This is particularly true when you live in an apartment! If you live in a flat and have a feeling that your cooker hood is not working, you should continue reading.
Can you imagine a cooker hood without an engine or a fan?
The problem with extractor hoods in flats with central ventilation is:
- you should not extract cooking fumes into a centralized ventilation system, AND
- for some reason – manufacturers invented a standard (EN13141) that allows them to install quite expensive “look-a-like” cooker hoods without fans. This is misleading for the users.
The solution is a real extractor hood (according to IEC61591) for each apartment with extraction to the outside.
In most apartments, ventilation is centralized, which makes the extractor hood just a chimney-shaped passive hood, catching the heated air that is drifting upwards from the stove. It is therefore not surprising…
that you - as a tenant - have noticed that turning your cooker hood on, does not make much of a difference apart from providing light.
The standard EN13141-3 bluntly says: “Ventilation for buildings — Performance testing of components/products for residential ventilation — Part 3: Range hoods for residential use without fan”…..
Part 3 of the building standard covering residential range hoods (EN13141-3) is specifically for designs without a fan.
Let's pause for a second. A range hood (European term for a cooker hood) without a fan? Without a motor?
Oh yes. You want a flat with a cooker hood. And you may think you get a cooker hood that works, but something else is more important: The risk of fire. The reason is simple.
If airborne grease and smoke leaves your kitchen directly into the long ducting of the central ventilation system, then the ventilation system will rapidly be filled with grease.
To avoid clogging up a centralized ventilation system with an extractor hood, there are 3 options. The first one is the one described above. The third option is the good one, because the cooker hood works well:
- Hoods without a motor that will let the air out of the kitchen REALLY SLOWLY, so that most grease will have time to deposit neatly in the grease filters. In other words, a “cooker hood” with no fan and no real extraction of the filthy air, which is the case according to EN13141-3. The air circulation levels will be as low as 130-270 m3/h which is just the average level for moving the air with normal basic room ventilation.
A real cooker hood according to IEC61591 extracts up to 650 m3/h at maximum level and more in boost.
- Hoods that recirculate the air back into the kitchen. In this case the air circulation is also low for the same reason as mentioned above. These recirculation hoods use carbon filters to eliminate some of the odours. It’s not a great solution, it’s not very efficient, the filters do not last long, and most tenants tend not to change the filters,. However, at least the ducting of the central ventilation stays clean.
- A real cooker hood for each flat (according to IEC 61591) with extraction to the outside. This is the future. At present, the solution is hardly ever used.
The optimum solution has ventilation outlets on the roof top. In modern buildings with a focus on energy efficiency and airtight construction methods it is important to have a vent that will let extra air in when the cooker hood is turned on. Each flat will have its own controlled airflow that takes the energy and the indoor climate into account and adjusts accordingly.
The test methods used in EN13141, In particular, Chapter 7 (“Performance testing of odour extraction” with "an odour extraction ≥ 75%“) does not make much sense in neither test procedure, nor interpretation of the results.
The standard was developed in Sweden many years ago, but the direct reference to the norm was abandoned there almost 25 years ago in 1996, when the Building Regulations decided to leave it out.
In Denmark, the building regulation team (December 2020) is updating the BR20 and discussing the role of EN13141.
Things take time but let us hope for progress in all of Europe 😉.