Open kitchen: exhaust or recirculation in controlled residential ventilation & KfW55

Thank you for the feedback, the majority is not less satisfied with the circulating air.

Here I have another question: What should I pay attention to when purchasing in terms of odor & grease removal? Are there any standards/certificates for the charcoal filters?

: you are one of the few here who decided on exhaust air. Do you have a controlled residential ventilation system in use? Have you planned separate supply air or how do you plan to implement this? How does it look with thermal losses of the wall box (when not in use - a hole remains a hole hence the question)

The controlled residential ventilation system plays no role in this. More critical are a chimney that operates with indoor air and the breach of the thermal envelope when a blower door test is conducted. The controlled residential ventilation system also does not care if a window is opened; it continues to function independently of that.

Of course, the controlled residential ventilation keeps running, but it really gets confused if you suddenly pull out a lot of air... We have recirculation in a closed kitchen, and that works very well. For some smells, I’m very glad they stay in the kitchen. We have the hood connected to the controlled residential ventilation; if the hood runs for a while on level 3, the ventilation also increases. If it’s an open kitchen that has a door to the living area leading to the hallway/stairs, recirculation would be enough for me. If I had everything open, and every smell wafted through the entire house, then I would probably tend toward exhaust air.

well, the controlled residential ventilation keeps running, but you really confuse it when you suddenly pull out a lot of air...

Sorry, but that’s not true.
How should the controlled residential ventilation be influenced by that, it doesn’t care at all.
The only thing that happens is that the air pulled out through the exhaust hood is drawn back in through the controlled residential ventilation. That’s it. Nothing happens and no one gets confused.

The only thing that happens is that the air pulled out by the extractor hood is drawn back in through the Controlled Residential Ventilation

But that would be a big fail in the planning.

How is the Controlled Residential Ventilation supposed to be influenced by that? It doesn't care at all... Nothing happens and nobody gets confused either.

Let's take a typical single-family house with 2 floors and Controlled Residential Ventilation, where the Controlled Residential Ventilation maybe pulls in and out 200 m3/h per floor. Now you come along and suddenly pull 800 m3/h of air out on the floor with the kitchen. That is like a bypass of the Controlled Residential Ventilation on the kitchen floor, because the Controlled Residential Ventilation simply can't keep up against that!

As a result, all rooms on the kitchen floor are practically no longer supplied/ventilated by the Controlled Residential Ventilation but first vented via the extractor hood higher up in the room while cold air flows in from outside below. And even on the other floor, the airflow, although not as drastic, is also affected.

Anyone who seriously cooks a lot will not be happy with recirculation. Whether it’s a hob or an extractor hood. Only exhaust air helps and getting rid of the stink. Alternatively, always open the window with both. That costs nothing and is just as effective!

I seriously cook a lot and enjoy it, nothing stinks with me and I have a recirculation ceiling hood. How exactly my tilted window should help against odors is not quite clear to me. Maybe don’t install the crappy recirculation hood for €99 with a paper filter, but something proper, then it will work out with fresh air. I have the Siemens LF26RH560 with 2 radial fans, 850 m³ on boost, and activated carbon filter + stainless steel grease filter.