[PSUBS-MAILIST] scrubber performance

[Sean T. Stevenson via Personal_Submersibles]

I don't recall seeing insulation in the DW2000 either.  Perhaps Phil
will chime in on this?  It is possible that being so compact, the
surface area of the DW hull is small enough that the contained heat
loads can keep up to the moisture production.  Also, those are certified
through GL, and as such may have different requirements than ABS's 30% -
70% RH.  Can anyone speak to the GL rules on this?  I can't see avoiding
a 100 % RH environment, and the consequent condensation, when submerged
in 5°C water without either insulating or employing dessicants to remove
the moisture.  Immediately next to the hull, it will always be colder,
so you may get condensation on the hull despite being within humidity
limits on the cabin air on average.  I was thinking that a cylindrical
pressure hull would be relatively simple to insulate though, with
something like AP Armaflex sheet material.  You wouldn't even
necessarily need to apply at 100% coverage, but rather just enough to
reduce the heat loss to meet the 70% RH limit at whatever your cabin
temperature is. (14°C - 30°C are the recommended temperature limits, but
that's not actually a rule under ABS UWVS). Insulating just the large
cylindrical surfaces between frames might be sufficient.  In my own
design, insulation is a necessity - otherwise I won't be able to keep my
coffee hot.

Sean


On 2017-02-15 17:41, hank pronk via Personal_Submersibles wrote:
> Sean,
> I can not remember the temperature over the length of a typical dive.
>  I would estimate 10C after 1\2 hr at 100 feet.   When I dive Kootenay
>  lake it is probably 5C 
> I wonder how DW's manage, they dive all over the world and I am sure
> in the winter.
> Hank

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