Argon, Is it warmer?

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Bubble Boy

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Last year at the UHMS (Great Lakes Chapt) there was a presentation on the myths in diving. The one presenter stated that argon as a dry suit gas for warmth was simply a myth. I seem to find it warmer than air but is it all psycological as the speaker suggested?
 
It is warmer than air but it's way warmer than Helium. The trick is to purge the air from your suit and fill it with argon and purge again. I go through the cycle twice. The idea is to get as much of the air as you can out so that the gas that is in the suit is argon.
 
MikeFerrara once bubbled...
It is warmer than air but it's way warmer than Helium. The trick is to purge the air from your suit and fill it with argon and purge again. I go through the cycle twice. The idea is to get as much of the air as you can out so that the gas that is in the suit is argon.

That would explain why I would have said "no appreciable difference".

I do not recommend inflating your suit with trimix unless you have no option - it is damn chilly.

Duncan
 
A fairly comprehensive study done by the Swedish Navy indicated there was no measureable difference between air and argon.

Here are just a few paragraphs from the study:

Thermal Insulation Properties of Argon Used as a Dry Suit Inflation Gas

J Risberg and A Hope

Thermal Insulation Properties of Argon Used as a Dry Suit Inflation Gas.
Undersea Hyper Med 2001;28(3):137-143

"Uncontrolled observations from the "technical" diving community claim superior thermal comfort when replacing air with argon as dry suit inflation gas during diving.
The objective of the present experiment was to evaluate the effectiveness of argon compared to air during cold water diving. Body weight, urinary output, and rectal and skin temperatures were measured in six naval divers during two dives to 10 m for 60 minutes.
Level of thermal comfort was reported. Dry suit gas was either argon or air, divers and scientists were blinded for gas identity.
Urinary output was 200 ml less (P<0.05) during the air than the argon dives. Rectal and skin temperature decreased significantly in both groups during the dive but no difference was measured between argon and air dives. Thermal comfort was not different between the groups. Replacing air with argon neither improves subjective impression of thermal comfort nor attenuates core or skin cooling during cold water diving to 10 meters of sea water for 60 minutes.

As far as we know, the theoretical benefit and subjective experience with argon have previously not been challenged by blinded tests. Having a density of 25% higher than air, technical divers claim to hear and feel the difference in suit inflation rate. Blinding may thus be difficult for divers having used argon previously. There is a possibility that the superior thermal comfort is anticipated rather than real. Second, many divers use an Ar-CO2 blend commercially available as welding shield gas. The added CO2 may theoretically form carbonic acid (H2CO3) at skin surface moistened with sweat or water. One may speculate whether this weak acid (pKa=6.4) may irritate the skin sufficiently to cause a sensation of thermal comfort.

The results of this study indicate a lack of positive thermal effects in operational diving, forcing us to recommend air as dry suit inflation gas for military diving and probably also in recreational (technical) diving.
http://www.scubadiving.com/talk/read.php?f=1&i=512833&t=512833
It's an entirely different story when compared to helium though.
 
What I would like to see is the curve of the cooling rate. I believe there isn't a difference after a cold 60 min sive bu what about 15 min or 30 min? Also did they flush the suit.

We do not use welding argon because the carbonic acid causes rashes not the illusion of warmth.
 
Argon is clearly better than air in reducing heat exchange. that is a proven scientific fact . that is why glass dual and tri pane High efficiency windows are filled with argon . but there a lot of variables in drysuit diving that can reduce the benefits ,not purging the suit ,what undergarment you have, fit of the suit etc
joens
 
You really don't want to compare a window to a drysuit, do ya? :mean:
You'd have to stick drysuit undies in the gap along with the argon.

Suits were very well purged and even checked with an O2 meter, yielding 0%.
Cooling rates were nearly identical.

After the weekend, I'll scan the 7 pages into a pdf document & email to anyone that's interested, otherwise its like discussing creationism vs evolution.
:bonk:
 
Bob3 once bubbled...
A fairly comprehensive study done by the Swedish Navy indicated there was no measureable difference between air and argon.

I saw that study, it was rather amusing. They used the wrong kind of insulation, and that overwhelmed any differences between the inflation gasses, so of course the divers got cold. There were other flaws in the experimental methods as well but that was the big one.

The US Navy did similar tests years ago, and did them correctly (i.e. with thick and noncompressible Thinsulate insulation), and found that argon definitely does help.

Here's a web page with the heat transfer calculations in case anyone is interested. http://www.decompression.org/maiken/Why_Argon.htm
 
Thinsulate is the wrong kind of insulation material to use if you expect to get any benefit from a gas change. The marine grade Thinsulate is fairly closed cell, there will be very little absorption or exchange of any suit gas.
Marine grade Thinsulate will retain approximately 90% of its insulation qualities when wet, give you a good idea of just how easily it can be "purged".
 
from DUI web site

"G Series 100% Type-B Thinsulate®

Based upon US Navy testing, Type-B Thinsulate® provides higher levels of insulation per unit-thickness and maintains the highest level of insulation when wet, over other materials tested. An excellent choice for divers in demanding underwater environments and doing decompression stops. Available in two thicknesses 200G - 200 gm/m2 Type B Thinsulate® 400G - 400 gm/m2 Type B Thinsulate® "

and Air blows right through it.
 
http://cavediveflorida.com/Rum_House.htm

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