Dust close (∼few pc) to the accretion disk in active galactic nuclei (AGN) is key to understand many of their observational signatures and it is key to trace how the AGN is fed or even evolve along its duty cycle. With estimated sizes of less than 10 pc, as constrained by mid-infrared high angular resolution data, only the superb spatial resolution achieved by ALMA is able to actually image this dusty structure. However, the question regarding the conditions in which the dust at sub-milimeter (sub-mm) wavelengths where ALMA operates, arises. We study the detectability of the emission associated with the AGN dusty structure at sub-mm wavelengths using ALMA, in a theoretical and observational way. Theoretically, we use the Clumpy models from Nenkova et al. together with the mid-infrared to X-ray and the radio fundamental plane scaling relations. We find that it is more likely to detect bigger and denser dusty tori at the highest ALMA frequency (666 GHz/450 µm). We also find that with 1h at 353 GHz/850 µm and 10h at 666 GHz/450 µm we can detect, with a high detection limit, a 1 mJy torus (characteristic of bright AGN). This means, an object for which the unresolved SED at 12 µm has a flux ∼ 1 mJy. Observationally, we use four prototypical AGN: NGC 1052 (low-luminosity AGN), NGC 1068 (Type-2), NGC 3516 (Type 1.5), and IZw1 (QSO), with radio, sub-millimeter, and mid-IR data available. All the mid-infrared spectra are best fit with the smooth model reported by Fritz et al. A power law and a single, or a composition of, synchrotron component/s reproduce the cm radio wavelengths. We combined and extrapolated both fits to compare the extrapolation of both torus and jet contributors at sub-mm wavelengths with data at these wavelengths. Our observational results are consistent with our theoretical results. The most promising candidate to detect the torus is the QSO IZw1 (therefore, highly accreting sources in general), although it cannot be resolved due to the distance of this source. We suggest that to explore the detection of a torus at sub-mm wavelengths, it is necessary to perform an SED analysis including radio data, with particular attention to the angular resolution.