The gases generated at electrolytic cells (or pots) of aluminum smeltersAluminum smelter are drawn into scrubbers to keep overall emissionsEmissions below regulation limits and to protect workers from being exposed to fumes generated by the pots. Whilst most smeltersSmelter have a constant flow being drafted from the pots, some plants include a “high draftHigh draft” ventilationVentilation mode which allows a boosted draft that enhances gas collection when maintenance is performed at the pots. This paper describes the versions for “high draftHigh draft” ventilationVentilation and explains the components and the effect on pot flows for the different designs.