Calculation of the actual thermal resistance of a placed insulator

[Christophe]

I launch this topic to think about a method of determination of the real thermal resistance (thus lambda) of an insulator in place.

Goals: check the manufacturer's data, see the outfit in time, check if your insulator is still as effective ... etc etc

So to make it simple: Does anyone know of an "accessible" method, ie without laboratory resources or specialized devices (with a meter and a thermometer for example) to estimate the real resistance of an insulation in place.

I will cogitate! Normally with heat transfer equations it should be possible ...

[Christophe]

Well, I think it's not that easy.

I think you must have the power dissipated through the insulation because:

P = S * C / R

With S = Surface of the insulation (we have)
C = Delta of T ° insulator (one has)
R = Thermal resistance (we are looking for)
P = Power that passes through (we try to measure)

So maybe there is a possible method indirectly, like putting an electric heater in the room "fully" whose power we know and then doing a differential calculation without the heater?

Opinions?

[Capt_Maloche]

Here is what I do to determine the surface temperatures according to the materials of a wall



The only way to check the quality of an insulation will be to measure with great accuracy the internal and external surface temperatures using an infrared thermometer for example

which makes it possible to determine the resistance of the walls

[Capt_Maloche]

T'ain, we see nothing with the reduction of images!

Pffu

[Christophe]

Do you "lend" me the file I'm looking at? Say yes say yes

Are you sure it meets the demand?

[Capt_Maloche]

Just do the inverse calculation to obtain the thermal resistance of a wall

Send me an e-mail at the office tomorrow, it's made in Maloche, I'll send it to you

[Christophe]

Well received the file, thank you. It's interesting.

But I do not have the impression that the inverse computation works so easily that ... because to determine the different T ° you use the partial R AND the total R (sum of the partial R) ...

So in the extreme: partial R = total R.

It should be possible to obtain the R with only the internal and external wall T ° and the thickness of the wall. But this is not the case if ???

Take the case above:

- delta = 26.36 ° C.
- thickness = 0.54 m (the cow is bunker?)
- global R = ????

I'm drying there or else something escapes me ...