How do deep sea creatures breathe?

[IronWing]

But you sounded like the air was chiefly dry to prevent oxidation, and yet you quote the webpage saying because it's from hot bleed air. What position do you take?

I knew about the hot bleed air. But I also knew they recerculate the air. I added the word, "largely."

Re-circulation, w/o refrigeration, would make the air more moist, not more dry. The passengers exhale lots of water vapor and sweat a bit.