Oh, you mean things like life support and supplies? Acumen transports all that in, from what I can tell. For air, I imagine it's is either converted from the water outside, or circulated through re-breathers in the ventilation units, or even pumped down from the atmosphere far above -- but that seems like a lot of energy since it's supposedly so high above us. [ No clue she might be going over anyone's head with all this. ]