Controlled residential ventilation: Is an air gap under the doors required?

By the way, I have since spoken with our heating engineer; he said that apart from the "normal" air gap under the door, no special ventilation slots or gaps are needed because of the controlled residential ventilation. So we will try it this way for now, and in the worst case, we will have the doors trimmed slightly at the bottom. However, since not all doors are closed all day long, air exchange is certainly ensured this way as well.

It is always the question of how competent such a heating engineer is - how he calculated all of that for your house?

Yes, that is of course the question. But I have no desire to keep recalculating myself forever, he should know what he is selling and installing for us, I would say. The ventilation system was calculated by the manufacturer and the airflows were worked out, so they should be correct.

However, it is important on which assumption the air flows are based - I can understand the "no desire," but it doesn't help if it doesn't work or only works moderately, if there is noise, drafts, etc.

You will most likely just get a shrug from the HB anyway, and you will have to bear the damage - that's how it is in the construction business unfortunately...

Yes, you are kind of right, but I assume it is designed in a way that it fits. However, I will check again at home how exactly the calculations were, or if there are any assumptions included. Usually, such calculations also include reserves.

Did you recalculate and check everything on your side? What measures are you taking with the doors then?

We will slightly move the frame forward/backward so that the shadow gap becomes a bit larger. Then it will only be foamed very locally, so that the overflow opening remains between the door and the wall.

Advantage: No light, no sound – and certainly no large gap between the door leaf and the floor, which in my opinion is not acceptable at all...

We will do that – it fits for us so far because I had previously agreed on this with the ventilation guy.