Oxygen Usage

**Steve** · 25th January 2006, 05:48

Disregarding actual metabolic oxygen consumption and focusing on actual gas used; how many litres of O2 do you guys use per minute?

ROB DAVIE · 25th January 2006, 05:52

Steve,

I have found the average of one free litre per minute quite acceptable.

Rob

decoweenie · 25th January 2006, 07:29

Quote: (Originally Posted by ROB DAVIE)

I have found the average of one free litre per minute quite acceptable.

Rob,

If you track the actual O2 used per dive versus the minutes dived, I am sure you will find the amount to be more than 1 LPM. In general, I found that 1 LPM is more-or-less the metabolic rate of an active diver with normal finning. Slightly less on deco. More for swimming against current.

When account for wastage, the value will add up.

I did this for the first 1000 minutes of diving CCR a long time ago, and it was around 2 LPM due to wastage/ascent/etc.

Of course, the actual value will depend on your dive profile (more sawtooth ?), depth (more ascent wastage), deco (more flushing), etc.

I no longer track this usage since I found that it didn't fluctuate much for my diving, so using 2 LPM to plan for the dive trip eversince.

Just based on what I see...

koputai · 25th January 2006, 07:43

Steve,
Around 1.4 LPM.

Jason.

Nick uk. · 25th January 2006, 07:55

I must admit i don't know precisely, how much i 'metabolize' but on 70' dive i'm using about 50 bar, and doing some O2 flushes.

**nigelh** · 25th January 2006, 09:08

Looking through my logs...
Deco diving it is normally under 1L/min averaged over the whole dive including what bubbles off on the ascent. Shallower stuff comes out a bit higher. I'm not sure why. Perhaps I am less careful.

Andy Del · 25th January 2006, 09:47

I've found about 2 litres per minute based on 50m dives for around 70 minutes. This includes flushes, is my bailout O2 reg working tests and the like.

robvdmr13 · 25th January 2006, 11:26

Including flushes and all I use 15 bar every half hour (3 litre tank), so 1.5 lpm. It`s a bit lower when I go deeper, but can easily reach 2 lpm in the shallows (This is often due to OC buddy`s who don`t seem to understand why I ask them to try to minimize sawtooth profiles.

)

Robert

ROB DAVIE · 25th January 2006, 16:24

Quote: (Originally Posted by decoweenie)

Rob,

If you track the actual O2 used per dive versus the minutes dived, I am sure you will find the amount to be more than 1 LPM. In general, I found that 1 LPM is more-or-less the metabolic rate of an active diver with normal finning. Slightly less on deco. More for swimming against current.

When account for wastage, the value will add up.

I did this for the first 1000 minutes of diving CCR a long time ago, and it was around 2 LPM due to wastage/ascent/etc.

Of course, the actual value will depend on your dive profile (more sawtooth ?), depth (more ascent wastage), deco (more flushing), etc.

I no longer track this usage since I found that it didn't fluctuate much for my diving, so using 2 LPM to plan for the dive trip eversince.

Just based on what I see...

Phi,

It was late last night, and I was helping Steve edit his poll. It looks as if I was thinking of the metabolic rate, rather than the average useage.

You are spot on as usual. The figure of 2 litres per minute is indeed a good "real world" average for planning purposes. Thanks!

Rob

divetheworld · 25th January 2006, 18:58

1.5 usage average usage over a dive for me.
My buddy doesnt seem to metabolise hardly any oxygen, the get always ends up with more left than me. I dont think he's human. I set up my old Dolphin on him and it ended up 0.6L/min on the valve after an hour in the wet stuff.

I guess I'll just have to face it, drinking Newcy brown, being a fat tw@t and bar fighting is not the healthy option.

View Poll Results: How many litres of O2 per minute do you use?
1.0 lpm or less	33	46.48%
1.25 lpm	10	14.08%
1.5 lpm	14	19.72%
1.75 lpm	5	7.04%
2.0 lpm	7	9.86%
2.25 lpm or more	2	2.82%
Voters: 71. You may not vote on this poll

25th January 2006, 05:48	#1 (permalink)
Steve Ladies bring a plate Current Rebreather/s: Megalodon Home Build Other Rebreather/s: Not Bought Yet Inspiration Classic Sport Kiss Classic Kiss MK 15.X Home Build Join Date: Feb 2005 Location: Perth - Australia Posts: 1,068	Oxygen Usage Disregarding actual metabolic oxygen consumption and focusing on actual gas used; how many litres of O2 do you guys use per minute? __________________ WARNING: I contain occasional coarse language, extreme sexual references, nudity, and adult themes, which may offend some people - Usually churchy types.
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25th January 2006, 05:52	#2 (permalink)
ROB DAVIE Administrator Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: HOUSTON, REPUBLIC OF TEJAS Posts: 1,120	Re: Oxygen Usage Steve, I have found the average of one free litre per minute quite acceptable. Rob
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25th January 2006, 07:29	#3 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,510	Re: Oxygen Usage Quote: (Originally Posted by ROB DAVIE) I have found the average of one free litre per minute quite acceptable. Rob, If you track the actual O2 used per dive versus the minutes dived, I am sure you will find the amount to be more than 1 LPM. In general, I found that 1 LPM is more-or-less the metabolic rate of an active diver with normal finning. Slightly less on deco. More for swimming against current. When account for wastage, the value will add up. I did this for the first 1000 minutes of diving CCR a long time ago, and it was around 2 LPM due to wastage/ascent/etc. Of course, the actual value will depend on your dive profile (more sawtooth ?), depth (more ascent wastage), deco (more flushing), etc. I no longer track this usage since I found that it didn't fluctuate much for my diving, so using 2 LPM to plan for the dive trip eversince. Just based on what I see... __________________ "...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..." - Rebreather World PM Last edited by decoweenie : 25th January 2006 at 08:23.
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25th January 2006, 07:43	#4 (permalink)
koputai Subsea Systems Current Rebreather/s: MK 15.X Other CCR Other SCR Other Rebreather/s: Not Bought Yet Other CCR Other SCR Join Date: Jul 2005 Location: Sydney, Australia Posts: 308	Re: Oxygen Usage Steve, Around 1.4 LPM. Jason.
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25th January 2006, 07:55	#5 (permalink)
Nick uk. Made in England. Current Rebreather/s: Inspiration Classic Azimuth Other Rebreather/s: Azimuth Join Date: Nov 2005 Location: Viale C.Colombo 75 Marina di Carrara. MS 54036 Italy Posts: 579	Re: Oxygen Usage I must admit i don't know precisely, how much i 'metabolize' but on 70' dive i'm using about 50 bar, and doing some O2 flushes. __________________ If it aint broke....don't fix it, and if it is.............well......get another one! divechief2000@hotmail.com
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25th January 2006, 09:08	#6 (permalink)
nigelh New Member Current Rebreather/s: Inspiration Vision Other CCR Other Rebreather/s: Inspiration Classic Other CCR Join Date: Mar 2005 Location: Brighton, Sussex, UK Posts: 792	Re: Oxygen Usage Looking through my logs... Deco diving it is normally under 1L/min averaged over the whole dive including what bubbles off on the ascent. Shallower stuff comes out a bit higher. I'm not sure why. Perhaps I am less careful. __________________ nigelh
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25th January 2006, 09:47	#7 (permalink)
Andy Del Classic KISSer Current Rebreather/s: Sport Kiss Classic Kiss Other Rebreather/s: Join Date: Feb 2005 Location: Australia, Sunny Sydney Posts: 391	Re: Oxygen Usage I've found about 2 litres per minute based on 50m dives for around 70 minutes. This includes flushes, is my bailout O2 reg working tests and the like. __________________ Yellow - the colour of greatness!
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25th January 2006, 11:26	#8 (permalink)
robvdmr13 New Member Current Rebreather/s: Inspiration Classic Dolphin Other Rebreather/s: Dolphin Join Date: Jan 2006 Location: The Netherlands Posts: 44	Re: Oxygen Usage Including flushes and all I use 15 bar every half hour (3 litre tank), so 1.5 lpm. It`s a bit lower when I go deeper, but can easily reach 2 lpm in the shallows (This is often due to OC buddy`s who don`t seem to understand why I ask them to try to minimize sawtooth profiles.) Robert
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25th January 2006, 16:24	#9 (permalink)
ROB DAVIE Administrator Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: HOUSTON, REPUBLIC OF TEJAS Posts: 1,120	Re: Oxygen Usage Quote: (Originally Posted by decoweenie) Rob, If you track the actual O2 used per dive versus the minutes dived, I am sure you will find the amount to be more than 1 LPM. In general, I found that 1 LPM is more-or-less the metabolic rate of an active diver with normal finning. Slightly less on deco. More for swimming against current. When account for wastage, the value will add up. I did this for the first 1000 minutes of diving CCR a long time ago, and it was around 2 LPM due to wastage/ascent/etc. Of course, the actual value will depend on your dive profile (more sawtooth ?), depth (more ascent wastage), deco (more flushing), etc. I no longer track this usage since I found that it didn't fluctuate much for my diving, so using 2 LPM to plan for the dive trip eversince. Just based on what I see... Phi, It was late last night, and I was helping Steve edit his poll. It looks as if I was thinking of the metabolic rate, rather than the average useage. You are spot on as usual. The figure of 2 litres per minute is indeed a good "real world" average for planning purposes. Thanks! Rob
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25th January 2006, 18:58	#10 (permalink)
divetheworld Dive porn pimp Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Inspiration Vision Classic Kiss Other CCR Join Date: Mar 2005 Location: Leeds, England Posts: 1,535	Re: Oxygen Usage 1.5 usage average usage over a dive for me. My buddy doesnt seem to metabolise hardly any oxygen, the get always ends up with more left than me. I dont think he's human. I set up my old Dolphin on him and it ended up 0.6L/min on the valve after an hour in the wet stuff. I guess I'll just have to face it, drinking Newcy brown, being a fat tw@t and bar fighting is not the healthy option. __________________ Self praise is no reccomendation. Dont try to be a great man, just be a man and let history be the judge of you. CHECK OUT OUR INTERWEBS FOR CUSTOM REBREATHER UPGRADES *WWW.NARKEDAT90.CO.UK* *http://www.grpservices.com/pursuit/* Supporting Shearwater Research Products in Europe
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