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

Hello everyone,

we have installed a controlled residential ventilation Wolf CWL 400 and I want to realize a frame ventilation in the horizontal above the door leaf.

How many mm do I have to mill out over a length of 80 cm so that the required air volume also passes through? Is there some kind of calculation formula for an air cross-section?

The gap under the door is completely sufficient in 16 out of 17 cases.

I would be reluctant to be the 17th case. What is the formula here to check that?

As a rule of thumb, if you have 50% of the pipe cross-section under the door, then there are no problems. This corresponds, depending on the system, to a 2-3mm gap.

Door leaf with seals.

Door width > A 600 mm - B 700 mm - C 800 mm - D 900 mm - E 100 mm - F 1200 mm - G 1400 mm - H 1600 mm

that's what I was looking for. Thanks a lot!

In my specific case, I have 90cm doors and a maximum volume flow of 45m³/h. So I need a gap of 13mm. Assuming that 2-3mm are already present due to the normal installation, I would make 1cm by frame ventilation.

Is that okay? Can I generally assume 1cm for all frames, or should I actually go room by room and adjust the slots accordingly?


The diagram contradicts your statement now though