Thermal bridges in roller shutter boxes?

[Christophe]

It is often advisable to install shutters to increase the thermal resistance of a chassis. We did it ... but I'm starting to ask questions.

Indeed; on the one hand this operation increases only slightly the thermal resistance of the chassis (0.2 to 0.3) on a chassis having a resistance without flap from 0.6 to 0.7. And it is obviously only valid when the shutter is lowered ...

But on the other hand, the box itself is rarely well insulated (when it is) and has, over time, many sources of leaks (especially wooden boxes).

So I start to wonder if the installation of shutters is not a more bad than a good thermally ...

This remark is more valid in renovation than nine, because in this case, we can well integrate the box in the wall with the insulation that goes well ... finally in theory ...

Case study with us: we have installed indoor wall, 2 years ago, a bay window Kömmerling pvc with integrated roller shutter. Glazing U = 1.1 (R = 0.9), chassis in U = 1.3 (R = 0.77), shutter alu insulated is about what is done better thermally in double glazing!

However our box has less than 1 cm of polystyrene insulation (R = 0.2 max!), On the other side, it is the "outside" thermally! As it is an interior wall installation, the box makes roughly 15-20% of the "interior-exterior" heat transfer surface of the frame.

In this configuration, I think we lose more calories than we save even closed shutter all the time ... I will measure temperatures this winter and try to make a thermal balance.

In short, it's not great and I still have to make a "double box" to put on the box. It must be removable to allow possible maintenance of the shutter ...

If some of you could check the insulation of their ca box would see if it is a unique case or if it is generalized ...

ps: this remark would not be valid with casings installed externally but most of this type of installation are rather ugly ... so we did not want to do so not to disfigure the facade ...

[bernardd]

Not only does this type of box bring cold air into contact with the heated room, but it also brings in the noise.

In an apartment in Paris, I had isolated windows against noise: no results.

Until I realized that everything was going through the uninsulated box. Once isolated, the difference was enormous.

[Christophe]

Ah yes the noise too ... I had not thought about it.

Did you isolate it how your box?

[bernardd]

I had found a coating resembling the trim under the car hoods, a kind of very heavy compressed fabric, because it's the mass that makes the sound insulation. About 10 to 15mm thick and quite rigid, to stick. But I just blocked it without glue.

The effect was magical, on a facade overlooking the belt boulevard in Paris: especially for the vibrations of large diesel!

No "professional" interviewed was able to make the diagnosis or give this advice, however simple.

[Christophe]

Thank you. Oh yes, I see the materials completely. A kind of braided synthetic wool.

No "professional" interviewed was able to make the diagnosis or give this advice, however simple.

Fortunately, since then there have been forums

[dedeleco]

"No teacher", that amazes me, because, it is well known in physics, that the waves are stopped by very large variations of index, and therefore for the sound, large variations of speed, and of index, of alternating layers of heavy, light, (cork, lead, air, lead, repeated, therefore finely divided between air and heavy particles !!
It's not that the heavy is the alternation of heavy, light!
In optics it's the same!
In building and insulation, the basics are not assimilated, and there are too many inconsistencies !!

The caissons are difficult to isolate, because the shutter must pass to wind and so the air and sounds circulate well too, with insulating layers laid ridiculous and the rubbing insulation on the shutter is a source of breakdowns and jams! !

But as long as the customers do not realize it, nothing is done, because the price increases !!

[bernardd]

I wrote "professional", not "teacher" :-)

They all wanted me to change the double glazing windows, but none thought that the noise came from the box ...

In fact, it was by wanting to clean the greasy black grime (the clean air of Paris ...) which was deposited around the axis of winding that I understood, I dismounted the wall of the box, which was a 6mm plywood: a perfect sound box!

[Christophe]

I wrote "professional", not "teacher" :-)

+1

He has probably forgotten, as it often happens, to change the glass of his glasses ...

[dedeleco]

Yes, I have not yet put double glazing on my glasses!

[dodo]

I ask myself the same question, in fact I wonder if my draft does not come boxes that are not isolated.