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WOB isn’t an issue for professionally engineered commercial, military or recreational rebreathers.
no effect on gas velocity. Think about it, your lungs are moving gas at some rate based on your inhale/exhale cycle so the velocity of the gas is determined by your lungs. What does happen is what I had mentioned above where in a split lung design ~1/2 of the gas goes through the scrubber on the exhale cycle *being pushed through* and the other half goes through on the inhale cycle *being pulled through*. This means the scrubber is being used for half as long, but twice as often. This doubles dwell time for the gas that is in the scrubber during the "pause" between inhale/exhale cycles if you ever actually take a pause in your breathing cycle. Now because most people inhale and exhale at different speeds, half of that lung volume will be going through the scrubber at a different rate than the other which COULD increase dwell time, but it depends on if your inhale cycle is faster or slower and where the single counterlung is in the loop *most single lung units are on the exhale side, but the Sidewinder is in the middle and is a weird one because of that*. So if you have a really fast inhale and a really slow exhale then the dual lungs would conceivably have more dwell time at least on the exhale cycle and you get whatever gas is "paused" inside the scrubber which on a radial with a massive reaction front probably helps a little bit, but we are definitely in splitting hairs territory. Dual lungs work on most units because it's convenient, don't discount a single lung scrubber JUST because it is a single lung and automatically assume all dual lungs are going to be more efficient.
