Very ballpark-ish, a person can survive about a day for each 10 cubic meters of bolthole space. Increased carbon dioxide levels is what'll kill them, well before lowered oxygen levels. So yes, scrubbers are needed; the usual ones use sodium hydroxide or lithium hydroxide. They produce water (though I wouldn't drink it) and heat; so the bolthole gets kinda humid.
I could dig up the various published MP diagrams for bolt holes, but for my campaign a typical Recon team bolt hole is about 300 cubic meters. With a five-person team: 300 / 5 = 60 cubic meters per person; 60 / 10 = 6 days. A few simple chemical scrubbers could probably extend that; but I think oxygen tanks would be needed for a 28 day stay.
--
Michael B.
|