dave t

Yes well maybe three lungs would be better from a dwell time point but then WOB would be much higher, I guess its a compromise!

Its only a guess as I only got a quick look but I would say an inch to an inch and a half. The best direction is debatable, if you look at the test results of the classic kiss the exhale gas goes down a centre tube thus warming the sorb from the inside out (there is no outer gap on the kiss) and this appears to work very well. What one would think works very well is the exhale gas surrounding the sorb before being drawn into the actual pack. Kevin has proved this works on the sentinal but the inspiration is of the same design all be it a smaller gap and that didnt work quite so well. At the moment I am not decided on which way is best.

the tee's should sit almost on the top of your shoulder but just a little to the back, when you are in the swimming position or the upright position the tees will be almost level with your mouth and balance the hydrostatic effect. Any backmounted lung(s) should be adjustable to suit the individuals body shape and size

Dave