recordGeneric

Thermal properties of opaque constructions
Diagram of GenericOpen the diagram

Information

Generic record with material definitions for constructions with one or more layers of material. By convention, layer[1] is facing the outside, and the last layer is facing the room-side. This is the same convention as is used in EnergyPlus and in Window 6.

The parameters absIR_a and absIR_b are used to compute infrared heat radiation (in the infrared spectrum). The parameters absSol_a and absSol_b are used to compute solar heat radiation (in the solar spectrum).

The parameter roughness_a is used if the convective heat transfer coefficient of the exterior surface is computed based on the wind-speed, wind-direction and temperature difference. See Buildings.HeatTransfer.Convection.Exterior.

Parameters

TypeNameDefaultDescription
IntegernLayNumber of layers
Buildings.HeatTransfer.Data.BaseClasses.Material[nLay]materialLayer by layer declaration of material, starting from outside to room-side
RealRsum(material[i].R for i in 1:nLay)Thermal resistance per unit area
Modelica.Units.SI.EmissivityabsIR_a0.9Infrared absorptivity of surface a (usually outside-facing surface)
Modelica.Units.SI.EmissivityabsIR_b0.9Infrared absorptivity of surface b (usually room-facing surface)
Modelica.Units.SI.EmissivityabsSol_a0.5Solar absorptivity of surface a (usually outside-facing surface)
Modelica.Units.SI.EmissivityabsSol_b0.5Solar absorptivity of surface b (usually room-facing surface)
Buildings.HeatTransfer.Types.SurfaceRoughnessroughness_aBuildings.HeatTransfer.Types.SurfaceRoughness.MediumExterior surface roughness
Advanced
Integer[nLay]nSta{material[i].nSta for i in 1:nLay}Number of states in each layer

Revisions

  • September 10, 2018, by Michael Wetter:
    Declared nSta to be final as the user is not supposed to change its value.
  • January 05, 2017, by Thierry S. Nouidui:
    Added parameter nSta to avoid translation error in Dymola 2107. This is a work-around for a bug in Dymola which will be addressed in future releases.
  • July 1, 2013, by Michael Wetter:
    Changed the annotation of the instance material from Evaluate=true to Evaluate=false. This is required to allow changing the material properties after compilation. Note, however, that the number of state variables in Buildings.HeatTransfer.Data.BaseClasses.Material are only computed when the model is translated, because the number of state variables is fixed at compilation time.
  • March 13, 2013, by Michael Wetter:
    Replaced Buildings.HeatTransfer.Data.Solids.Generic with Buildings.HeatTransfer.Data.OpaqueConstructions.Generic to allow use of phase change material.
  • November 16, 2010, by Michael Wetter:
    First implementation.