  Accretion disks with an additional mass input on the disk surface from
environment are considered in the limit of low mass input rate, i.e. when the
accretion flow remains keplerian. Due to dissipation of kinetic energy of the
infalling gas disk temperature increases, and can deviate significantly from
standard temperature of reprocessing accretion disks in their outer regions.
This increase in temperature produces an excess of emission in a
long-wavelength range of the disk spectrum. An illustrative example of the
spectrum of a weakly mass-loaded disk (the surface mass input rate Mdot_{load}
~= 1.5 times 10^{-8} Msun yr^{-1}) reasonably reproducing FIR excess observed
in CS Chameleon is given.
