Frame ventilation - How large does the air gap need to be?

Where does the table come from? It makes no physical sense at all. A standard pipe for a single-family house controlled residential ventilation has an inner diameter of 6 cm. That makes about 28 cm². Now such a pipe is also a few meters long, which results in huge friction losses. If you try to push 50m³/h through such a pipe, only a mild breeze blows out at the end. In contrast, with a door thickness of 3 cm, the losses are actually very limited. Neglecting all losses, you need 3mm per pipe of a controlled residential ventilation for a 90 cm door... the table doesn't even start there. Considering the losses, you are at most at the mentioned 50%, realistically and computationally it is probably significantly less.

I also found a table here:



Yesterday we routed a test frame. Due to the connectors on the right and left, we only reach a length of just over 80cm. The width is about 0.85cm. My carpenter was afraid the frame would become too unstable if he removed more.

The issue does not exist if the ventilation is appropriately sized. Then it is more a question of why 45m3/h should pass through. It becomes more interesting with glass doors or when drop seals are installed.

Doesn't interest the OP.
For that, it's better to listen to what's going on in the rooms...

Here are excerpts from my ventilation concept. I am not allowed to post external links and apparently uploading PDFs is not possible.




Wait! Your statement was that generally no overflow is needed at all because everything goes through the 2-3mm gap at the door anyway. There was no mention of incorrectly dimensioned air volumes. I assume you didn’t even look at my ventilation concept when it was still online here. And regarding the noise, I’m not worried; compared to shortened door leaves, frame ventilation is the better option.

By the way, I got my table from an Austrian site that deals exclusively with ventilation systems and was established together by the state of Salzburg, various energy associations, and an energy institute.
Additionally, the manufacturer explicitly points out the necessity of overflow through shortened door leaves or alternatives. Finished overflow valves are also available for purchase, so my approach can’t be completely wrong.

Maybe can comment on this again?

You have now cut your door frames, so any further discussion is unnecessary. You are building a normal single-family house; the ventilation systems are always designed the same way and are by no means rocket science. As describes it, the problem only exists in theory. You are supposed to open the doors occasionally, for example to pass through. Between most frequently used rooms in the house, there are no doors at all. The bedroom is actually only interesting between 0 and 6 a.m., and during those 6 hours the room will not explode, even if you tape the door shut.