dcs and air usage

[diverrick]

Maybe I am missing something here, so I am looking for clearification on this issue.
I don't dive to DC depths,never have, and don't intend to start, but I have been thinking about part of it, and the charts and tables don't seem to consider this from what I have seen.
I was also wondering on the same thoughts about air integrated computors, VS no AI computors on this same issue.
Here goes:
If two divers go down to... say 100 FSW...(or what ever DC depth you'd like) and diver 1 uses 1 tank of air, and diver 2 (is a air hog) and uses 2 bottles of air, wouldn't diver 2 need more DC time than diver1? This is just an example. I would think that diver 2 has more nitrogen in solution, then diver 1 due to double the air intake.
Also do the AI computers take this additional air usage into consideration? If this is true, then that would mean that AI computers would be a bit safer to use then non AI.
Just asking.

 

[Kaos]

diverrick once bubbled...
Here goes:
If two divers go down to... say 100 FSW...(or what ever DC depth you'd like) and diver 1 uses 1 tank of air, and diver 2 (is a air hog) and uses 2 bottles of air, wouldn't diver 2 need more DC time than diver1? This is just an example. I would think that diver 2 has more nitrogen in solution, then diver 1 due to double the air intake.
Also do the AI computers take this additional air usage into consideration? If this is true, then that would mean that AI computers would be a bit safer to use then non AI.
Just asking.

Very interesting question, to which I never brough much though, until today .

For your example, I wouild guess the reason divers 2 needs to intake twice as much air as diver 1 is because one breath isn't as efficient in supplying his (diver 2) body's need in oxygen as diver 1. The same could probably be said about the "efficency" of introducing N2 into the system. I'm sure that breathing more air means more N2 intake, but I seriously doubt that the diffence is double.

A good dive buddy of mine is 15 years older and and almost double my body weight, and always comes up with less air than I for an identical profile (including tank size). We both dive AI computers, but usually the difference between our NDLs at any given point will never exceeds 4-5 minutes.

So my anwer would be, yes, but mostly no. But I'm very curious to read what others will have to say about this.

 

[MonkSeal]

Kaos once bubbled...
I'm sure that breathing more air means more N2 intake, but I seriously doubt that the diffence is double.

No. The N2 uptake is function of time and pressure (depth). Here are links to previous discussions:

http://www.scubaboard.com/showthread.php?s=&threadid=30240

http://www.scubaboard.com/showthread.php?s=&threadid=19733

containing valuable answers from Dr Deco and Bruce Wienke.

 

[Dr Deco]

Dear Readers:

Air consumption and DCS

The other responders have given links to previous replies to this question. It is a common thought that if you breathe more often then you would take on more dissolved nitrogen. Nitrogen on-gassing is determined at the tissue level by the blood flow to that tissue, and the amount ventilating the lungs does not play a large role.

We tend to think of this gas uptake as if we were drinking water. That is, all that we swallow goes into us. That is not true with ventilation of the lungs; most that goes in is simply sent back out.

Dr Deco

On vacation this week :mean:

 

[diverrick]

Thanks for the reply.
That explains it quite well. I guess I'll have to find something else to keep me up at night thinking about now.;-0