The ventilation system is loud and disturbing

Hello,

we moved into a KFW40 house some time ago. The landlord does a lot himself and was not finished with everything at the time of moving in. About 4 weeks ago, the ventilation system was installed and activated. Since that day, we have experienced significant noise disturbance.

The system switches between two levels depending on the humidity. At the first level, the noise is especially loud in the bathrooms and the kitchen. Examples: Having dinner in the kitchen with a conversation is very exhausting. When I stand in the hallway on the lower floor of the apartment, I can hear the ventilation in the upper bathroom.
When the system switches to the higher level, the noise can be heard clearly in all rooms. Then sleeping is not possible. In the kitchen, I measured almost 50 dB in the middle of the room with my phone.

Our landlord claims that these noises are completely normal and we only find them disturbing because the triple glazing shields the house so well.

It seems that the noise mainly comes from the inserts that are placed in the holes in the wall. When I remove them and look into the open hole, almost nothing can be heard even at the highest level. The inserts are made of stainless steel and honestly do not seem cheap but high quality.

My question is whether we are really too sensitive (and our neighbors below us as well) or if he somehow botched this. As I understand it, it cannot be that I build a house that is nice and quiet and then ruin it again with such a system. Unfortunately, I don’t know anyone with a house that has such a system, so I cannot compare.

Thank you very much for a professional opinion!

Best regards

Decentralized ventilation? Which manufacturer and which model? What control options do you have and can you turn it off completely at night?

So you live in a 2-story apartment in a new multi-family house. Is the ventilation system central or decentralized? Where are fans installed? If decentralized: How do your fans work - does one blow in and the other out, or does each fan alternate between blowing in and out? Can you control the fans manually (switch, remote control, app)?

I would at least expect a decentralized ventilation system in your multi-family house. Basically: Yes, you will always hear the fans, only on the lowest ventilation level (basic ventilation) are they inaudible during the day and only noticeable in silence in the apartment. At least it should be like this. Only a decentralized ventilation system can be almost silent. No ventilation system should be "loud," unless it is running at high power.

I also have a decentralized ventilation system. - manually controllable, so I can set whether a "power mode" turns on with increased humidity - not noticeable during basic ventilation in the daytime - can be turned off at night if needed - brightness sensor installed so the ventilation switches to minimum power in darkness if desired

You see, a lot is possible. So also from me the question: What model was installed and how is it set up?

Hi, thanks for your participation! It is a Maico 320 BET. According to the website, it is a central ventilation unit. Apart from turning it on and off, we can't do anything. He said we should preferably not adjust anything at all. Also, since the system has been running, we are not supposed to open the windows anymore because he said that then the humid air from outside comes in and the system would then especially increase its operation. In the living rooms except the bathroom and kitchen, the system blows air in. In the bathrooms and kitchen, it extracts air. It is a two-family house. We live on the 1st floor with attic about 130 m² with ~ 2.4 m ceiling height. Everything our landlord says sounds strange to me.

The system mentioned here is only responsible for our apartment. The neighbor in the apartment below has the same system for their apartment.

It seems that the noise mainly comes from the inserts that are placed in the holes in the wall. When I remove them and look into the open hole, almost nothing can be heard even at the highest level. The inserts are made of stainless steel and honestly do not seem cheap but rather high quality.

I have no idea about that, but what kind of inserts are those? Are there just some grids or somehow more?