  The origin of gas falling from the halo toward the disk of the Milky Way is
still largely unclear. Here the amount of gas shed by the (older) halo red
giants is estimated. The distribution of red giants (RGs) in the halo is not
known but that of a subset of stars in the post RG phase, the sdB stars of the
horizontal-branch (HB), is. Using the mid-plane density and $z$-distribution of
sdB stars, the ratio of sdB stars to all HB stars, and the RG mass loss, the
infall due to total mass lost by all halo RG stars at $z>1$ kpc is calculated.
For the extended halo component $\dot{M}_{\rm halo RGs} \simeq 1.4 \cdot
10^{-5}$ \msun kpc$^{-2}$ yr$^{-1}$ while the thick disk component RGs
contribute $\dot{M}_{\rm thick disk RGs} \simeq 5.4 \cdot 10^{-5}$ \msun
kpc$^{-2}$ yr$^{-1}$, each with an uncertainty of a factor 4. The total rate of
infall due to RG mass-loss is $\dot{M}_{{\rm RGs at\}z>1 {\rm kpc}} \simeq 7
\cdot 10^{-5}$ \msun kpc$^{-2}$ yr$^{-1}$, a sizeable fraction of the equally
uncertain observed rate of infall of material. Since most of the RG stars in
the extended halo are old, their mass loss is predominantly metal-poor, while
that of the disk RGs is more metal-rich. The galactic fountain flow provides
additional metal-rich infall and small galaxies being accreted contribute to
the infall of gas as well.
