My oxygen concentrator machine arrived yesterday, but there is an issue: although in the specs it says my machine can deliver 90% oxygen, and can deliver 5 liters per minute, it turns out that it cannot do both at the same time.
When set to 90% oxygen, my machine outputs only 1 liter per minute; and when set to 5 liters per minute, it supplies only 30% oxygen. (It did occur to me that this might be the case, and I made mental note to ask about this before buying the machine, but of course I forgot my mental note — brain fog strikes again).
These are the settings available on my machine:
90% oxygen at 1 liter per minute
70% oxygen at 2 liters per minute
50% oxygen at 3 liters per minute
40% oxygen at 4 liters per minute
30% oxygen at 5 liters per minute
At rest humans breathe around 6 liters of air per minute, so at a minimum, you'd really need to more-or-less match this air flow, and that's why 5 liters per minute would have been just about adequate.
So anyone looking to buy an oxygen concentrator, be aware of these issues. I guess it would cost more money to get a machine capable of 90% oxygen at 5 liters per minute.
I am still going to try using my oxygen concentrator, but I will not be able to get the 90% oxygen level I was aiming for. I have also come up with a (rather complex) method that I may be able to employ to get my machine to provide 90% oxygen at 6 liters per minute, so that's something I may try later.
what's the equivalent of 20 mins no supplemental oxygen mHBOT with an oxygen concentrator.
It's hard to do an exact calculation (because of the complexities explained in
this post), but as an approximation, I'd estimate that a mild HBOT session at 1.3 atmospheres without extra oxygen is going to increase blood levels of dissolved oxygen by a tad more than 1.3, so let's say 1.5 times.
Thus to get the same effects from an oxygen concentrator at normal pressure, given that the oxygen concentration in air is normally 21%, you would have to be breathing 21% x 1.5 = around
32% oxygen.
So breathing around 32% oxygen at normal pressure should be equivalent to mild HBOT at 1.3 ATM with no supplemental oxygen.