EXO packs
 

i was watching the movie the other day with my brother and he brought up a good question.

how much life is in an exo pack? because at the end of the movie when quaritch dies, jake goes for the mask. then neytiri finds him and puts it on...

well in the directors cut edition jake and neytiri find tsu'tey( which is the best part of the movie for me) they are in the forest for awhile.

so the question is how much oxygen is in an exo pack? Or is it that it has a filter which turns the air on pandora into oxyen?

It seemed to be a filter. To me at least.

Neither.

Pandora's atmosphere is composed of far larger amounts of CO2 than Earth's; enough to cause earth animals to asphyxiate and become lethally poisoned by it in minutes.

It also has a large enough concentration of H2S to be poisonous. H2S is extremely toxic to many Earth organisms, and will kill in surprisingly small doses/concentrations. The Exopacks are just portable air cleaners for the humans, with filters that capture H2S/CO2 molecules in a filtration device, which has cartiridges that must be changed out periodically to restore filtration capacity.

The concentrations of O2 in the atmosphere is high enough for humans to breathe, and high enough that the metabolism of Pandoran animals, including the Na'vi, can use it as the basis of their cellular respiration. Proof of this is their red blood, which tends to point towards an iron-based oxygen carrying molecule, like the hemoglobin in human blood.

:love2:

they can last up to 2 weeks before you have to clean the filter. just rinse them with water and they're good to go :)

Yup all in the Activists Survival Guide =D

woah :stare:

I might go read that again...

Lol no Raidens just extremely smart XD

all hail Raiden :stare: haha i was expecting a one word answer and I think i learned more about the atmosphere and such in that post than I ever did in Biology 2 years ago.

where do you find the survival guide?

The exopack is a set of filters and a CO2 scrubbing canister (passes the air through a chemical that absorbs CO2, such as lithium hydroxide or soda lime), albeit one that is a lot more efficient than present-day ones based on the size (actually visible as the cylindrical part on the backpack-type part of the exopack)

The only thing that really needs to be done to keep one working is to remove and clean the filters every month or so, as well as occasional replacement or refurbishing of the CO2 scrubber.

If an exopack was an oxygen supply then it would need a large diving-style tank, which would have to be pressurised, as well as regularly maintained and refilled, and would create decompression problems when entering and leaving buildings and vehicles. A set of filters is easier to build and maintain, and far more practical in an atmosphere with ~20% oxygen.

If the exopack is a filter, what does it have a long hose?

heres the source for said discussion

Talk:Exopack - James Cameron's Avatar Wiki - Sam Worthington, Zoe Saldana

Because the backpack section is where the scrubber and filters are. A mask with both hanging from it would not be comfortable, easy to use or practical.

If the scrubbing canister was an air cylinder, it would only be able to provide air for a few minutes of breathing. Such a capacity would limit them to emergency measures only (which is instead covered by chemical oxygen generators with facemasks, similar to the types used in modern day aircraft which suffer depressurisation at high altitude). An independent air supply would make no sense in an oxygen atmosphere, as rebreathers are used today in potentially fatal CO2 concentrations such as mine rescues in place of them, due to having a longer operational time. A compressed gas cylinder requires adjusting of the gas mix for pressures, extensive training, and large amounts of maintenance and infrastructure to charge and service the equipment, while an exopack needs an occasional filter cleaning and scrubber replacement.

Concept art of a chemical oxygen generator:
http://img687.imageshack.us/img687/304/eosf.jpg