Hi Jorge;
We're talking apples vs. oranges. If you are going to use a scrubber, I agree that oxygen consumption is low compared to air consumption without a scrubber.
However, in the absence of a scrubber, ventilation requirements are 2 scfm of air per person at rest and 4 scfm of air per person not at rest (NOAA Diving Manual.) The flow rate is dependent on the number of occupants, not on the cabin volume.
The Sport Sub does not use a scrubber.
Stan
In a message dated 11/4/2003 6:41:11 AM Eastern Standard Time, jorloujr@uol.com.br writes:
I can not agree that continous flow leads to high air consumption. I don't know how acquainted you are with rebreathers, but it's the same principle the semi-closed circuit ones take advantage of: replacing just the amount of breathing mixture (I'm talking air here) that had it's oxygen content consumed. If a CO2 scrubber is to be used, it means that you can bring it (air consumptiom) to - roughly - 20% of what it would be when breathing from a regular scuba gear, giving you about 5 times more diving time. Besides that, without a CO2 scrubber, you can set the continous flow to be the same average consumption you would have with the regular gear (it can be lower depending on bottom time). For no reason, as far as I know, it should be higher.