Suggested CCR Reading

[rjack321]

Well, then the JJ will be great, because that brings more of the shoulder portion lower. If you keep your counterlungs slightly fuller, breathing is almost effortless. And cells will stay at the top of the tube (but they're well engineered anyway re: position).
On your back, for example, you can see that sensor #2 will then face uppermost, and you can see on your handset which cell suddenly changes its reading if it's face is flooded. The other two cells remain sideways to condensate, even on your back.
View attachment 612318
In contrast, the Meg head has the cells facing down, which means up when you're inverted. The Meg guys can say whether that's a risk for trapping water when inverted. On your back shouldn't affect things.
View attachment 612319

Just don't lay the unit down on its back after the dive

 

[KenGordon]

Just don't lay the unit down on its back after the dive

You’d have to try very hard to have enough condensation for that to be an issue.

 

[rjack321]

You’d have to try very hard to have enough condensation for that to be an issue.

All i know is the every JJ diver I dive with is religious about keeping it upright

 

[KenGordon]

All i know is the every JJ diver I dive with is religious about keeping it upright

Never been a problem for me. I lay mine down in the car. Obviously it is upright on the boat etc. Most of the condensation ends up on the other side of the scrubber.

 

[rsingler]

All i know is the every JJ diver I dive with is religious about keeping it upright

You could have a full cup of water in the can, and it wouldn't touch the sorb upright. Lying on its side, you could soak it. But then, all that water would have to get past the T-piece. If your counterlungs don't have more that the usual saliva, then it won't matter what position you lay it in, unless it's been a really long dive. I find about a tablespoon in the can.

 

[rjack321]

You could have a full cup of water in the can, and it wouldn't touch the sorb upright. Lying on its side, you could soak it. But then, all that water would have to get past the T-piece. If your counterlungs don't have more that the usual saliva, then it won't matter what position you lay it in, unless it's been a really long dive. I find about a tablespoon in the can.

no its not about the sorb, its about condensation on the walls of the can running back down and ending up on cell2 (supposedly)

 

[KenGordon]

no its not about the sorb, its about condensation on the walls of the can running back down and ending up on cell2 (supposedly)

Condensation on the metal part of the can would have to get past the sorb. Only condensation from one of the loop tubes and the head around the cells can reach the cells. That is the inhale side, so the gas has already been down a cold loop, into a cold can and been sucked through a warm scrubber. It does end up wet, but not swimming like the can.

 

[rsingler]

That's what I meant about a long dive. Condensation, as opposed to flooding.

And maybe we're splitting hairs here, but the walls are outside the scrubber. It would have to be condensate accumulating in the center tube of the head area. But laid on its side, that area drains right into the pocket below the head, while cell #2 sticks up about 1/8" into the tube. It could happen, but I don't worry about it.
JJ Divers don't lay them on their backs so they don't scratch the pretty anodizing.

Ah! I see that Ken beat me to it!

 

[rjack321]

Condensation on the metal part of the can would have to get past the sorb. Only condensation from one of the loop tubes and the head around the cells can reach the cells. That is the inhale side, so the gas has already been down a cold loop, into a cold can and been sucked through a warm scrubber. It does end up wet, but not swimming like the can.

I dont really know, but multiple JJ divers here from multiple MOD1 instructors are "worried" about post dive condensation getting on the cells and transport their units home upright.
Ps the inhale gas is 100% RH too, the entire loop has condensation in cold water - our water is about 7-12C depending on the site and time of year

 

[Jack Hammer]

the inhale gas is 100% RH too, the entire loop has condensation in cold water - our water is about 7-12C depending on the site and time of year

I dive Great Lakes (cold, 4-8c) and get quite a bit of condensation on the inhale loop and the head area. We were taught to remove the head so it can dry after the dive. Condensation is possible on the cell but not likely. Even inverted it would take a lot more condensation than I've yet to see to cause any issues, though it's not impossible. A flooded can would be more of an issue if inverting.

I stand it up for travel because it's less work and it has a nice stable stand. Laying it down it wobbles side to side.