up to 9 decibels more.
Three airflow figures, and only one is comparable
Every hood declares at least three different airflow rates and the shop shows only one. The DWK67FN60 is a good example: 393.3 m³/h at the best efficiency point, 431 m³/h at maximum normal speed, 768 m³/h on the intensive setting.
The first is measured under EN 61591 at the point where the motor performs best, and it is the one the energy efficiency index is calculated on. The third is the highest, runs for a few minutes and travels through the fiche alongside the worst noise figure. Across the twenty fiches the airflow at the best efficiency point ranges from 195 to 414 m³/h: that is where the machines differ.
To see whether that is enough: a 12 square metre kitchen 2.70 metres high holds 32.4 cubic metres of air, which a 393 m³/h hood turns over twelve times in an hour and a 195 m³/h one about six.
Ducted or recirculating: the real cost
Ducted means the air leaves the house through a pipe; recirculating means it goes through an activated carbon filter and comes back into the kitchen. The models we looked at are all convertible, but conversion has a double price: in euro and in performance.
| Model | Ducted | Recirculating | Loss | Noise |
|---|---|---|---|---|
| DWK67FN60 | 431 m³/h | 427 m³/h | 0.9% | 56 to 64 dB |
| DLN53AA70 | 302 m³/h | 300 m³/h | 0.7% | 62 to 65 dB |
| DLN87AC50 | 600 m³/h | 580 m³/h | 3.3% | 61 to 69 dB |
| DBB67DP60 | 433 m³/h | 413 m³/h | 4.6% | 57 to 66 dB |
| DWB63BC60 | 400 m³/h | 361 m³/h | 9.8% | 67 to 68 dB |
| DWK87EM60 | 399 m³/h | 349 m³/h | 12.5% | 60 to 69 dB |
| DBB93BC60 | 384 m³/h | 291 m³/h | 24.2% | 65 to 66 dB |
| DFM064W55 | 394 m³/h | 238 m³/h | 39.6% | 68 to 71 dB |
Eight out of eight lose airflow and eight out of eight get louder. The worst case is also the cheapest of the group: the DFM064W55, 272.24 euro, loses almost four tenths of its air.
Then there is the real price. The recirculation kit is a separate accessory: in the catalogue, hood kits run from 72.47 to 679.68 euro and a replacement activated carbon filter costs between 79.30 and 91.00 euro, to be bought again periodically because it is the one part you cannot simply wash. The metal grease filter, on the other hand, goes in the dishwasher. And on wall hoods the chimney has to be taller in the recirculating version, because the air comes out of the top: on the DWK67FN60 it takes 790 to 1,083 mm against 753 to 996 for the ducted version.
One case where recirculation is not a free choice: with a gas hob, the standard ties any exemption from the permanent ventilation opening to a hood that actually discharges outside. We covered it when comparing induction and gas hobs.
Width is not power
The four twins from the opening, Bosch DWK67FN60 and DWK87FN60 and Siemens LC67KFN60 and LC87KFN60, all declare 431 m³/h, 768 on intensive, 56 dB and class A+. The extra twenty centimetres and the different badge are worth 165.82 euro and not one cubic metre of air.
The opposite is just as true. The 90 cm DBB93BC60 costs 318.20 euro, is class D and moves 200 m³/h at the best efficiency point; the 60 cm DBB67DP60 costs 573.25 euro, is class A+ and moves 340.1 there, 70 per cent more with thirty centimetres less. Width is there to cover the hob, not to pull air.
Noise decides whether you will use it
This is the figure that makes people switch the hood off halfway through cooking. In our sample the maximum normal speed ranges from 53 to 68 dB and reaches 71 when recirculating; on the intensive setting it runs from 65 to 73 dB, up to 76 when recirculating. Three decibels are a doubling of sound power: a loud hood ends up running on its lowest setting, where it moves half the air.
The four letters on the label
A hood fiche carries four classes, not one, and the big one is the least interesting: annual consumption in the sample goes from 27.2 to 90.6 kWh, which at today's 0.4343 euro per kWh is 27.54 euro of difference over a year between the best and the worst. How to read the label is in our energy label guide, and the bill, appliance by appliance, is here.
The other three matter far more:
fluid dynamic efficiency: how much air the hood moves per watt. Across the twenty fiches it goes from 9.4 to 37.1, a factor of four. It is the number that separates a hood that works from one that just hums;
grease filtering efficiency: from 60.9 to 90.2 per cent. What does not stay in the filter stays on your wall units, and the most expensive hood in the sample, 1,565.36 euro, has the worst value;
lighting: average illumination on the cooking surface ranges from 78 to 502 lux. The 174.00 euro model sits at 78 lux, class D, which means switching another light on anyway.
The measurements that decide first
minimum distance from the hob: on all eight Bosch models we opened it is 650 mm from a gas hob, and 430 to 550 mm from an electric or induction hob depending on the model;
outlet diameter: almost always 150 mm, 120 on some models. Connecting a 150 mm outlet to a 120 mm pipe throttles the airflow and adds noise, and flexible corrugated ducting makes both worse;
chimney height: declared with a minimum and a maximum and different between the two modes, it needs checking before you order.
PortosEunostos advice
What to check on the product. Download the product fiche required by Regulation 65/2014, which the manufacturer has to publish, and read four lines: airflow at the best efficiency point, fluid dynamic efficiency, noise at maximum speed, grease filtering. Then check whether the recirculation kit and the carbon filter are included.
How to judge the seller. Delivery times and costs for a bulky item, the returns policy, and whether filters and accessories of the same brand are in the catalogue: that is the part you will buy again over the years. The useful reviews talk about delivery and after-sales, not colour.
The Portos choice
If you can duct outside, that is the option that costs less and delivers more. Rank fluid dynamic efficiency, noise and grease filtering first, use width to cover the hob, and treat the energy class as the last criterion, because between the best and the worst there are 27 euro a year. If you have to recirculate, budget for the kit and the filter and pick a model with airflow to spare, not one at its limit.
Formats and price brackets can be seen among the hoods available on OpportunityCommerce, kits and filters included, and offers elsewhere can be compared on SniffaPrezzi.
Sources
Product fiches under Delegated Regulation (EU) No 65/2014 and information under Regulation (EU) No 66/2014 published by the manufacturer, for example DWK67FN60. Declared measurement methods: EN 61591, EN 60704-2-13, EN 50564.
Bosch, official product pages with the specifications in both modes, for example DWK67FN60 and DBB93BC60.
Bosch Italia, hood catalogue.
Prices recorded on OpportunityCommerce on 19 October 2026. Electricity: 0.4343 euro per kWh, ARERA, fourth quarter 2026, vulnerable customers on the regulated tariff.
