Argon and Dry Suits -- How much warmer?

[b1gcountry]

Only slightly off topic: there was a recently study in the UK where doctors told their patients that they were prescribing a placebo, and for 17% of patients the placebo still worked.

I sort of assumed those 17% must come from Manchester, but the article didn't say.

On an unrelated note, 17% of the population don't know the difference between 'placebo' and 'panacea'.

 

[Rick Inman]

On an unrelated note, 17% of the population don't know the difference between 'placebo' and 'panacea'.

I know I didn't... so I went to Nereas .com and did a search and found:

Panacea: a remedy for all ills or difficulties : cure-all

Placebo: 1 a: a usually pharmacologically inert preparation prescribed more for the mental relief of the patient than for its actual effect on a disorder

 

[Gene_Hobbs]

Took us a while to get it done but IEEE has released several papers to us. I created the new IEEE collection tonight with the first three papers.

So... as promised...

Nuckols ML, Giblo J, Wood-Putnam JL. Thermal Characteristics of Diving Garments When Using Argon as a Suit Inflation Gas. Proceedings of the Oceans 08 MTS/IEEE Quebec, Canada Meeting September 15-18, 2008. RRR ID: 7962

figures 6 and 7 appear to be missing so we have requested a better copy from the author...


Rubicon is participating in the Great Human Race 5k Run/ Walk in Durham, NC, USA on March 21st. Please consider sponsoring our team. More info available here.

 

[Rick Inman]

From Gene's Link:

Improvements in localized thermal insulation values were seen throughout both drysuit ensembles when using argon as an inflation gas when compared with those while using air. Improvements with argon inflation in an experimental aerogel garment ranged from a low of 11% in the legs, 27% in the arms, and 22% in the torso. Overall, the total suit insulation increased with the aerogel garment by approximately 16%. Improvements with argon inflation in a commercial drysuit ranged from a low of 5% in the torso, 12% in the arms, to a high of 32% in the legs. Overall, the total suit insulation increased with the commercial garment by approximately 20%. This investigation demonstrated that significant improvements in drysuit thermal protection can be achieved when using argon instead of air as a drysuit inflation gas.

Thank you. End of story. All you placebo arguers were WRONG, so apologize now and humbly head down to your LDS to buy a small bottle and an argon reg.

 

[Randy43068]

Rick, after reading the above post I can only describe my posture:
Head down, hands in pockets, shoulders drooping, and I'm making lines in the dirt with my toe.

Shame on we naysayers!!

 

[dave4868]

From Gene's Link:

Improvements in localized thermal insulation values were seen throughout both drysuit ensembles when using argon as an inflation gas when compared with those while using air. Improvements with argon inflation in an experimental aerogel garment ranged from a low of 11% in the legs, 27% in the arms, and 22% in the torso. Overall, the total suit insulation increased with the aerogel garment by approximately 16%. Improvements with argon inflation in a commercial drysuit ranged from a low of 5% in the torso, 12% in the arms, to a high of 32% in the legs. Overall, the total suit insulation increased with the commercial garment by approximately 20%. This investigation demonstrated that significant improvements in drysuit thermal protection can be achieved when using argon instead of air as a drysuit inflation gas.

Thank you. End of story. All you placebo arguers were WRONG, so apologize now and humbly head down to your LDS to buy a small bottle and an argon reg.

No doubt about it: argon reduces heat transfer better than air!

Definitely not a placebo effect! Well, wait a minute now....At least not if the diver purged his suit at least 6 times to get that, roughly, 20% improvement.

Question: How many divers actually purge their suits at least 6 times with the argon? If they didn't purge 6 times, how much less improvement did they achieve? Did they still sense a significant improvement? Sounds like many still felt it was significant. Was it?

Actually, I never doubted that argon reduced heat transfer, just whether it's worth the trouble when other simpler methods may work better, such as using more insulation, using more air in the suit, avoiding constriction, etc.

I'd love to see a study of the thermal effects of simply using more air in the drysuit, of air that stays drier when purged more often during the course of the dive, which often happens as a consequence of having more air in the suit, and of simply increasing insulation in areas of high heat transfer.

I'm going to guess the improvement might be greater than 20%....it sure feels like it! And I know it's not a placebo effect!

Of course, there are drawbacks to using more air in the suit. Simplicity isn't one of them, though....

Dave C

 

[Gene_Hobbs]

figures 6 and 7 appear to be missing so we have requested a better copy from the author...

Lew sent me a better copy of his paper that includes fig 6 and 7. It has now been uploaded. Thanks. -G



Rubicon is participating in the Great Human Race 5k Run/ Walk in Durham, NC, USA on March 21st. Please consider sponsoring our team. More info available here.

 

[Randy43068]

No doubt about it: argon reduces heat transfer better than air!

Definitely not a placebo effect! Well, wait a minute now....At least not if the diver purged his suit at least 6 times to get that, roughly, 20% improvement.

Question: How many divers actually purge their suits at least 6 times with the argon? If they didn't purge 6 times, how much less improvement did they achieve? Did they still sense a significant improvement? Sounds like many still felt it was significant. Was it?

Actually, I never doubted that argon reduced heat transfer, just whether it's worth the trouble when other simpler methods may work better, such as using more insulation, using more air in the suit, avoiding constriction, etc.

I'd love to see a study of the thermal effects of simply using more air in the drysuit, of air that stays drier when purged more often during the course of the dive, which often happens as a consequence of having more air in the suit, and of simply increasing insulation in areas of high heat transfer.

I'm going to guess the improvement might be greater than 20%....it sure feels like it! And I know it's not a placebo effect!

Of course, there are drawbacks to using more air in the suit. Simplicity isn't one of them, though....

Dave C

That's what I maintain. One would have to replace most of the air with argon in his or her suit to make much thermal difference. I know the blast of inflation is warmer if it's argon, rather than air but not sure it's worth rigging argon up just for that.