Where should I start to approach the rebreather world

[Heat Miser]

If you are OK with diving a non-fully functioning unit...

You can run an e/hccr revo with 3 cells and it will still fully function. The extra 2 cells attached to the dreams are independant redundancy, they don't control the solenoid nor are they used by shearwater to determine pp02 or deco obligation.

You can also run a e/hccr revo on 1 dream and 5 cells fully functionally, so the extra dream is redundancy as well.

or in theory you can run two cells on one dream and another two cells on the other dream and run the CCR manually, monitoring 4 cells on the dreams.

very very good redundancy...

just don't take the open loop out of your mouth

 

[lermontov]

@Wibble
If you have Shearwater electronics, you can't do override the voting logic and that is very scary to me and people have died because of it. This alone is a HUGE benefit of the Divesoft electronics platform. If you have a cell fail that is on the solenoid side with a Shearwater controller you really need to call the dive.

maybe - you still have 2 cells on your nerd to cross check your PO2 on the controller

 

[lermontov]

It's not like I'll throw out my entire scrubber after one dive unless it's a pretty long/deep/cold one.
Easily do two 50-60m dives with 40-50 min bottom time on a fill of sorb, can you do that on the Revo and only use up one of your two scrubbers?
Because if not, then you are definitely not "saving a fortune" on sorb.

Or to phrase it another way, would you feel comfortable doing the two dives I mentioned above with just one of your scrubbers packed with sorb?
No, you wouldn't because you would most likely have a very bad time somewhere during dive #2.

If it's in one or two scrubbers should not make much of a difference, X kilos of sorb can absorb Y amount of co2, no?

if your going to to do 2x 50-60 m dive with 40-50 min of bottom time then youll be starting with fresh sorb yes? ive attached the Revo info sheet fro sorb changes- depending on depth and water temp you can get 2-3 hours from a canister

 

[broncobowsher]

If you do a 90 minute warm up dive today. Tomorrow you are planning on a 3+ hour dive.
rEvo, you dump one can after day one and have 2 good cans for the long dive.
Other rebreathers, you are dumping the barely used can to have a fresh full can for the long dive.

That is where you save on sorb. Either you are limiting the second dive on a canister of sorb or you are tossing good sorb to have a fresh canister to use it in one shot.

On light dives you are not chasing the tail end of life out of a canister of sorb to save money.

 

[Degenerate]

if your going to to do 2x 50-60 m dive with 40-50 min of bottom time then youll be starting with fresh sorb yes? ive attached the Revo info sheet fro sorb changes- depending on depth and water temp you can get 2-3 hours from a canister

I never doubted that you can do that on a full load of sorb.

The claim was that the dual scrubber system of the Revo would save you a ton of money on sorb because you typically only replace the sorb in one canister at the time.

I said that is bollocks because it is.
If you do a fresh fill of sorb in a Revo and do two 50-60m dives 40-50 mins of bottom time, would you throw out all out all of your sorb after that or would you keep the sorb in your secondary scrubber for your next (similar profile) dive?

If the second option is your go to then you are a lot braver than I am, sorb is hardly expensive and honestly its a really cheap life insurance.
If the first option is your go to then there is zero cost savings on sorb compared to a single scrubber CCR.

There is also a point to be made that two smaller scrubbers will be more affected by cold temps compared to a single large scrubber.

Thanks for the link btw, interesting reading for a european dude who is unlikely to ever encounter a Revo up north here.

@broncobowsher that actually makes sense.
Our dives are typically very similar in profiles so our savings would be zero.
Still think it's a stretch to say that you will "save a ton on sorb", but your point makes sense.

 

[rjack321]

You may save "a ton of money on sorb" and *only* replace 0.65 extra cells per year on a Revo... Alas, all of those savings will be wiped out when it has to go in for obscenely overpriced factory service to replace the counterlungs.

 

[Wibble]

Revo canister recycling…

Typically I do 2h dives and generally one dive a day. I generally just dump the top scrubber even if the RMS (monitoring system) says there’s still three hours left. For 1.3kg/3pounds of lime it’s simply not worth the hassle not to.

Occasionally, if there’s two consecutive days on the same boat, I may opt to not change the scrubber. Even after another dive the RMS has always indicated that there’s still plenty of time before the second scrubber's used.

I’ve heard of some people running their Revo’s scrubber for a lot longer than I do.

TBH 1.3kg of lime isn’t a massive amount to replace. If the canister took double or more than that, I’d be ripping through the tubs of sorb far faster than I do. Think I did 100 hours last year and used just over two large tubs.

 

[Heat Miser]

You may save "a ton of money on sorb" and *only* replace 0.65 extra cells per year on a Revo... Alas, all of those savings will be wiped out when it has to go in for obscenely overpriced factory service to replace the counterlungs.

Your such a sceptic, we haven't even started about the RMS nor the ability to easily replace/relube o-ring's. Or the aesthetically beautiful yellow and black jelly bean lid.

 

[rjack321]

Your such a sceptic, we haven't even started about the RMS nor the ability to easily replace/relube o-ring's. Or the aesthetically beautiful yellow and black jelly bean lid.

Please continue on the eternal wellspring of cost savings that is the Revo ^.^

 

[rddvet]

Revo... blech. Enough said