View Full Version : Venturi Switch and SAC

08-29-2007, 08:50
Does opening the venturi switch to max airflow really change how much air you consume?

No Misses
08-29-2007, 08:57
This is just a guess...
If you are not working hard to breath, you should use less O2 (convert to CO2). It is the buildup of CO2 that makes you want to breath. You should use less gas.

08-29-2007, 09:43
I do not know for sure but if No Misses is correct then I think that it would be minimal at best.

Hopefully someone with a little more knowledge will pipe up. I would be interested to hear their answer...


08-29-2007, 13:09
maybe if you are using less power to get the air, then a bit... i suppose.

Capt Hook
08-29-2007, 15:04
Interesting question! If I don't switch mine I really don't notice much difference in breathing effort until I get to 70+ ft. Never thought about whether it is costing me air or not, hmm.

08-29-2007, 20:42
it maybe just a mind thing but it does seem like I used less air when the switch is less

08-29-2007, 20:48
I can't imagine that it would make much difference unless the difficulty increased anxiety.

fire diver
08-29-2007, 21:01
The venturi works by deflecting some of the airflow against the front diaphram. This helps stop the airflow during VERY high flow volumes such as free-flow. On normal breathing, I don't notice a difference. But your reg and breathing may vary.