Dust SED for G₀ = 0.1, in the region (R [kpc], z [kpc]) = (22, 3.5) in the galaxy NGC 891. The red and blue lines represent the SED due to photon heating only, with (blue line) and without (red line) the size limitation at a_min = 2 nm. The green line represents the SED due to both photon and collisional heating with the size limitation at a_min = 2 nm (we assume the totality of the dust as embedded in the hot gas). Black lines represent the various contribution to the SED shown by the red line. We assume the same column density and gas properties as in Fig. 11.