Would like a high level overview of CCR costs, weights, and packability for travel.

[PfcAJ]

modern ones yes. You can go lighter if you get a Walter Kidde, but not much. Keep in mind you will always have to keep a keg of sorb with you that is 45lbs.

We'll call a backplate/wing a wash since you need it for either kit

2al80's plus compressor is 180lbs ish.

The SF2 is one of the lighter units out there and it is 40lbs empty, plus a 44lb keg, plus 20lbs for 1 set of onboard tanks, plus at least 1 al80 for bailout at 40lbs, so it's about a wash for weight but with the compressor you never have to go into a dive shop for fills if you don't want to. The CCR you have to find a shop with pure O2, and ideally high pressure O2, and that isn't always easy or even possible depending on where you are in the country. Now you can always use any CCR as an SCR with a rich diluent mix, but it's not exactly the most recommended thing in the world since it makes hypoxia quite high as a risk since you have to remember to exhale, the unit won't for you.

Not trying to talk you out of CCR, but if the goal is traveling around the country out of a vehicle of some sort, a portable compressor and a pair of tanks would be my choice on how to do that, and I own a rebreather...

I don’t think you need to travel with a full keg. One fill in the breather and one in a sealed container will probably last a whole trip.

 

[tbone1004]

I don’t think you need to travel with a full keg. One fill in the breather and one in a sealed container will probably last a whole trip.

but then you have to unpack it and I'm far too lazy for that

 

[KevinNM]

The SF2 is one of the lighter units out there and it is 40lbs empty, plus a 44lb keg, plus 20lbs for 1 set of onboard tanks, plus at least 1 al80 for bailout at 40lbs, so it's about a wash for weight but with the compressor you never have to go into a dive shop for fills if you don't want to. The CCR you have to find a shop with pure O2, and ideally high pressure O2, and that isn't always easy or even possible depending on where you are in the country.

Could you use the 90%-95% O2 that a decent oxygen concentrator produces as the fill for your O2 cylinder?

You'd need a haskel or something too, I guess.

 

[runsongas]

psa leaves too much argon without an additional filtration stack which adds cost and takes up more space. not really portable.

 

[KevinNM]

psa leaves too much argon without an additional filtration stack which adds cost and takes up more space. not really portable.

Yeah, I see what you mean, the 4% of Argon typical in 95% O2 from a concentrator might be a problem given that Argon is fairly narcotic. But only about 50-70% more than N2, so off the top of my head I don't see it as a huge deal for people who are not planning 80m+ dives. But I could well be wrong.

How would you filter out argon? The only way of producing it I know of involves multiple column cryo distillation (like a big 'Air Gas' or Praxair plant) due to it being totally non-reactive and having a boiling point only 2K less than Oxygen.

 

[runsongas]

builds up in the loop over time forcing flushes which starts putting you in scr vs ccr mode.

there are zeolites with oxygen vs argon selectivity that can be used.

 

[kensuf]

Before anyone thinks it may be a good idea, I want to mention that filling empty 2L soda bottles with sorb is stupid. The acid left in the bottle could potentially react with the sorb, reducing it's ability to function effectively.

 

[Exigent]

Not from fwc but fwc is linked from this site. Spearing | eRegulations it states no use of rebreathers in state waters in Florida for spearing.

Essentially the same information, but here it is on the FWC website for absolute certainty. Spearing

If you are after Lionfish, they are fair game while using a rebreather. 15266556, 68B-5.006 - Florida Administrative Rules, Law, Code, Register - FAC, FAR, eRulemaking

 

[joshk]

The SF2 is one of the lighter units out there and it is 40lbs empty

Empty being without tanks and sorb? It's lighter than that I think, I'd estimate 15-20lbs but I could be off.

Before anyone thinks it may be a good idea, I want to mention that filling empty 2L soda bottles with sorb is stupid. The acid left in the bottle could potentially react with the sorb, reducing it's ability to function effectively.

Was this idea pitched somewhere?

 

[tbone1004]

Could you use the 90%-95% O2 that a decent oxygen concentrator produces as the fill for your O2 cylinder?

You'd need a haskel or something too, I guess.

I have an invacare homefill in my garage that I use to PSA what we call "argox" and it compresses to 2200psi comfortably. Super slow, ~.05cfm, but it works. The military uses PSA all the time in remote locations, just have to dil flush to prevent argon buildup. Someone a while back ran the math and it's something like a dil flush every 15-20 minutes give or take.

@joshk just checked, the sidemount "ready to dive" is 30lbs, so the 40lbs must be the shipping weight that they quoted which sounds like it has the bp/w, regulators, etc.