Let's say you have switched to your alternate air source which happens to be a common 2nd stage regulator octopus or one of the new alternate air source systems built into the power inflater of a buoyancy compensator. If you have enough air to last, at your normal rate of breathing, 10 minutes, that same amount of air can last 12 minutes if you were using an Air Buddy.
Would that extra 2 minutes be useful? Maybe you wouldn't need it. Maybe it would make the difference between surviving or not.
How does the Air Buddy do this?
You need to know a few facts to understand how this happens.
When breathing from a normal regulator 2nd stage, the first air that goes into the lungs is the stale air that is located in your tracheal and oral cavities as well as the chamber of your second stage. This air is poor in oxygen because you have just exhaled it.
Exhaustive testing in hospitals has proven that the best way to keep oxygen levels up and Co2 levels down is to deliver the gas to the patient in a the form of a puff bolus rather than on simple demand.
1. The trigger that signals your body to take a breath is the amount of carbon dioxide in your blood.
When your blood carbon dioxide level reaches a certain level, your body takes a breath. You don't have anything to do with it.
2. When you exhale, the air that remains in the space from the opening to your lungs up through your throat and mouth and including the air in your regulator second stage pressure chamber is high in carbon dioxide.
3. When you take your next breath, you suck air through your regulator and the first air that goes into your lungs is that exhaled stale air that is already high in carbon dioxide.
The Air Buddy doesn't work that way.
1. You don't suck to get air from an Air Buddy. You squeeze the mouthpiece and the Air Buddy blows the air into your mouth.
2. The air that is blown in is fresh air, with no carbon dioxide. There is also almost no stale air in the Air Buddy itself because it is so tiny. That fresh air creates a turbulence, mixing whatever stale air you have retained, reducing the percentage of carbon dioxide. So the air that you are inhaling into your lungs has less carbon dioxide than what you would get from any other alternate air source system. This is the same type of system used to give breathing air to premature babies in the hosptal for their well being.
3. So, each breath you take with an Air Buddy has less carbon dioxide in it, causing your body to wait for a longer period of time before your carbon dioxide level builds to a point where it triggers your breathing response.
4. The net result is that your body will automatically take only 4 breaths using an Air Buddy during the same time period it would be taking 5 breaths with any other current system.
5. This difference in breathing is controlled by your autonomic nervous system and is not even noticed by you that it is happening.
It's one more safety factor to have on your side.