On 01/01/2021 11:14, GB wrote:
On 31/12/2020 18:53, nightjar wrote:

The amount of oxygen they take from the air is fairly small, but, if
you are in the same room as the compressor and don't have a window
cracked open, it can feel a bit stuffy after a few hours.


This doesn't make sense to me, I'm afraid. The amount of oxygen being
used up in the room is the amount being converted into CO2 by the
patient. The oxygen concentrator won't alter that significantly.

What's happening is that oxygen enriched air is being fed into the
patient's lungs. The patient absorbs some of that oxygen, and the excess
gets expelled back into the room, where it mixes with the remaining air.


Whether it makes sense to you or not, that is my experience of using
one. I get the same thing with the concentrator in my car. If I forget
to crack open a window, after a while it reminds me of its presence by
making the air feel heavy.

--
Colin Bignell