Exact calculation of thermal insulation

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Remundo
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by Remundo » 25/01/16, 09:26

absolutely agree with your analysis.

however, the thermal resistance of glass wool is fairly well known.
The ISOVER range presents 3 main families of mineral wools, differentiated by their thermal resistance at equal thickness: λ = 0,032; 0,035 or 0,040, or R = 3,1; R = 2,85 and R = 2,5 in 100 mm thickness, as well as the Multimax R = 3 range in 90 mm.

Source Isover

Thermal resistance = thickness / lambda / surface
Watch out for the units as usual.
The reflective coefficient of a metal also, the radiative emission according to the temperature (tables of data exist in infrared thermography, to see the last page of my doc) etc ...

after that it's just a matter of calculation.
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by Obamot » 25/01/16, 11:59

chatelot16 wrote:but the vacuum seems to me unusable in building because it is necessary to resist the atmospheric pressure, so to put shims supporting the compression between the flat face, and the material of the wedge drives the heat

This is why in windows 2V or 3V we put a gas, for example argon, to create a pressure that fights the atmospheric pressure.

Willy should try? : Lol:
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by Christophe » 25/01/16, 12:53

Obamot wrote:If one of these 4, you could a little coach around this spreadsheet, it interests me to discover another method!

;-)


Here I have just recalculated the K of my cellar following the 2013 cellar isolation project: https://www.econologie.com/forums/calcul-du- ... tml#297949

It is good this small .xls, with same forecasts of consumption and breakdown (accounting) speaking post by post, this calculated on the DJU (the database only concerns Belgium, so it is more or less valid so for all the North, above Paris, France ... otherwise we can always edit the .xls by putting the exact DJU from your home)
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by Remundo » 25/01/16, 12:56

yes in the most expensive and insulating windows, we put these famous noble gases which have a lower thermal conductivity than the air.

I looked more closely at the thermal conductivities of glass wool.

The best quality comes to 0.030 W / m² / K,

it is impressive when you know that the air at 0,026 W / m² / k.

We can say that these glass wools are "expanded air".

In the same way, there are also concretes / cinder blocks full of air bubble, reputed to be insulating.

The advantage of glass wool is that it blocks convection, whereas within a too thick air space, there can be conducto-convective exchanges able to erase the advantages of very low conductive thermal resistance.

Glass wool is also easy to put everywhere.

The disadvantage is that it is opaque, so not possible in the window.
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by Remundo » 25/01/16, 12:57

Christophe wrote:It is good this small .xls, with same forecasts of consumption and breakdown (accounting) speaking post by post, this calculated on the DJU (the database only concerns Belgium, so it is more or less valid so for all the North, above Paris, France ... otherwise we can always edit the .xls by putting the exact DJU from your home)

It's a good file, but you have to take the time to enter all the parameters.

Capt'n Maloche was not in a BE Thermal building? He must have nice simulation software, right?
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by Christophe » 25/01/16, 13:05

Remundo wrote:It's a good file, but you have to take the time to enter all the parameters.


Yes!

The longest (I did it for my whole house, it took me 1 / 2 day just for the measurements), it's
a) understand the method
b) to measure the surfaces ... and to estimate the R of the walls ... (not obvious if we did not do the same site) + the possible thermal bridges ...

Remundo wrote:Capt'n Maloche was not in a BE Thermal building? He must have nice simulation software, right?


Yes certainly but not necessarily free like this ... then on the web of 2016 nothing good is really free (except the forums... and still some become paid on subscription!)

Another Belgian software was extremely complex (kind it had to enter: types of shutters, successive layers of each wall and make a plan in 3D scale home with orientation and location for solar contributions. .. among others !!).

Finally it is its complexity that limited its use (even for the ingested and archi!) But if we had all the data it was the TOP of the TOP!

Cherry on the cake: I wonder if he too was not free to use ... I will search my archives ...
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by chatelot16 » 25/01/16, 13:23

the simulation software does not answer my question because it only compute with the simplified data that I question

what I would like is the raw measurement data of 1m2 of glass wool at different temperatures

if the curve is linear with the temperature difference, it will confirm the precision of the calculations with constant lambda

if the curve is twisted it will be possible to deduce if there is a part of the heat transmitted other than by conduction ... I suspect that the convection is not strictly zero since the glass wool is not completely waterproof

if the convection is really negligible the efficiency will increase proportionally to the thickness ... if the convection is not negligible the thermal resistance will not increase proportionally to the thickness, and will be improved by sharing in several layer with waterproof film

this morning I saw on tv a commission to senate on the conflict of interest in health expertise: he complained that the experts did not have access to the raw data of the clinical trials, but only reports of tests too well cleaned

we are in the same case in isolation materials: the measurements are made but we only have simplified results

if nobody finds what I'm looking for, I just have to build a way of measuring
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by Christophe » 25/01/16, 13:28

chatelot16 wrote:the simulation software does not answer my question because it only compute with the simplified data that I question


When you see the one I just mentioned, you will no longer speak of "simplified data" believe me!

After that, nothing is better than the actual measurements!

Own revolutionary econological idea: does the method exist ????

Measurement on 1 at indoor and outdoor temperatures, precise energy consumption and op gives the real energy performance of the home!

In fact this would be a real K to compare to the estimated K in the spreadsheet above.

The main difficulty in this method would be to measure the interior temperatures precisely, because they obviously vary from one room and time to another!

It would therefore 1 long-term probe per piece and an external probe and do an integration on 1 year.

She is not good this idea ???? To dig!!
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by Christophe » 25/01/16, 14:05

Christophe wrote:When you see the one I just mentioned, you will no longer talk about "simplified data" believe me !!


Here I found it: it is the software PEB!

Here it is for free download: http://energie.wallonie.be/fr/telecharg ... IDD=113530

Windows, MAC and even Linux sivouplé well eh!
There are still some cool things in Belgium!

For the manuals it's here: http://energie.wallonie.be/fr/logiciel- ... l?IDC=7303

190 pages and 17 MB the manual :)

French version :

PDF Manual for PEB software as a whole (PDF-17216 KB)
PDF Handbook specifically dedicated to the 3D modeler (PDF-6496 ko)


There is a dedicated manual for modeling 3D ...

When I told you it was chiaded it's not for nothing! And again I have only tested a version of 2012 ... I guess it has become even more complex!

When you master chatelot I think you can not talk about approximation I think ...

Good fun zamis! : Cheesy:
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