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If you want to live in an air tight containers, you need to also be concerned about co2 buildup.
by danielvf 11y ago
If you want to live in an air tight containers, you need to also be concerned about co2 buildup.
- jryan49 11y agoWouldn't the co2 buildup kill you first anyway?
- z92 11y agoCO2 buildup will kill him far before all the O2 has been used up. Even supplying fresh O2 into the room from a cylinder won't save him, unless someone finds a way to remove CO2 from the room.
- sjwright 11y agoIt's useful to remember the makeup of air: 78.1% nitrogen 20.9% oxygen 0.93% argon 0.039% carbon dioxide Carbon dioxide, in very approximate figures, is unpleasant at 0.5%, dangerous at 5%, fatal at 10%.
- Dylan16807 11y agoYou're going to be doing pretty badly with half the oxygen gone even if you had no CO2.
- oh_sigh 11y agoWhat about venting some of the rooms air to space, and then releasing some O2 into it?
- madaxe_again 11y agoCame to say precisely this. Before you run out of o2 the co2 levels will likely render you unconscious, and will potentially also suppress your breathing. I took a lungful (choked on the first breath, coughed, started really choking) of air heavy with co2 in a pub cellar once. Only because I fainted on top of the kegs above the co2 saturated air on the floor (leaky cylinder valve) am I here to tell you about it. Tastes like acidic metal and black velvet rushes in.
- masklinn 11y agoAn other fun danger of insufficiently aerated rooms: in wine countries, until cellars aeration became more widespread a huge danger was CO buildup in cellars from fermentation, to these days people regularly die during initial fermentation, and a warning you get is "if you see somebody unconscious at the bottom of the cellar stairs you do not go down to help, you call the firefighters, trying to help just ensures they have two bodies to retrieve".
- justinclift 11y agoSo, horror movies are realistic for once. If you see your friend lying dead in the cellar... GTFO of there, it really is zombies (or gas buildup of some variety) . :)
- adevine 11y agoThere are, sadly, lots of reports of farmers and their family members dying in manure pits due to a buildup of CO2 and methane. Someone goes in first and passes out, and then anyone else who tries to go in to save him suffers the same fate. In one case 5 members of a dairy farming family all died trying to save their father.
- mrfusion 11y agoWhat if you hold your breath to help?
- Amezarak 11y agoI've always been confused by this too - you'd think holding your breath would make it safe-ish. I can only assume that it's still extremely risky because even if you remember to do it, you are very likely to misjudge how long you can hold your breath during an emergency situation with adrenaline pumping that requires you to drag someone up the stairs. Which means you get halfway up, end up forced to take a big deep breath, and pass out.
- g8gggu89 11y ago
- johnernaut 11y agoThis can be alleviated with the use of CO2 scrubbers[0]. Basically you fill fan-powered canisters with minerals ("sodasorb" is a popular product used in the offshore diving industry), which absorbs CO2 from the atmosphere. That's not to say that you need to be able to remove and replace the minerals in the scrubbers every so often. [0] https://en.wikipedia.org/wiki/Carbon_dioxide_scrubber https://en.wikipedia.org/wiki/Carbon_dioxide_scrubber
- junke 11y agoOut of curiosity, do you have an idea of the typical delay before saturating the filter? Do you have some pointer to space suits specification or something like this that I could read to have more information?
- msl 11y agoAccording to Wikipedia, "One gram of anhydrous lithium hydroxide can remove 450cm³ of carbon dioxide gas."[1] Also according to Wikipedia, a person produces some 1kg of the gas a day [2], which translates to roughly 550000cm³. That means around 1.2kg of lithium hydroxide per day per person. The Apollo 13 LM canisters were rated for some 56 hours for two persons, but could only support three for less than 35 hours. That seems to fall somewhere between 5 and 6 kilograms, and apparently includes the scrubbers of the space suits onboard. Each suit was designed to support life for 6 hours (+ 30 minutes of emergency reserves) [3] which means some 350 grams of lithium hydroxide. The longest EVA thus far lasted for just under 9 hours [4], for which you would need a bit more than 450 grams of lithium hydroxide. The Russian Orlan suits are designed to support life for between 5 and 7 hours [5]. An astronaut on an EVA might produce more carbon dioxide than the Wikipedia approximation, so you might want to round those numbers up. Edit: I am also not sure how close to the theoretical maximum that absorption capacity is, so the numbers might really be somewhat optimistic. [1] https://en.wikipedia.org/wiki/Lithium_hydroxide https://en.wikipedia.org/wiki/Lithium_hydroxide [2] https://en.wikipedia.org/wiki/Carbon_dioxide#Human_physiology https://en.wikipedia.org/wiki/Carbon_dioxide#Human_physiolog... [3] https://en.wikipedia.org/wiki/Apollo/Skylab_A7L https://en.wikipedia.org/wiki/Apollo/Skylab_A7L [4] https://en.wikipedia.org/wiki/Extravehicular_activity https://en.wikipedia.org/wiki/Extravehicular_activity [5] https://en.wikipedia.org/wiki/Orlan_space_suit https://en.wikipedia.org/wiki/Orlan_space_suit
- tblomseth 11y agoArguably, that was THE critical issue for crew survival after the Apollo 13 incident leading to the famous 'jury-rigged' CO2 scrubbing device improvised by the engineers on the ground 'Availability of lithium hydroxide (LiOH) for removing carbon dioxide presented a serious problem.'[1] [1] https://en.wikipedia.org/wiki/Apollo_13#Crew_survival_and_return_journey https://en.wikipedia.org/wiki/Apollo_13#Crew_survival_and_re...
- yathern 11y agoOn an unrelated note - I read your term 'jury-rigged' and was thouroughly confused for a good minute. It sounded right in my head, but reading it on paper (screen) it looked wrong. Except looking up 'jury rigged' led to results about... Juries being rigged. Eventually I realized that the term I was looking for is 'Jerry Rigged': http://www.merriam-webster.com/dictionary/jerry%E2%80%93rigged http://www.merriam-webster.com/dictionary/jerry%E2%80%93rigg... Which is 'probably a blend of jerry-built and jury-rigged', so now I don't know what to believe.
- codezero 11y agoThat's odd, the first two results for me when I search for jury rigged is a Google summary box with the definition and the Wikipedia article: https://en.wikipedia.org/wiki/Jury_rigging https://en.wikipedia.org/wiki/Jury_rigging Are you studying law or something, maybe Google is overly personalizing? :)
- dghughes 11y agoI got my parents a NetAtmo device it has an outside thermometer but also one for inside that also has a CO2 detector. It's amazing how often just my two parents plus one cat in a 5mx5m living room will cause it to reach near 1000ppm. At Christmas time with about eight people it easily hit 1000ppm very quickly. Nobody else knew but I was watching the readings and it was interesting to see how that point it seems stuffy so a window was opened for some fresh air. This is a 1970s single floor bungalow with forced air heating but no air exchange.
- lordnacho 11y agoI had a theory this was what caused me to feel really sleepy when attending lectures. Wasn't sure how to prove it, though of course it could make sense with the right figures plugged in.
- mrfusion 11y agoWould anyone be able to update his numbers accounting for co2 buildup? Are you thinking it would be a lot less time than he calculates?