ISO standard for non continous thermal bridge elements

[char...@salienteng.com]

I am trying to understand how ISO standards handle modelling of non continuous thermal bridge elements.  I am familiar with the North American standards, but am working with a European supplier and need to try to validate the information they are providing to me.

I am happy to purchase the standard that contains the methodology to be used, but I want to be sure I'm buying the correct standard.  Is this methodology defined in ISO 10077-2  Thermal performance of windows, doors and shutters — Calculation of thermal transmittance — Part 2: Numerical method for frames?

I see there is also a standard ISO 10211:2017  Thermal bridges in building construction — Heat flows and surface temperatures — Detailed calculations.  Would it be in that standard?  Or another?

[yal...@gmail.com]

Hi.

Which North American standard for calculating thermal bridges are you referring to? Would be good to know for better understanding of what you are looking for in the Euro standards.

In addition, could you provide a bit more detail what you are trying to validate or review? Is it a window, cladding clip, etc? ISO10077 is the method on calculating the u-factors for fenestration. ISO 10211 is for linear and point thermal bridges of exterior wall assemblies which windows are part of. So are different in their content.

Yalin

[char...@salienteng.com]

Yalin, thank you for your response.

I am looking at the u-factor of a window framing system that has a cross sectional profile that is not consistent along it's length.  It is similar to a "skip and debridge" profile, where there is a repeating pattern of a thermal breaks in the profile but the break is not continuous along the profile length, the thermally broken areas alternate with non-broken areas.  Similar to a pour-and-debridge thermal break that is not fully debridged.

According to the NFRC 100 procedure an effective thermal conductivity is established that takes into account the ratio of debridged and non-debridged areas.

The frame manufacturer (European) has provided me with a thermal conductivity value for the partially debridged area, but the value they have provided is much much lower than you would get if you used the NFRC 100 procedure.  I am trying to understand how they might have come up with the figure they are providing.