[HN Gopher] Oxygen Candles: Providing Emergency Air
___________________________________________________________________
Oxygen Candles: Providing Emergency Air
Author : thunderbong
Score : 302 points
Date : 2022-05-10 04:39 UTC (18 hours ago)
(HTM) web link (minearc.com)
(TXT) w3m dump (minearc.com)
| wooptoo wrote:
| I believe these are the same candles used on submarines to make
| oxygen: https://www.youtube.com/watch?v=g3Ud6mHdhlQ
| perbu wrote:
| Hollywood has always perpetuated the myth that when you are in an
| air tight room you'll die as you run out of oxygen. The CO2
| poisoning will kill you before you run out of oxygen.
|
| So, if you're sitting in a nuclear shelter, remember to get the
| CO2 scrubbers working first, then worry about the low oxygen.
| kolinko wrote:
| Huh? How is Hollywood at fault?
|
| I think the myth is older than Hollywood and it is ingrained in
| our languages - when people begin to suffocate they say ,,I
| meed more air", not ,,The air is to stuffy". And this leads to
| a mental model of bringing more oxygen in as helpful instead of
| letting co2 helpful.
| jbay808 wrote:
| Hollywood at least got it right in _Apollo 13_!
| Hilbert1114 wrote:
| Hilbert1114 wrote:
| connordoner wrote:
| If memory serves, the incorrect storage of oxygen candles on
| Valujet Flight 592 was the cause of its crash.
| EdwardDiego wrote:
| Older Admiral Cloudberg write-up on that crash:
|
| https://imgur.com/a/vodAg
| kappuchino wrote:
| Good memory! Well, kind of ... here is the NTSB Report on the
| crash (PDF):
| https://www.ntsb.gov/investigations/AccidentReports/Reports/...
| - its interesting: Planes back then had an emergency oxygen
| system that worked on the same principles like the candles
| mentioned above, but these were much smaller. The crashed plane
| transported discarded / expired oxy generators in loose
| cardboard boxes since they were not labled as hazardous
| materials. One of theses generators was probably the cause for
| a chain reaction and the crash.
| bartchamdo wrote:
| https://www.oclugo.com/our-products/chlorate-candles/
|
| This provides accurate info on specifications and the details
| about these candles/devices from a different manufacturer.
| Including % of particulates.
| nielsbot wrote:
| Smarter Every Day did an interesting series of videos about
| nuclear submarines.
|
| They use these candles to help replenish the oxygen in them:
| https://www.youtube.com/watch?v=g3Ud6mHdhlQ
| fmakunbound wrote:
| At the end of the movie about the Kursk, someone drops one in
| water accidentally and it seems the air ignites afterwards. Are
| these candles the same thing?
| mothsonasloth wrote:
| That was a potassium or alkali metal oxide that reacted with
| the salt water and exploded
| belorn wrote:
| Potassium superoxide which acts as an CO2 scrubber, oxygen
| generator and dehumidifier in one. It reacts violently with
| water, and since it produce massive amount of heat and
| oxygen, it will also cause an explosive fire if the
| reaction occur near a fuel.
|
| In Kursk it is suspected that it got dropped into water
| that had a lot of oil floating on top.
| pottertheotter wrote:
| I just watched that today! Super interesting set of videos. I
| highly recommend watching them.
| rdl wrote:
| Most interesting part for me was the basically continuous
| education aspect for everyone on board, as well as the very
| frequent drills. I guess a combination of keeping people
| educated/trained _and_ avoiding idleness in such an
| environment for months at a time.
| rplnt wrote:
| I'm kinda torn on this. On one hand it's super interesting,
| on the other it's state-sponsored army propaganda series,
| luring in young Americans, painting everyone in service as a
| hero.
| bityard wrote:
| I was in a different branch but I feel like the series was
| probably a remarkably balanced portrayal of Navy/submarine
| life. There's a lot of cool stuff to talk about but clearly
| it's a demanding job and most of those sailors looked worn
| right out.
| formerly_proven wrote:
| Oh no, a clearly labelled piece of entertaining
| advertisement, how awful.
|
| Also... even these show how difficult life on a submarine
| is (and the ultra-wide angle used most of the time shows
| how extremely claustrophobic everything is). Not exactly
| appealing. It takes some very special people to do this
| kind of job, and I doubt a lot of people are cut out for
| it...
| thescriptkiddie wrote:
| You underestimate how big a role the "cool factor" plays
| in recruitment. Note how propaganda always focuses on
| jets and tanks and submarines and aircraft carriers and
| futuristic gadgets, and when they do feature an soldier
| it's always a badass tier-one operator who gets to flaunt
| the uniform code. Seventeen-year-olds don't get so
| excited about the prospect of burning literal shit in a
| hole behind some godforsaken checkpoint in Afghanistan
| until one day an IED takes their leg off.
| nickelpro wrote:
| As mentioned in the video, candles are a backup/supplemental
| form of oxygen generation. Older platforms will have an AEOG
| (Automated Electrolytic Oxygen Generator), popularly known as
| "the bomb", and newer platforms will have the substantially
| safer LPE (Low-Pressure Electrolyzer).
|
| Burning candles is a hassle and creates a big mess, to the
| consternation of junior enlisted who have to haul clinkers
| around and clean up the constant dust storm they leave behind.
| That said, huffing that good O2 straight out the spout will
| keep you awake, especially if your boat has been below 18% for
| awhile.
| imwillofficial wrote:
| I remember A gang telling me how explosive the whole AEOG
| process was when I checked in. It literally is a potential
| bomb.
| nickelpro wrote:
| They used to be worse! The original 6L16 EOG didn't have
| the "A". It was neither Automated nor Advanced, the only
| "A" it had was operated by A-gangers!
|
| 3k-lbs of pure O2 combined with a reputation for fires,
| rapid depressurizations, and hydraulic leaks. More than one
| auxiliaryman got blasted to bits by those things back in
| the '60s. Every submariner thinks theirs is a unique and
| special hell, but I don't envy those who went underway with
| the old O2 plants.
| ChuckMcM wrote:
| For fun, I went looking to see if you can buy one. In theory, you
| can buy them here: https://www.oclugo.com/our-products/chlorate-
| candles/)
|
| I'm guessing the best place to find them would be a military
| surplus dealer.
| ChrisMarshallNY wrote:
| I remember these critters, from the 1970s:
| https://en.m.wikipedia.org/wiki/SolidOx_(welding)
| londons_explore wrote:
| It's notable that _humans cannot detect_ low oxygen levels.
|
| Tasks become harder and you make worse decisions, but at no point
| will you think "I need more oxygen, better light the candle".
|
| On the other hand, high CO2 is pretty detectable. You'll start to
| find the air 'stuffy' and it will be immediately obvious there is
| something wrong with the air.
| tialaramex wrote:
| Even high CO2 - which your brain does detect - won't be
| detected fast enough by your brain to do anything useful about
| changes that arise very suddenly, because the sensor is
| measuring your blood, and high blood CO2 can mean you're
| seconds away from unconsciousness but with impaired cognition.
| You're screwed.
|
| Humans will clamber down into a space that's been flooded with
| CO2 (to fight fires or by mistake), go, huh, that's not...
| er... bonk, and lose consciousness. Then others up top are
| likely to climb down to "save" the people who just fell over
| for no reason and suffer the same fate.
| _Algernon_ wrote:
| Are you sure those cases are CO2 and not CO? Iirc CO is the
| truly fucked up one because it binds to hemoglobin much more
| readily than CO2 thus displacing both CO2 and O2 in the
| blood.
| tialaramex wrote:
| With Carbon _Monoxide_ there 's a big risk of gradual
| poisoning. For example if you run a stove in a sealed
| compartment to keep warm, well, the Carbon _Monoxide_
| released can 't escape and will gradually poison you over
| even several hours. If your body had a CO sensor, you'd
| realise there was a problem in plenty of time to flee,
| because it's so gradual, but it doesn't and so you might
| feel a little sleepy and that's it, you're probably never
| going to wake up.
|
| With Carbon _Dioxide_ that gradual risk doesn 't exist, you
| would realise there's a problem. You will probably even be
| woken if CO2 gradually rises, you'll become conscious,
| discover the air seems "stuffy" and go somewhere with fresh
| air.
|
| The problem in the drastic CO2 scenarios is it's too
| sudden. It's understandable (more so than with Carbon
| Monoxide) that we didn't evolve to cope with that.
| Prehistoric man did not use CO2 fire extinguishers.
| agurk wrote:
| With CO the issue is that it binds to haemoglobin and stays
| bound to it permanently. Only a small proportion of CO2 in
| the blood is bound to haemoglobin (~10% [0]) so the real
| issue is that the O2 carrying capacity is reduced. As red
| blood cells are constantly being replaced limited exposure
| is not a long term issue, but this is a process that takes
| weeks. This means that someone with acute exposure cannot
| be helped with supplemental oxygen (or just being taken
| outside) unlike with CO2.
|
| CO2 in high concentrations causes issues through various
| mechanisms with a major one being that it impairs your
| ability to absorb O2 and other cellular disruption through
| increasing the pH of your blood [1]. This can cause
| unconsciousness in seconds at high concentrations and other
| potentially fatal impairments even at lower levels.
|
| So CO poisoning is worse as there's no (easy) therapy for
| it but it is still very possible to have fatal exposure to
| CO2 if you are not able to receive fresh air in a immediate
| time frame (minutes).
|
| There is also the general issue that confined spaces might
| be low on O2 as well, as described in this video on
| confined spaces in ships [2].
|
| [0] https://www.ncbi.nlm.nih.gov/books/NBK532988/
|
| [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5380556/
|
| [2] https://www.youtube.com/watch?v=uNVj_JpZia8
| NickNameNick wrote:
| This happened on a log carrying frieghter near here, a few
| years ago.
|
| The unprocessed logs in the holds are slowly rotting, so the
| air in the holds can be depleted of oxygen.
|
| A crewman went into the hold to check on something, and
| collapsed. Another crewman went in to rescue the first, also
| collapsed. I don't recall how many went in, but eventually
| someone grabbed an oxygen tank and managed to save the last
| one. The rest died.
| hnbad wrote:
| I've watched a presentation on this problem that showed
| surveillance footage of this exact kind of situation
| happening and costing the lives of at least two people (I
| think the fourth one realized what was going on and got
| geared up before saving the last one to go in before him).
| You could watch them simply drop like flies, it was obvious
| they didn't realize what was happening to them before they
| fainted.
| rocqua wrote:
| Is this because we don't feel out of breath by lack of blood
| oxygen, but by an excess of blood CO2? Also related to
| hyperventilating causing fainting because you scrub out CO2 and
| hence think you have plenty of oxygen, and the use of a paper-
| bag to re-circulate some of the CO2 to keep blood levels of CO2
| high enough.
| t0mas88 wrote:
| A dropping level of CO2 from hyper ventialtion also disturbs
| the acid-base balance in the blood which in itself can cause
| dizziness, impaired mental function and tingling fingers as
| if you have a lack of oxygen.
|
| At high altitude it's easy to mistake this for hypoxia (due
| to loss of pressure), because the feeling and visible
| symptoms can be very similar.
|
| The distinguishing symptom is seeing blue lips/fingers, that
| doesn't happen with hyperventilation. But if you've taken
| hypoxia that far you're in a lot of trouble.
|
| Recommended approach for flight crews is to not bother
| figuring out whether it's hypoxia or hyperventilation but
| instead for everyone to put on oxygen masks, verify each
| other's masks and focus on breathing normally. It will fix
| both issues and ensures that the rest of the crew is fine in
| case it was hypoxia.
| pmoriarty wrote:
| _" A dropping level of CO2 from hyper ventialtion also
| disturbs the acid-base balance in the blood which in itself
| can cause dizziness, impaired mental function and tingling
| fingers as if you have a lack of oxygen."_
|
| Hyperventilation is also at the core of _Holotropic
| Breathwork_ , which people deliberately do to get
| psychedelic effects:
|
| https://www.holotropicbreathworkla.com/how-to-do-
| holotropic-...
| matsemann wrote:
| Yes. If you try to hold your breath, the pain you feel is
| from CO2 buildup, not because of a lack of oxygen. If you lie
| still, the oxygen would last for many many minutes, but most
| people will be in such a pain after a minute or two that the
| body refuse to keep holding the breath.
|
| Consequently, that's why hyperventilating is absolutely a no-
| go when freediving. It tricks your body, by not triggering
| the CO2 feeling. So then you can suddenly pass out without
| feeling you were close to running out of air.
| rocqua wrote:
| Is, at the same time, hyperventilating an effective (but
| very dangerous) way for people to get better at freediving?
| It seems like it would help people get deeper, especially
| when they are no where near their limits. That also sounds
| like it would make things even more dangerous, because when
| you get better and do get near your limits, you don't
| notice.
| matsemann wrote:
| For most people, I think the increased heart-rate of
| doing the big breathing motions would nullify the
| theoretical gain. So it feels easier, but you can't
| really hold any longer, you just pass out unexpectedly.
|
| The best way to get better is to do "co2 tables", just
| slouch in your couch and do the intervals of
| breathing/holding, and learn to control your body. When
| actually diving, we never push our limits, compared to
| what we know we can handle on land. Like, I can hold my
| breath for 5 minutes, but would seldom be more than a
| minute underwater.
|
| Co2 tables are actually very meditative. After the first
| convulsions, if you manage to calm your body down, it's
| quite a weird headspace to be in for the next minutes.
| nickpeterson wrote:
| I'm missing something, it says these burn at 1100 degrees. There
| is no oxygen but enough space for me to be ok burning something
| at 1100 degrees next to me?
| acquacow wrote:
| That really depends on the density/surface area of the item. I
| mean, a standard light blub filament burns at like 3000F, but
| you don't really feel that.
| lapsis_beeftech wrote:
| It sounds like a lot but it is about the same temperature as
| that of a regular wax candle flame.
| oasisbob wrote:
| In 1997, a chemical oxygen generator failed aboard the Mir space
| station, and caused a pretty nasty fire:
|
| https://en.m.wikipedia.org/wiki/Vika_oxygen_generator
|
| https://www.nasa.gov/pdf/602090main_44s_international_life_s...
| notadev wrote:
| For decades the US Navy used the OBA[1], or Oxygen Breathing
| Apparatus, for fire-fighting, which also worked using a sodium
| chlorate candle. I had only ever used them in boot camp, as when
| I got to the fleet they were starting to switch over to SCBAs --
| what actual fire-fighters use on land. I was always terrified of
| the thought of having to use one in because I vaguely recall
| something about them potentially exploding if they got too wet
| which seemed almost guaranteed being on a ship in the ocean.
|
| A few years ago, maybe 2015 or so, I was walking through base on
| my way home and saw a moored tugboat was on fire. The two guys on
| board were in OBAs trying to put it out while waiting for the
| base FD to show up, so I suppose they're still used in some
| places.
|
| [1] https://en.m.wikipedia.org/wiki/Oxygen_breathing_apparatus
| swamp40 wrote:
| Mars
| ck2 wrote:
| This is blowing my mind, probably envisioning the wrong size of
| the candle for this kind of output:
|
| > _The candle supplied by MineARC Systems burns for approximately
| 60-90 minutes, producing 2600L of oxygen. This amount can provide
| approximately 20 hours of breathable air for four people. An
| oxygen candle cannot have its oxygen production regulated or
| halted and once ignited; it produces oxygen at a rate of
| approximately 28 Litres per minute until it is exhausted._
|
| Oh I see now, it's that big metal cylinder on the floor, they are
| going to pour the powder into it and ignite?
|
| https://minearc.com/wp-content/uploads/2021/01/cristel-train...
| joosters wrote:
| I'm also struggling to get an idea of the size of the candle;
| the article gives no information and it's unclear if the photos
| of the demo are using the same product as described in the
| text. Surely something that can produce 2600L of oxygen must be
| pretty big? It's a shame that the page gives no clue as to the
| size and weight.
|
| Another page details a 'rugged oxygen generator' -
| https://minearc.com/products/emergency-response-products/rug...
| that produces 90L of oxygen over 15 minutes, and that is 115mm
| x 284mm, weighing 2.3kg. Confusingly, the PDF of the product
| specs shows that it comes with a mask - so 90L of oxygen is for
| one person, for just 15 minutes here? And if used with a mask,
| is it actually pure oxygen being produced, or breathable air
| (where does the nitrogen come from?) I'd love to know more, but
| the website doesn't tell us.
| aspectmin wrote:
| Average human: breathes approximately 7 liters per minute of
| air, give or take @ 21% oxygen. Maybe 22L of oxygen under
| normal respiratory demand. More if under stress of course.
|
| At 100% oxygen that's 105L of O2? So guesstimating almost
| 100% O2?
|
| Source: am paramedic, not doctor or respiratory therapist.
| kzrdude wrote:
| Breathed air is diluted right, to some lower % of oxygen
| content, but it needs to be in the calculation.
| urban_winter wrote:
| Exhaled air is about 17% oxygen, 4% carbon dioxide. So,
| as previous poster noted, scrubbing the CO2 is your first
| priority. You can't breathe air with greater than about
| 4% CO2 indefinitely. Oxygen levels lower than 15% are
| also bad.
|
| Diving rebreathers are an interesting implementation of
| these rules in that they are lethal if you get it wrong.
| arrosenberg wrote:
| It's not ignited, this is how airplane oxygen systems work. A
| phosphorus match provides the activation energy (as heat),
| which causes the decomposition of Sodium Chlorate (NaClO3) to
| Sodium Chloride (NaCl, table salt) and free oxygens. The
| oxygens combine to form atmospheric oxygen (O2).
| nickelpro wrote:
| At standard conditions, a single mole of oxygen occupies 22.4L.
| The conversion rate from NaClO3 to O2 is 2-to-3, so for every
| two moles of sodium chlorate you burn, you get three moles of
| Oxygen, or 67.2L.
|
| The molar mass of NaClO3 is 106.44g.
|
| So some quick math, to fill 2600L we need 116 moles of oxygen,
| which we can produce with 77 moles of sodium chlorate. Multiply
| by the molar mass and we get ~8kg.
|
| Sodium chlorate has a density of 2.49 g/cm^3, so an 8kg slug
| will fit in a 3.2L bucket.
|
| 3L of powder gets you 2600L of oxygen, not bad!
| manholio wrote:
| He did the math, what a legend.
| VaxWithSex wrote:
| Thanks, I attempted to do the calc in my head... and it's
| been to long, that I learned Chemistry in school apparently.
| nickelpro wrote:
| What this boils down to is "salt is a couple orders of
| magnitude more dense than air, so we can fit a lot of air
| in very little salt". Which is a sentiment I think most
| people can _feel_ is correct even if they don 't know their
| ideal gas law or whatever.
| kolinko wrote:
| This website has claims falsely that oxygen tanks need co2
| scrubbers and candles don't. That is not true and can get people
| hurt!
|
| You need co2 scrubbers for any oxygen producing solution, since
| co2 kills faster than o2 scarcity.
|
| Having a candle, and just a candle alone in a hermetically sealed
| room will result in suffocation as fast as without it.
|
| I reported the post as it contains false and dangerous info.
| bell-cot wrote:
| I disagree, for contextual reasons. Oxygen candles are an
| emergency safety supplies item for people who get serious
| training in industry- and facility-specific safety procedures.
| Notice the slant to the headings, language, photos, etc. on the
| page. This is _very_ clearly not a consumer product, and
| phrases such as "Used as the last means of breathable air
| within a refuge chamber..." really don't suggest "try this at
| home, kids!".
| danuker wrote:
| The page doesn't _technically_ say that candles don 't
| require scrubbing. Candles also require scrubbing. But the
| disadvantage is omitted from candles, while explicitly
| presented for cylinders:
|
| "Oxygen cylinders are used in the event compressed air fails
| and generally require the support of a scrubbing system to
| remove carbon dioxide [...]"
|
| Oxygen cylinders are also used as an emergency non-consumer
| product. The comparison is a misleading one.
| modec wrote:
| But there is also an oxygen candle above every seat in
| passenger airplanes, right? Then it would be a consumer
| product ...
| [deleted]
| dividedbyzero wrote:
| I think that's stretching the definition of consumer
| product to the point of losing its usefulness. A lot of
| (semi-)automated emergency tech contains seriously
| dangerous stuff, like explosives or highly toxic materials,
| and these devices are usually very carefully engineered to
| keep the risks from using that tech acceptable even under
| emergency circumstances, and risk tolerance tends to be a
| lot higher for a device meant to be used in a decompressing
| plane in the first place. You can't use that oxygen candle
| outside such a situation, and you can only use it through
| the extremely constrained user interfaces provided by the
| yank switch and mask.
| modec wrote:
| Ok fair. I just thought that it proved that they could be
| made safe. I now realize that emergency situations have
| very different tolerances for safety.
| throwawayboise wrote:
| The oxygen generators in an aircraft are only designed to
| provide emergency oxygen if cabin presurization is lost,
| until the pilots can descend to breathable atmosphere
| (under 10,000 ft). I.e. maybe 10 minutes or so. There
| will be no dangerous accumulation of CO2 in that time,
| hence no need for scrubbers.
| a1369209993 wrote:
| If cabin presurization is lost, there will be no
| dangerous accumulation of CO2 _period_ , because it leaks
| out through the non-airtight seal between the oxygen mask
| and your face. The emergency oxygen is more about
| providing a breathable partial pressure of oxygen (~0.2
| atmosphere IIRC) when the total pressure is much lower
| than sea level, by greatly increasing the concentration.
| bell-cot wrote:
| This.
|
| Similar - a residential electrical service panel. It's
| generally okay for even a little kid to flip a wall-
| mounted light switch. Touching the circuit breaker
| handles on the service panel is a "competent adults,
| paying close attention, only at need" activity. And
| digging inside that service panel should only be done by
| professionals.
| quesera wrote:
| > Touching the circuit breaker handles on the service
| panel is a "competent adults, paying close attention,
| only at need" activity.
|
| This is not accurate.
|
| Circuit breakers are just lightswitches with the ability
| to switch themselves OFF.
|
| The larger breakers (you mention "handles" instead of
| "switches") are the same, although rated for higher
| current than typical household lightswitches.
|
| The breaker panel is just a grounded metal box. It is not
| dangerous to touch, except in fault cases where the whole
| building has dangerous power.
|
| And just like you should not unscrew a lightswitch cover
| unless you know what you're doing, you should not unscrew
| a breaker panel cover.
|
| Same rules -- but if you break them, the difference
| becomes important: Inside the breaker panel, it's
| possible to come into contact with higher current sources
| than inside a lightswitch box.
| jimmaswell wrote:
| A breaker has bare live metal exposed inside that will
| shock you if you touch it. Maybe newer designs don't, but
| mine does.
| quesera wrote:
| Right, just like a lightswitch. But in both cases, only
| if you open the protective enclosure with a screwdriver.
| jimmaswell wrote:
| Mine has no such enclosure, just a door that takes no
| tools to open.
| quesera wrote:
| That might be a 1960s-70s-era Zinsco.
|
| If so, you should get it replaced right away. Easy access
| to the internals is the least of your concerns -- these
| panels are unsafe as designed, and responsible for much
| fire and death.
| dylan604 wrote:
| Yikes! Did this pass an inspection like that? I'd highly
| suggest moving this higher up on the TODO list. Whether
| its a panel that needs replacing or just a cover needs to
| be replaced, it should be corrected. Please, don't become
| a statistic! </randoInternetNanny>
| jimmaswell wrote:
| I have no idea when's the last time an inspector saw this
| place. It's a mobile home manufactured in the 60s so a
| lot of lax code is probably grandfathered in. The panel
| is too high and out of the way for a child to reach and
| I'm smart enough not to touch it. I imagine whoever I
| sell the house to is going to demolish it anyway.
| jyounker wrote:
| In other words, contemporaneous with the Chevy Corvair,
| and pre-dating most modern safety regulations.
| dylan604 wrote:
| Hey! I liked my Corvair. I learned how to drive in a
| Corvair. It was also the car father/son project where I
| learned I had no interest in being a grease monkey.
| dkarl wrote:
| You're right, but given that some people subject their
| breaker boxes to amateur fiddling, leaving loose or
| missing covers and poorly done wiring, I sympathize with
| his point. I wouldn't send a kid to flip a breaker unless
| it was my own house and I knew the breaker box was safe.
| I realize that in theory a light switch can be unsafe
| just like a breaker box, but in practice, I would never
| worry about sending a kid to flip a light switch.
| quesera wrote:
| Fair enough. I would never live in a house that had
| sketchy service panels, and in an unknown/presumed-
| dangerous environment, I'd never send an inexperienced
| person to mess with service panels (or lightswitches) I
| hadn't inspected myself.
| [deleted]
| throwaway0a5e wrote:
| >Touching the circuit breaker handles on the service
| panel is a "competent adults, paying close attention,
| only at need" activity.
|
| Kindly screw off with the FUD peddling.
|
| You should be able to flip breakers all you want without
| doing anything more than annoying people by interrupting
| whatever those breakers were powering.
|
| A breaker panel is designed so that you need to get out a
| screwdriver and remove fasteners to get near anything
| that might hurt you.
|
| Unless someone is actively working on a circuit <insert a
| bunch of low effort comments about the virtues of lock
| out tag out here> you shouldn't be able to hurt anyone or
| anything by flipping a breaker on or off. Breakers
| protect the wires. Devices are responsible for their own
| protection. Incomplete circuits get capped to prevent
| shorts to ground or elsewhere.
| bell-cot wrote:
| At small scale, either living alone or with a few other
| responsible adults, you're pretty much correct.
|
| But you've never had grandkids who got interested in
| playing with the breaker panel, have you? Nor almost
| gotten yourself electrocuted, when you trusted a "not
| quite so sharp as they once were" older relative to turn
| off the specific 20A circuit that you were working on?
|
| Also worth noting - residential circuit breakers, even
| new (vs. decades-old plastic that's getting kinda
| brittle) are often rated for vastly fewer on/off cycles
| than even the crappiest old wall-mounted light switch.
| quesera wrote:
| Well, if you're working on the wires, lightswitches can
| be just as dangerous as breaker panels.
|
| Don't ask incompetent electricians to help you with
| electrical work. Check!
| rootusrootus wrote:
| > lightswitches can be just as dangerous as breaker
| panels
|
| That's very much not the case. A light switch, at least
| in the US, is just 120V. Sure, it could kill you, but
| 99.999% of the time it'll just annoy you if you touch the
| hot wire inadvertently. You can easily get 240V inside
| the panel, however, and on top of that you can easily get
| it at 200A. I'm a _lot_ more careful when I 've got the
| panel cover off for any reason.
| tlb wrote:
| There isn't 240V to ground, which is the usual path for
| shocks. To get 240V through your body, you'd need to
| touch two hot wires at the same time. And you feel it
| when you touch the first one, so I think this is rare.
| You should be working with one hand most of the time.
|
| The 200A is a danger. A direct short from a bus bar to
| ground can peak at 1000s of amps before the main breaker
| blows.
| quesera wrote:
| True, and of course it only takes a small fraction of
| _one_ amp to cause harm to a human, if the path of the
| current crosses your heart or lungs.
|
| 240V at 200A would burn you crispy, but it's a bit
| challenging to get to.
|
| 120V at a fraction of 1A can disrupt/stop your heart, and
| it's _easy_ to get inside a service panel.
| quesera wrote:
| OK, but no one is talking about working on the inside of
| panels.
|
| It's been clear throughout the thread, but yes -- don't
| open breaker panels and work on them casually.
|
| Flipping a breaker in a closed, code-compliant panel is
| exactly as safe as flipping a lightswitch in a closed,
| code-compliant wall box.
| rootusrootus wrote:
| > OK, but no one is talking about working on the inside
| of panels.
|
| I must have misunderstood, then -- you said light switch
| wiring is as dangerous as breakers, and breaker wiring
| can only be found inside the panel.
| quesera wrote:
| It won't be particularly rewarding, but if you go back
| through the history you will see the full context.
|
| It involves the safety of requesting an inexperienced
| person to flip breakers.
| rootusrootus wrote:
| Sure, I get that. But the wiring in a panel is just as
| hidden as the wiring of a light switch.
| Ensorceled wrote:
| I agree, kids and senile seniors should be kept away from
| the breaker panel.
|
| But that wasn't your original assertion, stop moving the
| goal posts.
| serf wrote:
| >A breaker panel is designed so that you need to get out
| a screwdriver and remove fasteners to get near anything
| that might hurt you.
|
| you hope.
|
| zinsco breaker panel boxes are still commonplace in the
| united states on older properties; they require no
| fasteners to open up and are (mostly) bussed in such a
| way that they're extraordinarily dangerous when open.
|
| Still, I agree with the spirit of your message -- but
| let's be clear, household electrics _are_ dangerous, and
| not every breaker panel is going to be designed with
| safety in mind.
| galangalalgol wrote:
| Two of the last three houses I've lived in had front
| panels that no longer fit, so you needed to take care
| when operating the breakers. In the older one, we tripped
| a breaker and about half the lights in the house went
| out. I went hunting for it and eventually went to flip
| off the main to start a more thorough check, only to find
| that is what had tripped, leaving half the house on...
| About half my 120 and all my 240 breakers were wired
| direct to the bus bypassing main. I'd love to hear a
| pro's stories. I bet they see really weird and terrible
| stuff.
| quesera wrote:
| FWIW: Poorly-fitting panel covers would never pass an
| inspection and are inherently dangerous. It's really
| important for the panel to be enclosed. Humidity, dust,
| vermin, and fingers get in. Sparks get out. Your home
| insurance would be worthless in case of a fire. Never
| mind the risk to irreplaceables.
|
| But re: tripping the main -- this is likely a fault in
| the breaker itself. It's not likely that a faulty line
| breaker allowed enough current to trip the mains breaker
| (though it does happen, but see below). Of course several
| overloaded lines can trip the mains, but this is
| exceedingly rare. A fault in the mains breaker is a
| serious problem for sure. However, unless you inspected
| the wiring yourself, I'd hesitate to assume that it was
| miswired as you describe.
|
| In standard US residential service, you get two 120V
| lines ("legs"). If the mains breaker failed, it's
| possible to lose one of those legs to the buss that
| supplies the line breakers (and the house fixtures),
| while the other leg stays up and powering the "other
| half" of the house. In this case, 240V appliances will
| appear to be "out" because they are only getting partial
| power (240V is really just two 120V services, 180degrees
| out of phase).
|
| So I'd guess the cause was a failed/fatigued mains
| breaker. That's a job for an electrician, regardless, who
| would surely notice miswiring if present, and the other
| code violations that you definitely had.
| mindslight wrote:
| Couldn't it also be a really old style of panel without a
| singular main breaker, either falling under the "rule of
| 6" or perhaps dating from before it?
| galangalalgol wrote:
| The inspector did fail it, and has failed every house
| I've ever had inspected. The inspectors for my buyers
| also failed it. People just kind of live with it on old
| houses. Never thought about it making an insurance claim
| fail. So the main breaker only turns off one leg? Why
| wouldn't you have one for each.
| quesera wrote:
| The mains breaker controls both legs, but they are
| separately protected. So if a protection sensor fails, it
| might only interrupt one leg. The switch controls both
| legs though.
|
| I've done a lot of electrical work in old houses, but
| only in big cities where a failing inspection is just not
| tolerated. I've seen old country homes where regulation
| is ... less strict. This might not be an urban/rural
| divide, but that's my experience having lived in both.
|
| I'm amazed that you were able to buy or sell a house that
| did not pass inspection. If the buyer was financing, the
| mortgage would require insurance, which would require
| inspection. In a cash sale, the buyer should be
| sophisticated enough to take responsibility for the
| repairs.
|
| I think (in my high-regulation states) it's actually not
| legal to sell a house that does not pass a safety
| inspection. At least not without surrendering the
| certificate of occupancy until repairs are completed and
| inspected.
| galangalalgol wrote:
| These houses have all been in the DFW metroplex, so low
| regulation TX. The people that bought the terrifying
| breakerbox had a first time homeowner loan and the lender
| complained about some of the vegetation being too close
| to the house, but somehow the box was ok. I turned the
| main breaker on and back off, and half the lights were
| still in. Weird one. All the outlets that had a ground
| hole were actually grounded, most of my friends have
| houses with fake grounds, knob and tube or worse,
| aluminum wiring. Regulations are sometimes a good thing.
| Its probably why our houses are cheaper though.
| quesera wrote:
| Some Zinsco panels do require fasteners.
|
| The faultiness of Zinsco panels are not a special concern
| with flipping the breakers. They're just faulty. And you
| don't even need to open them to be dangerous, they have
| corrosion and heating problems.
|
| > not every breaker panel is going to be designed with
| safety in mind.
|
| Well, to be fair -- of course they were _designed_ with
| safety in mind. They just failed.
|
| But yes, replace any Zinsco panels! Also some Federal
| Pacific and Challenger/GTE-Sylvania panels. This should
| be caught in a home inspect, and most home insurance
| companies will make it a requirement of coverage.
| meepmorp wrote:
| People get surgery every day, does that make the surgical
| instruments that are used, consumer products?
| modec wrote:
| No. Sorry I was wrong.
| meepmorp wrote:
| Jesus, I swear I haven't heard anyone say that on the
| internet in over a decade. Unironically, thanks.
| ineedasername wrote:
| By that reasoning the chemical explosive inside a car's
| airbag is also a consumer product. Same for toxic
| carcinogenic rhodium found in catalytic converters. I could
| go on.
|
| Just because something in a consumer product does not mean
| that thing, by itself, is a consumer product. Or at least
| us using the term "consumer product" is stretched near the
| breaking point if you look at things that way.
| modec wrote:
| Yes. Sorry I was wrong.
| NickRandom wrote:
| See https://en.m.wikipedia.org/wiki/Emergency_oxygen_system
| for details on the two types of systems used (not an
| expert, just duck-ducked it out of curiousity). Yes - there
| is (sometimes) an oxygen candle above each seat. Does that
| make it a consumer product? I'm not sure and no opinion on
| that aspect, I mainly included the link for those
| interested in how they work. To coin a phrase 'Now I know'.
| rdl wrote:
| I don't see where it claims that.
|
| They point out that piped air is one option (which is basically
| continuous open circuit in these settings; exhausting to
| outside.). The alternative is oxygen cylinders mounted on the
| chamber (or inside the chamber), which (generally) require
| scrubbers.
|
| Oxygen candles are then mentioned; they are essentially a
| nearly direct replacement for oxygen cylinders, but with
| somewhat better storability. It is silent on whether co2
| scrubbing is needed, but obviously would in the same settings
| oxygen cylinders would.
| SapporoChris wrote:
| "A candle is an entirely independent source of oxygen from
| within the refuge chamber. In this way, it's isolated from
| common faults found in the other sources:
|
| Compressed Air: The feed can often be compromised during an
| emergency due to damage to the circuit or carbon monoxide
| contamination requiring the chamber to be isolated."
|
| The candle is not isolated from the common fault of carbon
| monoxide contamination. Both Oxygen candles and oxygen
| cylinders will generally require scrubbers.
| lultimouomo wrote:
| I think you are mixing up carbon monoxide contamination and
| carbon dioxide build up.
|
| They mean that with oxygen candles you don't risk having
| your very oxygen reserve introduce carbon monoxide in the
| air you breathe, as it could happen of you have a
| contamination at the source of compressed air.
| SapporoChris wrote:
| Okay, ignoring carbon monoxide contamination. The site
| also states: "Oxygen cylinders are used in the event
| compressed air fails and generally require the support of
| a scrubbing system to remove carbon dioxide and carbon
| monoxide from the air."
|
| If Oxygen cylinders generally require a scrubber I think
| it's safe to assume that a Oxygen candle will also need a
| scrubber.
|
| They list issues with other systems but don't acknowledge
| the same problems that exist with their own.
| [deleted]
| foxyv wrote:
| This is correct. A person in a hermetically sealed suit will
| die of CO2 poisoning a long time before Oxygen deprivation.
| However in most mines, they will engineer gas permeability so
| that CO2 and other poisonous gasses can seep to areas with
| lower concentrations and out of the mine. Coal mines seem to be
| particularly bad with regards to permeability.
|
| In this case, an Oxygen candle _MAY_ be enough to keep people
| alive. However, why O2 tanks would need scrubbers and candles
| wouldn't doesn't make any sense.
|
| https://www.hindawi.com/journals/ace/2018/3976505/
|
| https://www.cdc.gov/niosh/mining/works/coversheet1621.html
| throwawayboise wrote:
| False and dangerous to whom?
|
| Anyone in a position to be using oxygen candles or bottled
| oxygen in a survival shelter setting is likely to have had
| safety training in how to use them, and if it is a situation
| where CO2 concentration is likely, that should have been
| accommodated in the construction of the refuge or shelter.
| xenadu02 wrote:
| > in a hermetically sealed room
|
| I thought these chambers have pressure-triggered relief valves
| and rely on elevated pressure in the chamber to force air out?
| Basically dumping some of the existing air/gas in the chamber
| which carries away some CO2 with it.
| aaron695 wrote:
| FieryTransition wrote:
| Yeah, unless you need to stay silent for detection reasons or
| warfare, my guess would be that in a fixed facility, it would
| be way cheaper and reliable to have a positive pressure or
| flow of air going outward. I've seen windows and buildings do
| this completely passive, so a modern design would only have
| this as an absolute emergency, as they are dangerous and
| doesn't solve the Co2 problem.
|
| Don't see how this is relevant for civil use though, but hey,
| maybe some paranoia can sell some candles.
| swixmix wrote:
| Oxygen candles smell bad. I would never want to use one except
| in an emergency situation. No scrubber necessary if I'm just
| evacuation.
| bryanrasmussen wrote:
| Is there such a thing as a portable c02 scrubber - other than a
| plant?
| rootusrootus wrote:
| Wasn't that one of the things Apollo 13 had to figure out how
| to rig up in order to survive?
| frederikvs wrote:
| Yes, e.g. if you look at "rebreather" diving equipment, it's
| essentially a backpack life support system, including CO2
| scrubber.
| rdl wrote:
| Yeah -- soda lime, etc. e.g. https://minearc.com/remove-co-
| co2-in-refuge-chamber-chemical...
| bookofjoe wrote:
| Yes. There is a soda lime canister integrated into the
| design of anesthesia machines.
| JoshTriplett wrote:
| Are there solutions for CO2 scrubbing that use electricity
| and can run indefinitely, rather than chemical substrates
| that get used up and require replenishing?
| elihu wrote:
| One method if you have enough electricity is to capture
| some amount of air from the room, compress and/or
| refrigerate it until the various gasses liquefy (they
| each liquefy at a different temperature/pressure), and
| drain off each liquefied gas that you want to separate
| into its own container.
|
| At least, that's how the CO2-filtering device described
| in The Martian worked. I'm not sure if anyone uses that
| system in real life. Apparently on the ISS they use
| filters made of zeolite[1]. From that article though it
| didn't say if the filters were reusable. If they are,
| maybe just using filters is good enough for quite a long
| time.
|
| [1] https://www.syfy.com/syfy-wire/nasa-launched-an-
| upgraded-co2...
| numpad0 wrote:
| Remember the talks about DIY Oxygen concentrators during
| COVID emergency days, using two pipes filled with zeolite
| beads alternatingly pressurized from pumps and valves so
| to separate Nitrogen in the air and leaving Oxygen in the
| gas? Apparently the same Pressure Swing Adsorption
| principle is used to extract couple other gases as well,
| and CO2 is one of them.
| thescriptkiddie wrote:
| The zeolite filters are regenerated by heating them,
| which causes them to release the captured CO2. This is
| obviously done in a sealed chamber so that the CO2 can be
| captured or vented overboard.
| atrus wrote:
| While probably not as applicable on Earth, the ISS CO2
| scrubbers use a chemical substrate that is then exposed
| to space where the CO2 is sent off.
|
| https://www.eni.com/en-IT/scientific-research/space-free-
| co2...
| rdl wrote:
| Yes, but the context of this post was emergency systems
| which are purely chemical.
|
| For routine operations on e.g. a submarine,
| https://www.naval-
| technology.com/contractors/materials/atmos...
|
| As other people have mentioned, this is a great
| introduction to the topic:
| https://www.youtube.com/watch?v=g3Ud6mHdhlQ
| frederikvs wrote:
| It looks like Monoethanolamine (MEA) can be reused after
| a regeneration cycle. Of course, you will need somewhere
| to dump the CO2.
|
| https://en.wikipedia.org/wiki/Ethanolamine#Gas_stream_scr
| ubb...
| adrianN wrote:
| Soda lime can also be used after a regeneration cycle. If
| you heat it sufficiently it releases the CO2 again.
| krisoft wrote:
| Sure. The trick is that there are regenerative chemical
| substrates. The material absorbes co2, gets saturated,
| cycled to a different part where it is heated and
| releases the co2 and can be used to capture again. If you
| use electricity to do the heating and cycling you have
| exactly what you asked for.
|
| On the other hand these units are usually not small or
| portable. Here is a press release from a manufacturer:
| https://www.naval-
| technology.com/contractors/materials/atmos...
| swiftcoder wrote:
| And plants are not viable as CO2 scrubbers on small scales.
| It takes _a lot_ of plants to scrub the CO2 exhaled by a
| single human - somewhere on the order of 10 full-size trees!
| TaylorAlexander wrote:
| This would make for a lovely mine if you had 10 full size
| trees inside it.
| ryanmercer wrote:
| _minecraft intensifies_
| malfist wrote:
| Plants are generally net neutral in CO2 consumption. They
| consume CO2 during the day, but when not producing energy
| through photosynthesis, they consume O2 and produce CO2 for
| their cellular respiration.
|
| The net effect is generally, plants release similar amounts
| of CO2 at night as they consume during the day. The
| exception here would be plants that use Crassulacean acid
| metabolism for photosynthesis, which would be a lot of your
| arid native plants.
| jandrese wrote:
| I would expect plants to be CO2 negative while growing
| since they're using the carbon to add to their dry mass.
| Once fully grown I'd expect the plants to be roughly
| neutral.
| elmolino89 wrote:
| Single human produces around 1kg of CO2 per day:
| https://www.sciencefocus.com/planet-earth/how-much-does-
| huma...
|
| Seems that algae are up to 400x more efficient at CO2
| scrubbing than terrestrial plants. See:
| https://newatlas.com/environment/algae-fueled-bioreactor-
| car...
|
| No idea though if such bio-tanks are a viable solution in a
| rather devoid of solar light shelters.
| HWR_14 wrote:
| > You need co2 scrubbers for any oxygen producing solution,
| since co2 kills faster than o2 scarcity.
|
| Given their uses are the space station, planes and submarines,
| cant you just vent some of the atmosphere out since you're in a
| pressurized tube of some kind to lower the CO2?
| rtkwe wrote:
| It's far too expensive to launch new material up to do that.
| It's much better to scrub out the CO2 specifically than to
| throw out mixed gases. If you're just removing CO2 you only
| need to replace it with new oxygen which can be
| electrolicized from water stores but if you're tossing out
| cabin air in bulk there's stuff like nitrogen that's harder
| to replace. The ISS is basically sea level air with 21% O2
| and the rest nitrogen plus trace CO2 and other gasses, that
| nitrogen would be much harder to replace.
|
| With hydrolysis you just have waste Hydrogen to toss which
| could in the future be combined with CO2 from the scrubbers
| to create methane fuel (probably not in significant
| quantities but it closes the cycle on O2 as the Sabatier
| reaction also creates H2O which could feed back into
| electrolysis or drinking.
| samatman wrote:
| Just so we're all perfectly clear, this one poster got upset
| about this website and _reported it for misleading information_
| and this is now the top comment.
|
| The company sells an air scrubber:
| https://minearc.com/products/air-quality-management/life-sup...
|
| I love this place.
| peter_retief wrote:
| They have these "candles" in submarines for emergencies, I was
| told on a submarine tour some years back.
|
| Nice summary of the process.
| waynecochran wrote:
| I wish they had a video demo or at least an image of one burning.
| tyingq wrote:
| Still doesn't show the burning, but shows the setup, inserting
| a red phosphorous igniter, etc:
| https://youtu.be/h7Jonu6cXoY?t=396
| peterpost2 wrote:
| I don't know why but that was incredibly satisfying to watch
| as well as educational.
| jacquesm wrote:
| > the oxygen-producing chemical is sodium chlorate
|
| Stupid question: How is it the sodium chlorate and not the barium
| peroxide that produces the oxygen?
| lgats wrote:
| The candles can enter a state of elevated oxygen (maximum 32%),
| classified as oxygen-enriched. However, the same fire ignition
| risks remain at these percentages, and no additional ignition
| risk is present.
|
| i do not think this is accurate, considering the candle produces
| pure oxygen, this risk would be highly dependent on the
| environment and amount of air
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