The Moisture Transport in Air Interface solves for the following equation, in which the moisture content variation is expressed through the transport of vapor concentration,
cv, by convection and binary diffusion in air:
where ρg is the moist air density (SI unit: kg/m
3).
By neglecting the spatial and temporal variations of ρg in the equations above, the equation of the diluted species formulation,
Equation 4-135, is obtained.