My point is at some point I think it's reasonable for the author to follow the rule of cool and let it be that. Any author drilling down to the minutiae of everything could well make his work his life ( and unfortunately ours as well ) and nothing else. Better works will have some poor math ( i.e. errant detail not adding up ) in that the author is mindful of the reader, not dragging him/her along to explain every spec of dust in the room. All of Bakker's detail in my opinion is simply a near perfect balance with rich scenery and movement in the story. Don't reggae with this balance by trying to drag him down into the mud of ensuring EVERYTHING makes sense ( not that he would be so weak to submit, but just saying ).
To contradict myself, it is fun to point these things out - nice catch in this case - but not as criticism, but simply to drive interesting conversation and learning - it did not occur to me underground dwellings require ventilation, but seems obvious now that it's brought up. It does seem that the posts here are mere that - something cool to talk about - which is good. To throw in, could be non-men have tolerance for higher CO2 levels and their human slaves adapted over time. Could be air conditioning technology they received from the aliens ( think I recall impressive amounts of machinery laying about in the mansions, but could be a made up memory on my part ).