The Equilibrium Moisture Transport in Porous Media (mt) interface () is used to model moisture transport into the pores of a porous medium, through convection and diffusion of vapor in moist air, and convection and capillary flow of liquid water. A Hygroscopic Porous Medium model is active by default on all domains, with Equilibrium between liquid and gas phases set to Equilibrium formulation.

The water conservation equation defined in porous media domains corresponds to the convection-diffusion equation for the total moisture content. This equation is valid when vapor phase and liquid phase are in equilibrium. The relation between the relative humidity and the moisture content is described by the sorption isotherm curve. If not, use The Nonequilibrium Moisture Transport in Porous Media Interface instead.

When this physics interface is added, these default nodes are added to the Model Builder: Hygroscopic Porous Medium, Insulation (the default boundary condition), and Initial Values. Then, from the Physics toolbar, add other nodes that implement, for example, boundary conditions. You can also right-click Equilibrium Moisture Transport in Porous Media to select physics features from the context menu.

By default, the shape functions used for the relative humidity in porous media are Linear.