[EnergyPlus_Support] RE: Modeling of Thermal Bridges ?

[<fpasserini.tn@xxxxxxxxx>]

In DesignBuilder I create small subsurfaces in correspondence of the thermal bridges. The subsurfaces have a higher thermal transmittance than the normal surfaces. I calculate the modified thermal transmittance in order to have the correct heat flow in stationary conditions.

heat flow considering the thermal bridge = heat flow considering the subsurface

psi * h + UA = U1 * A1 + U * (A-A1)

where psi is the thermal bridge coefficient, h is the length of the thermal bridge, U is the thermal transmittance of the wall in "normal" conditions, A is the total area of the wall, U1 is the thermal transmittance of the subsurface and A1 its area

I suggest the article of Martin et al. "Problems in the calculation of thermal bridges in dynamic conditions": http://www.sciencedirect.com/science/article/pii/S0378778810003701

Best Regards

---In energyplus_support@xxxxxxxxxxxxxxx, <zupfera@...> wrote:

Hi all,

when entering the construction of the external walls the

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