@uhoh as requested, i've added a basic air circulation system to the atrium hab. The image is a bit dark but i hope it gets across how it works.

each tube is a meter in diameter. i'm just eyeballing it, it seems like enough but i don't know.

on the top, I would align with beams of the "roof", and they actually can have built-in stuff for that.

but yeah, good addition

I would get with floors and the roof as main flow creators - just some up to downflow and be done with that, expect places which really need dedicated ventilations

hm. those are good points

the roof beams have a bottom section that slides over in the event of a solar storm, so they can't accommodate an air circulation system

point was, the presence of a system not necessarily is so obvious, but it is the problem of conveying information in visual manner and actual implementation

yes, i have thought about that, now that you said it. i'm okay with this design though. i like industrial looks, when they are done well. Also i wonder about accessibility of systems recessed into walls and floors. It's extra excavation and could make achievement of a good, long-lasting seal for the atmosphere more difficult.

maybe not a factor far down walls excavated out of the ground. i'm not sure.

you do not need extra excavation. you have the main real wall, and a fake wall which anyone sees and a distance 1.5 meter between where different communications etc are

but generally, point is do not mind that too much. Added stuff to symbolise presence and that enough - people can recodnise and assume the utility, so that's fine

if it isn't actually recessed instead, i actually like the way this looks, more than putting in false walls and hiding it behind them. that only means you lose more space for the sake of an aesthetic. i'm more in favor of letting it show and making it nice.