Quote: (Originally Posted by mverick)
You have 2 heat sources. The person breathing and the scrubber. Scrubber being hotter.
Be intresting to test loop temps.
The plastic will get up to temp. Whatever the loop temp is plus some. On metal it will quicker. Because it holds the scubber material it has direct contact.
Don't have to heat up metal to a higher temp. And, the scrubber is Hot. Without question. That's why all the condensation on the bucket. But, between the bucket and the scrubber you have an airspace. Which is a great insulator. Thing taking heat away is the air flow through the scrubber. Which is heated through the scrubber.
In to out will be more efficient. Because your not pulling the exhale heat out on the bucket wall before scrubber. I just don't think the scrubber material matters. Out to in you pull moisture out. Then run it through the heated scrubber where it heats back up so it will not condense as easy. Which would be why not noticeable on the cells. You're re heating the air. You do loose some scrubber efficiency though.
You want to loose heat in a rebreather but not loose it in the scrubber. Just want to do it where you want. Otherwise, It would be cooking you from the
inside out.
mverick, my undersanding of thermodynamics, very limited as it is, is that it's not just the temp differential and conductivity that are taken itnto account, it's also the density and mass of the things transfering the heat. The CCR loop gas is much less dense and there's much less of it than the water surounding it, which would constantly draw the heat away from the loop. The plastic makes this happen more slowly in colder water. And an in to out flow further minimizes this.
As for condesation, the Meg sensors are mounted in the plenum, which directly contacts the outside/water, right? And the first point of condensation is here, right? I think I'd rather have my first point of condensation occur on the scrubber wall-in to out-before it hits the sensors, ala Prism. It sounds like the 1 way drain in the older Megs might have been a good idea, although less simple than a moisture pad... -Andy