Isolation in corks recovered?

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Obamot
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by Obamot » 26/05/13, 19:14

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.
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by chatelot16 » 26/05/13, 19:45

when we see the resistance go from 0,17 to 0,18 from 15 to 25mm we can say that these 10mm more really do not bring much

if this air gap is fixed between 2 walls, there is no need to break your head, you put a little more to be sure there is enough: the air costs nothing

on the other hand for a window, increasing the thickness increases the size and the price of the set ... no need to put too much to win the last figure

we also see the advantage of sharing the blade in 2: triple glazing: 2 blades of 10 are much better than a blade of 20

another trap with the double panes: the heat does not cross only by conduction and convection: it also crosses by radiation with completely different physical law: from temperatures to power 4: giving the thermal resistance of a window is almost absurd: this is only valid in a standard measurement condition representative of the average condition where there is a window ... this is completely false in the extreme temperature or radiation conditions
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by Obamot » 26/05/13, 22:21

chatelot16 wrote:when we see the resistance go from 0,17 to 0,18 [W / mK] from 15 to 25mm we can say that these 10mm more really do not bring much

Perhaps, but what I see above all is that at 25mm with a coef of 0,18 W / mK, the air gap is comparable to polyurethane foam (which takes over from 20 W / mK

It's still not bad, for a "compromise" solution ...!
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by Christophe » 27/05/13, 00:18

chatelot16 wrote:I had looked for figures a long time ago, and I had found that (...)


And this one: https://www.econologie.com/forums/isoler-des ... t8971.html ?
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by Christophe » 27/05/13, 00:22

Obamot wrote:Nada, niet, nothing ... it doesn't burn! Try it and you will see, at worst it burns out, turns black, but it doesn't take.


Non-flammable it is not supposed to be consumed ... in a house on fire, "confined" home, I would be surprised that there is a lot of PU foams left at the end ... and big toxic fumes ...

It may not be a flame spreader ok ... but not non-flammable! Besides, what is the flame on the bombs of your photo? (maybe this concerns the propellant?)

As I am skeptical and I have lots of PU scraps from my site, I will try to light one this week ... : Cheesy:
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by chatelot16 » 27/05/13, 00:57

yes we find everything in these forum ... it's all about finding where it is ... and that's why I find that following a forum is a wiki to rank better ... but that's another story

these reflections on the air knives gives me a big idea of ​​stingy: if I have to use expanded polystyrene, I already noticed that the price by volume was constant for all the thickness ... so no need to put 100mm of thickness in a block it is better to put a superimposition of 20mm, but not exactly overlapping: the plates are superimposed only on the edges, but on the majority of the surface it is an alternation of 20mm of air and 20mm of polystyrene : if this principle is good it divides the price almost by 2 for an equal result
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ITI / ITE by partitioned air cavity (non-ventilated air space)




by Obamot » 27/05/13, 01:12

The only problem with polystyrene is that houses are known to move over time! With foam, it will eventually make a small cavity, but it won't go any further.

Whereas in the case of panels that have moved, depending on how the seal will no longer be ensured (in the case of a combination with confined, or non-ventilated air spaces). Now I find the idea of ​​a combination interesting. It's to dig, maybe just a design story.

But in any case I would drop the expanded for the extruded, because it sticks to the polyurethane foam, it is less brittle and compresses more easily (so it's safer).

Christophe wrote:
Obamot wrote:Nada, niet, nothing ... it doesn't burn! Try it and you will see, at worst it burns out, turns black, but it doesn't take.


Non-flammable it is not supposed to be consumed ... in a house on fire, "confined" home, I would be surprised that there is a lot of PU foams left at the end ... and big toxic fumes ...

It may not be a flame spreader ok ... but not non-flammable! Besides, what is the flame on the bombs of your photo? (maybe this concerns the propellant?)

As I am skeptical and I have lots of PU scraps from my site, I will try to light one this week ... : Cheesy:

Okay, I bow. We already talked about gas, I confirm.

Christophe wrote:
chatelot16 wrote:I had looked for figures a long time ago, and I had found that (...)


And this one: https://www.econologie.com/forums/isoler-des ... t8971.html ?

In any case, I find that the idea has evolved since then. We finally have this thickness figure of 25mm maximum of confined air space (I was already not for 30 or 40mm at the time).
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