When the ship is closed down, air in the citadel is augmented by fresh supplies drawn into the ship through air filtration units and re-circulated in the citadel.
Xa inqanawe ivaliwe umeya ekhusini wengezwa ngomeya ehlaziyekileyo esezelwa enqaraweni nge uniti ezingenise umeya uphinde ujikeleze ekhusini.