Fans

Hello everyone,

we are building a Kfw70 house, which also makes sense financially without a controlled residential ventilation system.

Now, like many others, we are torn back and forth about whether we really want to have a controlled residential ventilation system installed. It is specified, but the prices being asked are not insignificant... And a decentralized system also seems to be similarly expensive due to the number of rooms and additionally causes quite a few holes in the nice facade...

Now the heating engineer, who also installs ventilation systems, suggested installing fans in the exterior walls for the wet rooms (guest WC and bathroom), which are controlled by push button and/or humidity sensor and extract the moist air from the room.

In addition, an exhaust hood in the kitchen is also recommended.

What do you think of this?

Cost-wise, it really seems to be considerably cheaper.

It's certainly Stone Age technology, which contradicts a contemporary insulation project, but I would seriously consider it.

I also don't have controlled residential ventilation, but sometimes I would like to have a fan in the bathroom.

We are very satisfied with our Berbel exhaust hood. I can really recommend it. It truly creates clear air again.

Sylvia

The benefit is relatively low, isn't it? Then you can simply open the windows after showering? Or do you have no windows in the bathroom / toilet? If there is no heat recovery, I would skip the fans and just open the windows. Regarding the extractor hood: Do you have a chimney planned? If yes, an extractor hood becomes a bit more complicated again (pressure monitor, etc.).

No, a fireplace is not planned.

The advantage compared to opening a window seems to exist only if the fan starts due to the humidity sensor and then turns off again as soon as the humidity is no longer high; the window can then be forgotten...

If you are building nowadays, a controlled residential ventilation system should actually be mandatory. Can you really ventilate your airtight house regularly around the clock? By the way, your heating installer offers top prices if it is Elektro M. Ask other families in the building area. Almost everyone installs a ventilation system; the comfort gain is enormous. There are many posts on this topic here in the forum - mostly in favor of controlled residential ventilation!