While working on a project, I realized that the definition of the P_Set „Thermal Transmittance“ does not comply with modeling regulations and restricts the model for flexibility. Since this value works only for all layers of an element (Outside – Inside or Up-Down), the model should have only multi layered components that work as one. The reality is off course different, where the model is built out of many single layered components that form the whole.
Therefore defining the U-Value for a single component does not make any sense. More reasonable is the conductivity of a single layer, which then combined in specific areas results in a U-Value.
May I ask why is this value anyway necessary? For permission planing (when delivered in IFC) it will still be not possible to identify which walls or slabs have a U-Value since they are modeled from at least two components. For Asset-Management in the future the conductivity of a certain material makes more sense if something has to be ordered/repaired. It is a value for/from the building physicist which considers it for energy performance simulations. When such a simulation is ready, the building physicists communicates to the planing team which materials should be adopted to fulfill regulations.
Can please anyone explain me the validity of this P_Set