Isolate vertical walls with an air gap and lathing?

[Christophe]

Before wasting your time, I advise you to read this.
http://www.cstc.be/homepage/download.cfm?dtype=publ&doc=CSTC_Rapport_9.pdf&lang=fr

Who will answer your questions numbers.
Including the performance of an air gap depends a lot on the emissivity of the surface trap that blade.
How is measured lambda of materials ...

Super doc, thanks again.

I have just finished the "theoretical" part (1st part before tests on thin layers) of which here is a summary:

- for a thin insulator to "work" you must have a non-ventilated air space (ideally 2), I think that a good number of dissatisfied people have not put these slats ... but be careful that does not mean that we arrive at 200 mm equivalent of insulating wool so far! Only we greatly improve performance (almost zero without this or these blades !!)

- a non-ventilated air space is a "sealed" space whose thickness is at least 10 times less than each of the other dimensions

- ideal vertical air space (the case that interests us for walls) = 20 mm thick (contradicts the graphic above)

- maximum dimension of an air space = 30 cm

In short, ideally, a "square" lathing 2 cm thick and 30 cm should be made. In the end, the lathing (quite a lot of time) and the price of thin insulation, even 1st price may exceed that of a classic insulation installed much more quickly!

I couldn't help but read the conclusion, here is the essential:

Due to its small thickness, a PMR has a low intrinsic thermal resistance, the measured values ​​varying from 0,2 to 0,6 m².K / W depending on the type of product. To be able to benefit from the reflective effect of the surface layers, the product must be placed opposite one or, better, two non-ventilated air spaces. Under these conditions, the emissivity value of the external faces of the product is an important parameter, which determines the reduction of the heat transfer by radiation through the air space. The measured emissivity values ​​range from 0,05 to 0,20.

The total measured thermal resistance of each associated product with two 20 mm thick non-ventilated air knives varies from 1,0 to 1,7 m².K / W depending on the type of product and the direction of the heat flow passing through it.

[elephant]

Christophe wrote:

A few days ago, you were nevertheless pro "reflector sheet" on this subject

Absolutely: when the reflective sheet is as close as possible to the heat source: behind the finishing gyproc plate, for example, or even behind the wallpaper.

The physiological effect reinforces theoretical thinking.

[bernardd]

Thank you, in addition I just understood the insulating power of snow, while water is a very good conductor of heat:

snow is water which traps air, and whose whiteness reflects light.

It would therefore be necessary to add a shiny layer in the gas bubbles of our conventional insulation :-)

Or put the carpets on the walls in fashion, which make a warm wall, with a second layer of thin shiny insulation behind, between the carpet and the wall!

it must also be the principle of recent ski anoraks, with their shiny layers. And in addition the new ones that we can inflate to create the air space ... We would therefore need thin inflatable insulators :-)

[elephant]

Absolutely, Bernard! Besides, some thick insulators (isover, for example) exist with an aluminum foil on the Kraft sheet! And since ???? thermos bottles have a reflective layer.

Interesting experience: put your hand in a sheet of household aluminum.

[quovadis]

What are the references of this technical doc:

- for a thin insulator to "work" you must have a non-ventilated air space (ideally 2),

and how to? The air mixes on its own, no.

- an unventilated air space is a "tight" space

waterproof?

- ideal vertical air space (the case that interests us for walls) = 20 mm thick (contradicts the graphic above)

the ideal air gap is when there is none. Pkoi keep it simple q we can do hiding

In short, ideally, a "square" lathing 2 cm thick and 30 cm should be made. In the end, the lathing (quite a lot of time) and the price of thin insulation, even 1st price may exceed that of a classic insulation installed much more quickly!

architect's speech? In college it would be worth a dotted zero not

[elephant]

In short, ideally, a "square" lathing 2 cm thick and 30 cm should be made. In the end, the lathing (quite a lot of time) and the price of thin insulation, even 1st price may exceed that of a classic insulation installed much more quickly!

Yep, wood is expensive, screws and dowels too and it's tedious to do. In the extreme, if the surface allows it, some insulations stick.

[quovadis]

battening, dear? Don't overdo it, after the air is free

[Christophe]

battening, dear? Don't overdo it, after the air is free

Already you will calm down with your "tone", stop asking stupid questions ...

So you're going to read the .pdf in question stp before opening it (but are you maybe too lazy to click on it? Or much smarter than CTSC experts? )

Yes a batten batten in 30 x 30 cm is expensive per m² especially in time or labor if you have it done (because everyone does not know or does not want to tinker ...) in all cases it is much more expensive than a laying of thick insulation (where it there is almost nothing to do) so the advantage of thin insulation is certainly not economical!

This price is even higher if you want a "double" air gap and therefore double lathing ... which is mandatory if you want a "minimum" of performance ...

As a minimum handyman I will test ... the simple blade to start ...

[quovadis]

confusion. It all depends on what is called "air gap". An air space cannot be an enclosed space, by definition, right? Otherwise it becomes a pocket of air trapped between two films (well that's how I understood the trick). But that's just my opinion and frankly it didn't really make you want to read the link.

[Alain G]

confusion. It all depends on what is called "air gap". An air space cannot be an enclosed space, by definition, right? Otherwise it becomes a pocket of air trapped between two films (well that's how I understood the trick). But that's just my opinion and frankly it didn't really make you want to read the link.

The air knife has been used here in Canada for at least 30 years, it is undeniable that it improves the insulation.

You should read this document instead of arguing!

No hard feelings!