Types of Rebreathers Introduction
Rebreathers are diving systems that recycle your breathing gas. This drastically extends the supply of breathing gas by reusing exhaled gas. There are two types of rebreathers on the market today: closed-circuit rebreathers and semi-closed circuit rebreathers. All rebreathers are similar in design and have several of the same components. Every rebreather must incorporate a variable volume container that is responsible for capturing your exhaled breathing gas. This is typically what is known as a breathing bag or counterlung.
Another shared component of all rebreathers is a scrubber. A scrubber is a device that is responsible for removing the expired carbon dioxide from the breathing gas as it passes through the system. Scrubbers today typically use sodalime, which is a disposable chemical carbon dioxide absorbent.
The counterlung and scrubber make up the breathing loop, which is the path taken by the breathing gas. Other pieces of a rebreather make up the entire breathing loop and include the mouthpiece and breather hoses. Your lungs are also considered part of the breathing loop because they contain the gas during a portion of the recycling process.
The two types of rebreathers, closed-circuit and semi-closed circuit, can be broken into three different types of rebreathers: oxygen closed-circuit rebreathers, semi-closed circuit rebreathers, and mixed-gas closed-circuit rebreathers.