Insulation
This node is the default boundary condition for the Moisture Transport interface. This boundary condition means that there is no moisture flux across the boundary:
and hence specifies where the domain is insulated. Intuitively, this equation says that the relative humidity gradient across the boundary is zero. For this to be true, the relative humidity on one side of the boundary must equal the relative humidity on the other side. Because there is no relative humidity difference across the boundary, moisture cannot transfer across it.
Note that on the boundaries of Building Material features and Hygroscopic Porous Medium features with Equilibrium between liquid and gas phases set to Equilibrium formulation, the moisture flux contains both the vapor diffusive flux and the liquid capillary flux:
It can be applied on exterior boundaries only.
When this node is added as a subnode of a Liquid Water (Hygroscopic Porous Medium) or a Moist Air (Hygroscopic Porous Medium) node, it only constrains the liquid capillary flux or the vapor diffusive flux respectively.
Location in User Interface
Context Menus
Moisture Transport in Air > Insulation
Moisture Transport in Building Materials > Insulation
Equilibrium Moisture Transport in Porous Media > Insulation
Nonequilibrium Moisture Transport in Porous Media > Hygroscopic Porous Medium > Liquid Water > Insulation
Nonequilibrium Moisture Transport in Porous Media > Hygroscopic Porous Medium > Moist Air > Insulation
Ribbon
Physics tab with interface as Moisture Transport in Air, or any version of the Moisture Transport interface selected:
Boundaries > interface > Insulation
Physics tab with Hygroscopic Porous Medium > Liquid Water or Hygroscopic Porous Medium > Moist Air selected in the model tree:
Attributes > Insulation