HAMT Model Questions

asked 2019-06-26 05:17:36 -0600

ES Meyer gravatar image

I wish to model an example which was recorded in "Künzel, H. M. (1995). Simultaneous heat and moisture transport in building components : one- and two-dimensional calculation using simple parameters. Stuttgart: Fraunhofer IRB Verlag." (Example 1 on page 46). Regarding the model, I wish to know it it would be possible to model a single wall, as shown in the example, in EnergyPlus. Furthermore, is there a way in which the weather file can be ignore and direct loads can be applied, e.g. expected rainfall at the exterior surface.

Furthermore, regarding the HAMT model, I have the following questions:

  1. Does the HAMT only have input for absorption isotherm (MaterialProperty:HeatAndMoistureTransfer:SorptionIsotherm)?

  2. Is there an additional document which defines the variables used for the model (e.g. line 164 in the HeatBalanceHAMTManager.cc module does not define the watertot variable, but line 171 defines extvtc as the External Surface vapor transfer coefficient)

  3. Why is the input limited for to 25 interpolation points for the following properties:

    • MaterialProperty:HeatAndMoistureTransfer:SorptionIsotherm
    • MaterialProperty:HeatAndMoistureTransfer:Suction
    • MaterialProperty:HeatAndMoistureTransfer:Redistribution
    • MaterialProperty:HeatAndMoistureTransfer:Diffusion
    • MaterialProperty:HeatAndMoistureTransfer:ThermalConductivity
  4. Does EnergyPlus account for moisture transport below freezing point?

  5. Is the Gauss-Seidel iteration technique only used for the temperature calculation or for the relative humidity as well? Furthermore, a temperature threshold of 0.002°C is specified although the limit is 0.001°C in the model proposed by Künzel, H. M.. Is there a reason for the increase in convergence limit? Also, a relative humidity convergence limit is specified in the model by Künzel, H. M.. In the Engineering Reference Manual of EnergyPlus, no limit is specified. Is this convergence limit simply omitted from the document or is this convergence limit omitted from the HAMT model used in EnergyPlus?

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