Optima and granular sorb

[paulraymaekers]

By weight, the EAC absorbs more CO2 than does the same amount of granular.

Sorry to intefere here, Howard, but the above statement is simply untrue!

from all the test we have run, at whatever temperature and whatever CO2 flowrate, most fine grain sorbs absorb more CO2 per weight then EAC's.

I do agree that EAC's can have advantages in easier packing, but outside the US the availability at correct price is clearly a problem. And taking EAC's with you when traveling is certainly more risky to damage them, than taking granular sorb with you


paul

 

[Gill Envy]

Thanks for the thoughtful reply Howard and sorry for the slow response.

You bring up an interesting perspective which I think is common in the CCR world and I think it has an important flaw. I do hear on occasion attitudes like "hey, if you are diving CCR then you are not worried about price, just suck it up". This comes up in all kinds of ways like $20 o2 fills for $3 worth of O2, $50 dollar Bull Nose fittings that cost $18 at the local compressed gas dealer, $150 for a keg of safno when the same amount of sodasorb can be had for $75. The world of CCR is still small niche enough that it can get away with this kind of price gauging but I think those days are numbered as the mainstream gets more involved. Personally, I think continuing to assume CCR divers are careless about their spending habits is a poor marketing approach.

I do think it's important to realize that a lot of folks are getting into CCR who are not super rich but instead are making a very calculated choice about what they will be getting for their hard earned cash, many are going straight from OC recreational to CCR and do not have the comparison of expensive OC HE fills to help ease the pain. You don't hear the word "Frugality" and rebreathers in the same sentence very often but I do think there are quite a few of us that are careful spenders and perhaps because of that have the cash to spend on CCR diving. Frugality is a good thing, IMHO, regardless of how much one has in the bank.

So far my use of granular sorb, both sodasorb and safno, have not turned up an appreciable "risk" as you mention, over EAC's and the improved WOB of the EAC can be had through a radial version of a granular scrubber, which also has the side benefit of improving economy of sorb even more. I think trying to scare the public about the "risks" of granular sorb is marketing hype and I think EAC's are way overpriced for what they have to offer... people have been saying for years that the price will come down as they grow in popularity and I have yet to see that. Then there is the issue of flexibility, choosing a rig that can not take granular and canister, such a rig has a big disadvantage in my book if it's limited to the micro niche of EAC's, at least if you plan to dive in remote locations like the south pacific.

You know I like the Optima in many respects, and you know I can see advantages to the EAC as an option, and I'd really like to see the day when the Optima is available with a granular option, I'd even point people to it with "optima-ism" ;~).

I do have to say though, the day I make it out to "God's Junkyard" in Lembeh and see one of those canisters rolling around the ocean floor because the natives use the tide as their trash removal service will be a sad day. I hope they use something bio-degradable for substrate in the future because those canisters will not always get disposed of properly.

Kind Regards,
g

There are people buying in bulk. However, even assuming that you are paying the retail price, an EAC is rated to scrub 240 liters of carbon dioxide. Assuming production of one liter per minute, that comes to 240 minutes, or four hours. Even at $40 per EAC, that comes to ten dollars per hour.

Anyone who is spending the money that it takes to get a rebreather in the first place is likely to be able to spend $10 per hour for scrubber. So, if you are only spending half of this but are risking things like caustic dust from sorb powder that makes its way to your mouth, I am willing to pay a few bucks more to eliminate this risk.

Second, if you are changing from open circuit diving, where you were paying sometimes more than $125 in Trimix for filling a set of doubles for a single dive, and you are now paying perhaps $30 for about four dives worth of Trimix and oxygen in your CCR tanks, I am not going to be overly concerned about paying an extra $5 per hour for operating cost. My primary concern lies elsewhere such as ease of use, tolerance to water contact, and low work of breathing.

:depressed: