Quote: (Originally Posted by
depth)
Hi
Since I almost entirely dive cold Scandinavian waters, I have a question regarding the scrubber.
I am currently using a meg, here the scrubber is a seperate unit from the can. This means that there is air between the aluminium can and the scrubber plexi glas. This isolates the scrubber from the cold aluminium can.
I know that heat is an important factor for the scrubber duration. The Peagian does not have this feature. Does this mean that the scrubber duration is effected to a larger degree when diving in cold water?
I like the thought of a smaller Rebreather, but not if it effects scrubber time considerably!
/Christian
I don't think that the Pelagian is more sensitive to cold water temperatures than the Meg.
First, the Pelagian scrubber has a thick plastic outer casing that has better heat insulation properties than the aluminium can of the Meg. We all know how great aluminium is to conduct heat :-)
I think that this somewhat makes upp for the fact that the scrubber chemicals of the Pelagian is only separated from the outside cold water by a single layer of material.
Second, Isn't the Pelagian internal scrubber diameter somewhat narrower than the Meg's? If so, wouldn't this leed to a somewhat more compact and hotter reaction zone, that would be less prone to heat loss and temperature drop due to cold ambient conditions, than a cooler "burning" larger diameter scrubber like the one in the Meg?
Third, the unit packs a big standard scrubber with a capacity of 3,4 kg of Sofnolime 797. This gives the cold water diver an added extra margin of saftey.
Fourth, The compact design of the Pelagian has less surface area that can be exposed to the cold enviroment than other rebreathers. Especially the breathing hoses are quite short and compact, reducing the risk of loss of heat to the surrounding enviroment. The CL are also wery well protected and insulated from the enviroment.
As of today, the Pelagian standard size scrubber, is rated to 6 hours in warm water and 4 hours in cold water. My own unit hasn't done enough hours in realy cold water to draw any conclusions yet...
After the end of this summer there will be a bunch more of Swedish and other cold water diving nationalities using the Pelagian, so then there will be more experience in ice cold waters with the Pelagian.
I'll gues Roger is the one to ask as he has a lot of experience on both units.
Btw the Pelagian is a sweet well balanced and very compact litle unit.
I'd like to think of it as the equivalent of a
Sports Bike in the rebreather market.
A big engine = large scrubber capacity
High acceleration = Low WOB
very high max speed = no depth limit
high maneuverability = excelent trim and balance
Well it's actually a bit more than words that conects the Pelagain to a Sports Bike. The internal bladder of the counter lungs are made of inner tubes from motorcycle tyres, very tough
/Johan Fredin