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

Hello everyone,

we are building with a central controlled residential ventilation system. I have often heard that the interior doors need to be shortened by about 1 cm after installation so that sufficient air circulation can take place.

Is that true? And if they are shortened, then there is an "open" edge at the bottom, on which no coating or edge banding is applied, is that not a problem?

How is it with you?

For us, the doors were also ordered to size. And yes: there must be a gap with controlled residential ventilation – in our execution plan, the directions in which the airflow takes place are also indicated. The architect explained that to us as well.

And yes: there must be a gap with controlled residential ventilation

No, it doesn't have to be. Overpressure can be ensured through - gap under the door - gap at the top between the frame and the wall - drop seal with overpressure opening - wall vent There may be other possibilities as well. Upon request, I am happy to link to a page that has been explaining this well for 10 years. If door gap, then it doesn’t have to be "we’ve always done it like this" 1 to 2 cm, rather the gap height is a function of the volume flow, the desired pressure loss, and the door width. (Overpressure openings are also a topic that, for my builder, seems to be completely new ops

Fa. Renson the Invisido system

Interesting, I didn’t know that. Do you know Mine drop seals from Planet?

No, I don’t know it, I’ll take a look. Thanks to you. Edit: I do know [Absenkungen], but not from Planet

Sent with the handheld device

Thanks for your tagging. So you have the "overflow opening" at the top of the doors. Did you do that yourselves? And in that area, do you also have no spray foam or anything, but is it really open? How satisfied are you with your solution?

However, the topic does not seem to be very well known among door manufacturers or door installers. So far, no one has asked us whether we had a controlled residential ventilation system, and with one, we mentioned it ourselves, and they did not know whether or how much needed to be considered.
In our execution plan, nothing is specified about flow directions or special door dimensions... (Although the flow directions are clear since we usually have supply or exhaust air depending on the room)

Thank you And in that area, you don't have any expanding foam or anything, but it's really open?

The door frames are only foamed in spots. By the way, I think the solution is quite good. The recesses are made quickly. Sent with the handheld device

We will slightly shift the frame forward/backward so that the shadow gap becomes a bit larger. It will then only be foamed very selectively, so that the overflow opening remains between the door and the wall.

Advantage: No light, no sound – and definitely no large gap between the door leaf and the floor, which in my opinion is simply unacceptable...