Moisture Flux

Use this node to add moisture flux across exterior boundaries, with the option to account for latent heat source due to evaporation. A positive moisture flux adds moisture to the domain.

Moisture Flux

Select the from the list: (the default), , or .

General Moisture Flux

It adds g0 to the total flux across the selected boundaries. Enter a positive value for g0 to represent a moisture flux that enters the domain.

Convective Moisture Flux, Concentrations Difference

Several options are available to specify the hm.

•

The default option is to enter a value for hm.

•

With the option, the heat transfer coefficient h to be multiplied by the analogy factor to obtain the moisture transfer coefficient hm should be specified. It can be (in this case the , pA, the , Text, and the ,

should be specified) or selected from a list of heat transfer coefficients defined in Heat Flux features applied on the same boundary (in this case the external conditions defined in the corresponding feature are used).

•

For the , , , and options, the geometry and velocity parameters used in the correlation are the same as for the Heat Flux feature. Then the external conditions should be specified. First, set the , pA. For , enter a value or expression. Else, select an defined in an node under . In addition, enter an , Text. For , enter a value or expression. Else, select an defined in an node under . Finally, set the ,

. Note that the relative humidity at the boundary is provided by the physics interface.

For all options except , select the check box to set the variable n in Equation 4-195.

Convective Moisture Flux, Pressures Difference

Enter a value for the βp. In addition, two options are available to specify the external conditions:

•

If is selected (the default), set the ,

and the , Text (used for the computation of the vapor saturation pressure). For , enter values or expressions. Else, select an and an defined in an node under . Convective moisture flux is defined by g0 = βp(

psat(Text) −

psat(T)).

•

If is selected, enter an , pv,ext. Convective moisture flux is defined by g0 = βp(pv,ext −

psat(T)).

Evaporation

Select the check box to define the moisture flux as an evaporation flux, and to contribute to the total latent heat source mt.q_evaptot.


	Condensation Risk in a Wood-Frame Wall: Application Library path Heat_Transfer_Module/Buildings_and_Constructions/wood_frame_wall

Location in User Interface

Context Menus

Ribbon

Physics Tab with interface as , , or selected: