Efficiency and accuracy of different potentials for the simulation of moisture transfer in building materials

Much disparity exists on the numerical efficiency and accuracy of different potentials for moisture transfer in building materials, with various implicit claims but no actual corroboration. This paper aims at providing such evidence by comparing the numerical efficiency and accuracy of capillary pressure, relative humidity and -log(-capillary pressure) for a suite of benchmark simulations.  The study shows that capillary pressure and relative humidity outperform -log(-capillary pres-sure), as the latter is plagued by its highly non-linear moisture capacity near saturation.  Capillary pressure and relative humidity are thus the potentials of choice.