chatelot16 wrote:if the blade is vertical the resistance is capped at 0,18 (m².K) / W at 25mm, finally it is already 0,17 at 15mm so we can say that it already capped at 15mm
The debate is progressing, but it is not yet completely correct amha:
- do not confuse, in this case convection takes place via the horizontal plane;
- it would therefore be better to say that: "it tops out from 25 mm" (therefore a value not to be exceeded on pain of reducing the effect until it is canceled, but no problem up to this value!)
And I was giving 1 inch, or 25,4mm, which is a perfect match. (and we also understand why this value would be reduced to 15 mm in a double glazing, due to the temperature differential that can be high between each window => increase in the "U" coefficient cf at high (therefore bad) surface exchange coefficient) . I believe that now it's clearer in the minds, thank you very much Chatelot, this notion of vertical VS horizontal exchange, really brings something.
And thanks also to Ahmed for pushing in the direction of this clarification, not so obvious at the start.