  The capillary condensation for fluids into spherical nano-cavities is
analyzed within the frame of two theoretical approaches. One description is
based on a widely used simplified version of the droplet model formulated for
studying atomic nuclei. The other, is a more elaborated calculation performed
by applying a density functional theory. The agreement between both models is
examined and it is shown that a small correction to the simple fluid model
improves the predictions. A connection to results previously obtained for
planar slits and cylindrical pores is done.
