Argon use with Drysuits

I am interested in using argon with my DUI drysuit.

I have heard that:

(1) It keeps you warmer than air will.

(2) It does not create "bouancy" the way air does, allowing for the use of the BC for bouyancy control, as well as a major reduction in the amount of weight worn.

Does anyone have any hands on experience with argon? Are the above exagerations or "wives tales"? Or is Argon the cold water photographers best tool to replicate wetsuit diving and trim?

(1) is true. Ar is a better thermal insulator than air.

(2) is complete nonsense.

dah!!! I just spent 15 minutes writing a reply that was lost!!

It had specific heats, molar masses everything. In a short non technical way. Argon is a denser gas with a lower specific heat so it will resist heat transfer and insulate better than air.

As for the bouancy issue, I do not believe it to be the case. I dive a drysuit and have tried argon. The mass of the gas is not that much different and when you get them wet everything changes. So minor differnece in mass can be accounted for by changing volumes ie you put less gas in your suit. technically you will be heavier on argon, in case something goes wrong (free flow) you should weight for air. Just my opinion. that way you can switch to an extra inflator hose or your bcd hose to fill your drysuit and vent it as you normally would during an ascent.

Hope that helps and I wonder where my "scientific" post went. Sometimes being an engineering student get the better of me.

Aaron

(2) is complete nonsense.

Thanks Herb.

Is there ANY benefit in this department?

As argon is so much denser than air (albeit still less dense than water) does the bouyance factor of the inflated drysuit get reduced at all?

I had been told (by a retailer selling an Argon system, so, consider the source!) that you could "fill the suit while descending and "tighten" the release valve, thereby ignoring the suit inflation for the rest of the dive. you then used your BC to control and maintain bouyancy. During ASCENT, the valve would release Argon as necessary to not overstress the suit.

This sounded a bit "too good to be true", therefore this post!

Also, based on this info, I made the assumption that some of the additional weight I carry for purposes of warmth could be removed. I was at one time able to reduce my weight to 11 pounds, however I froze due to lack of air in the suit. I now carry 28 pounds to stay comfortable.

This is the weight I was hoping to shed.

Thanks Aaron. Dont feel bad. I was typing the above while you were losing your tech data!

(2) is complete nonsense.

 

Thanks Herb.

 

Is there ANY benefit in this department?

 

As argon is so much denser than air (albeit still less dense than water) does the bouyance factor of the inflated drysuit get reduced at all?

 

I had been told (by a retailer selling an Argon system, so, consider the source!) that you could "fill the suit while descending and "tighten" the release valve, thereby ignoring the suit inflation for the rest of the dive. you then used your BC to control and maintain bouyancy. During ASCENT, the valve would release Argon as necessary to not overstress the suit.

 

This sounded a bit "too good to be true", therefore this post!

 

Also, based on this info, I made the assumption that some of the additional weight I carry for purposes of warmth could be removed. I was at one time able to reduce my weight to 11 pounds, however I froze due to lack of air in the suit. I now carry 28 pounds to stay comfortable.

 

This is the weight I was hoping to shed.

The difference in the density of gases makes no difference in bouyance since both are so much lighter than the water it's displacing. So the first claim in (2) really is nonsense.

However, if you can reduce the dry suit inflation you need to keep warm with Ar, that reduction can decrease the overall weight you need. You have to weight that against the additonal weight of the Ar bottle and regulator. In most case, I don't think you will come out ahead. In no case is it ever safe to over tighten the release value in your dry suit!! If the dry suit inflation you need to stay warm is affecting your bouyance control, add layers to your underware don't just keep putting more air in.

Thanks. I had a feeling the info I was getting was too good to be true, so I wanted to hear from divers that had used it, or that do now!

I may still go that route eventually, but only with the expectation of staying a bit warmer.

Thanks. I had a feeling the info I was getting was too good to be true, so I wanted to hear from divers that had used it, or that do now!  

 

I may still go that route eventually, but only with the expectation of staying a bit warmer.

I find it unnecessary for Monterey diving. It does get chilly when the water temp drops to 45 F, but not intolerable. I know lots of people around here who swears by it. Some of them are tech divers. When you start adding Helium to your breathing gas, the advantage of Ar becomes much bigger. I would recomend that you experiment with underware before deciding on Ar.

I definilty agree with Herb on this one. It would be rather dumb to tighten your vent valve. Most dives are at least a little multilevel and gas in the suit expands and contracts. You want to be able to vent the expanding gas.

It has been my experience that persons new to drysuit diving often

1.)wear cotton or other non wicking fibers

2.) have too much gas in their suit.

Just by wearing the proper layers you'll be amazed at the warmth. I dove with a friend who wore cotton sweatpants, sweatshirt, and a $1500 drysuit. After buying a some polypropelene long underwear and a fleece, he was amazed at the difference. My suggestion is to look closely at your layers first and then if you need argon look there.

Aaron

I guess I need to qualify this post.

I am not new to drysuits, and use DUI underwear. I have over 250 dives on my year and a half old DUI.

I stay warm with the present setup, and am not weighted any more or less than most of the other dry divers I know, although I probably could reduce the weight I wear if I were warmer.

If Argon is significantly warmer, then I could shed at least 8 pounds in my local waters and when diving Monterey or Barclay Sound I could keep my "normal" weight and stay warm.

Yes, I was hoping for added benefits, but if they are not to be had, then maybe the hassles of Argon fills are not worth it, and I should consider a second set of undergarments for really cold water.

Goodness, you should be giving me tips on the drysuit... I don't dive so often in the cold (there's not a lot of exciting diving in Pennsylvania)

As for the new undergarments I've heard amazing things about weezle wear http://www.weezle.co.uk/ They have a few American distributors.

Who else would know more about cold water diving than the British, perhaps someone else on the board could help you out with more information about the weezle wear.

Aaron

I guess I need to qualify this post.

If Argon is significantly warmer, then I could shed at least 8 pounds in my local waters and when diving Monterey or Barclay Sound I could keep my "normal" weight and stay warm.

 

Yes, I was hoping for added benefits, but if they are not to be had, then maybe the hassles of Argon fills are not worth it, and I should consider a second set of undergarments for really cold water.

I have to agree with the previous comment about dropping lead. If you are overinflating your suit to stay warm, you need more or better underwear. Better socks, a thin polartech layer, or vest can work wonders.

And Argon IS warmer than air, my wife won't dive without it anymore. You WILL be dropping lead in any case. The Argon bottle & 1st Stage will probably be 4 -5 pounds negative.

Dave

Try getting a good quality synthetic long underwear to wear underneath your drysuit undergarments. When I started with my drysuit, I was wearing shorts and a cotton t-shirt under my Andy's Undies polartec suit, and I was constantly cold. The conclusion I came to was that because the suit was so warm, I was working up quite a sweat (unbeknownst to me) before I got in the water. The polartec suit can only wick so much to the outer layer, so some amount of sweat was staying close to my skin and making me cold.

Now, no matter how hot it is outside (up to 90F or so in NJ), I add a layer of synthetic long underwear underneath the suit, and I stay warmer in the water.

I've thought about argon, and when I get in the water with Trimix I'll definitely use it (because as someone mentioned, He added to a suit is coooooolllld), but as long as I'm on air it's not worth the hassle.

Tom

I had been told (by a retailer selling an Argon system, so, consider the source!) that you could "fill the suit while descending and "tighten" the release valve, thereby ignoring the suit inflation for the rest of the dive.  you then used your BC to control and maintain bouyancy.  During ASCENT, the valve would release Argon as necessary to not overstress the suit.

Many of the divers that I dive with do something similar to this to conserve Argon during a dive. If you flush the suit with Argon after you put it on, and them offset the suit squeeze during descent, you can close your exhaust valve a bit so you don't lose argon unless you really want to. I personally don't find the loss of a bit of argon to be an issue, but I do see many local divers close their exhaust valves a twist at depth.

I find argon allows you to extend your bottom time by slowing your heat loss. If you are comfortable making 45 minute dives filling your suit with your back gas, then using argon will allow you the same comfort out to an hour of so. If you are doing longer decompression dives (say 90 minutes), using argon becomes a very effective way to stay warm for that extra 30 minutes of exposure. I really don't see any difference in the first 45 minutes of a dive, and when making shorter dives typically just use backgas unless it contains helium.

Scott (Boydski) Boyd

Thanks again guys! I really appreciate all this input.

I think I will try a set of silk long underwear localy for now, and try to rent an Argon setup for Barclay Sound. most of my dives average an hour, and I get cold easily!

Even using backgas, I tend to give the exhaust valve a half twist at depth to allow me to get vertical on walls without loosing to much air. It is a PITA to get in position for a shot, and suddenly get heavy as you are ready to shoot.

Of course I reset the valve after taking the shot!

stay warm with the present setup, and am not weighted any more or less than most of the other dry divers I know, although I probably could reduce the weight I wear if I were warmer.  

:shock: Wow, 28 pounds is a lot Rich (relatively). If your intent is to drop weight (partly) get a SS backplate and wings, (u already use a steel tank?) SS BP is -6#, and you'll probably find that the BPW setup allows you to drop 2 -4 # just from getting away from bulky BCs.

I'm a bit bigger than you and I wear 12# of lead in my drysuit (add 6 for BP, 6 for tank, 2 for STAs, and that's 24 or so......)

Chris

I hate to rain on this parade, but there is no documented benefit in terms of body warmth/core temperature using argon in a double blind study where argon was compared with air.

Citation

Undersea Hyperb Med. 2001 Fall;28(3):137-43.

 

 

 

Title: Thermal insulation properties of argon used as a dry suit inflation gas.

 

Authors: Risberg J, Hope A.

 

Norwegian Underwater Institute and Royal Norwegian Navy, Bergen.

 

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 approximately 10 m for 60 min. 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 approximately 200 ml less (P < 0.05) during the air than the argon dives. Rectal and all skin temperatures 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 min.

 

Publication Types:

Evaluation Studies

 

PMID: 12067149 [PubMed - indexed for MEDLINE]

Important points here: They compared AIR and argon, not heliox/trimix, where the heliox/trimix has a severe adverse effect on body warmth. Thus technical divers using helium mixes should use something other than that the helium mix to inflate the suit, but you may as well use air.

Subsequently, people have discussed the "perception of warmth" with argon. One quite reasonable explanation I have seen is that people often use welding grade argon, which has a fair bit of carbon dioxide in it. (Fair bit meaning up to 25% in some mixes used as shield gases for MIG welders). When carbon dioxide dissolves (ie, in sweat on the skin surface) it produces carbonic acid, which is a mild irritant and leads to peripheral vasodilation, thus more warm core blood is brought to the skin surface and you get a perception of warmth.

Thats not rain Craig, it is the kind of info I was looking for!

Thanks!

I thought argon was warmer because it came from a red bottle.

That's an interesting article and I'm going to have the full text sent to me from either DAN or the medical school Having just taken a bioheat transport class, I'd like to work out that problem. Theoretically argon should be warmer. It has a lower specific heat.

I found a decent article for those that are interested in further argon information (warning there is math)

http://www.decompression.org/maiken/Why_Argon.htm

Unless you are really interested skip the math and look at the Field practice and conclusion.

Aaron