  Within the environmental context, several tools based on simulations have
been proposed to analyze the physical phenomena of heat and mass transfer in
porous materials. However, it is still an open challenge to propose tools that
do not require to perform computations to catch the dominant processes. Thus,
this article proposes to explore advantages of using a dimensionless analysis
by scaling the governing equations of heat and mass transfer. Proposed
methodology introduces dimensionless numbers and their nonlinear distortions.
The relevant investigation enables to enhance the preponderant phenomena to
\emph{(i)} compare different categories of materials, \emph{(ii)} evaluate the
competition between heat and mass transfer for each material or \emph{(iii)}
describe the transfer in multi-layered wall configurations. It also permits to
define hygrothermal kinetic, geometric and dynamic similarities among different
physical materials. Equivalent systems can be characterized in the framework of
experimental or wall designs. Three cases are presented for similarity studies
in terms of \emph{(i)} equivalent material length, \emph{(ii)} time of heat and
mass transfer and \emph{(iii)} experimental configurations. All these
advantages are illustrated in the given article considering $49$ building
materials separated in $7$ categories.
