It avoids movement through the corridors, lifts or elevators and clean zones. The smells disappear (created by the accumulation of dirty laundry or waste in the plants). Minimum manipulation.
A discharging installation of gravity has included mailboxes or loading chutes on each floor, by the ones the bags are introduced. This ones are displaced vertically through a metallic conductor, from the different points of the building plants until the discharging zone situated in the inferior plant.