Argon worth it?

[Storker]

The biggest problem with using Argon in a drysuit is all the moisture given off by the body is trapped

Darned good point. While Ar has a noticeably lower thermal conductivity than air, how significant is that difference when the gas in your undergarments is at 100% relative humidity? Water vapor has a pretty decent thermal conductivity, so comparing thermal conductivity coefficients for the dry gases (Ar vs. air) is at best misleading.

 

[Akimbo]

While Ar has a noticeably lower thermal conductivity than air, how significant is that difference when the gas in your undergarments is at 100% relative humidity?

As a reference for other readers:

The values for Air, Argon, Helium, and water are of particular interest. In the case of Helium, you also have to consider that many mixes use much lower percentages of Oxygen resulting in effectively higher thermal conductivity.

 

[Storker]

As a reference for other readers:

View attachment 490562​

The values for Air, Argon, Helium, and water are of particular interest. In the case of Helium, you also have to consider that many mixes use much lower percentages of Oxygen resulting in effectively higher thermal conductivity.

So. Ar has a 30% lower thermal conductivity than air, but OTOH water vapor is 24 times as conductive. Let's assume (yes, I know) that the gas in my drysuit is at 10 degrees C. That means that 2.5% of the gas in my suit is water vapor with about 24 times the heat conductivity of air, and that accounts for 50% of the total heat conductivity of my suit gas. So, switching from air to Ar should give me about 15% less heat loss if I don't consider convection. I don't think I'll bother with Ar...

 

[Superlyte27]

The question of this thread is "argon worth it?" That question goes beyond whether or not argon does a better job than air at keeping you warm. The question is whether that extra warmth, assuming it exists, is worth the extra cost and effort required to use it. I generally dive with a drysuit in three situations--open freshwater sites with temperatures in the high 50s, ocean sites with temperatures in the low 70s, and caves in the low 70s. I have only done occasional dives in the 40s, but they are actually the most instructive for this discussion.

I used to use argon with some frequency at the freshwater sites, but since we did not have a good way to bring it on extended trips, I used to use a big bottle and top it off with air as the weekend went along, so I was really using "airgon." In addition, without a booster, as the supply bottle pressure dropped, so did out argon fill ability, so we were once again forced to top off with air and use "airgon." Frankly, I never noticed a difference on those dives, and I eventually just went to straight air. I assume that the reason I didn't notice a difference is that I did not flush the suit as described in post #8.

What I have learned on those dives is that if I use my medium weight underwear, I am usually just fine using air for dives in the 70-80 minute range. On longer dives, I get cold, so on those dives, I put on my heavier weight underwear and stay toasty warm. On the dives in the low 70s, both ocean and cave, I am usually perfectly comfortable with my medium weight underwear on dives in the 70-80 minute range. The exceptions have been when I have had to work harder than normal in a cave, in which case I tend to get uncomfortably warm, especially if I wear a hood.

My few cases of colder water diving are most instructive. They were not really cold--about 46° F, but I made the mistake of wearing my warmest underwear and a hood while inflating with air. By the end of dives lasting for about an hour, I was sweating. I certainly did not need to be any warmer.

So, the moral of my stories is that if you have the right undergarment for a dive, there is no need to use argon, so that extra cost and effort is not worth it. I have never dived in truly cold water, and I have never done extended time dives. In those cases, I might very well become interested in using argon, but nothing like that is on my schedule these days.

I did 4 hour dives every day for almost 5 months in 30 degree water on surface supplied open circuit. Argon or air, there's little difference. It's almost inperceivable, certainly not worth the money or hassle for fills. Your money would be better spent on a heated vest.

 

[2airishuman]

The answer to "whether argon is worth it" should also address the safety risks it poses, since it is an asphyxiant, and being viscous and heavier than air can be difficult to expel from the lungs.

I've never found any reports of fatalities. I bet there are, at a minmum, some close calls that have occurred.

 

[Storker]

The answer to "whether argon is worth it" should also address the safety risks it poses, since it is an asphyxiant, and being viscous and heavier than air can be difficult to expel from the lungs.

NRK TV - Se Dykket

 

[northernone]

I don't bother with argon for fairly substantial dives in the home waters of the Arctic ocean.

It's another H̶y̶p̶o̶x̶i̶c̶ (edit: anoxic, thanks @Akimbo) gas to carry and another cylinder/reg to task load myself with in preparing for a dive.

Every added piece of equipment takes up mental bandwidth and its more gear to haul around and maintain. Thicker thermals are hard to beat (unless with a heated vest which I don't have yet)

I've not felt a significant difference in a few very subjective trials I did between argon or air in my drysuit though I've never purged my drysuit 6 times with argon prior to a dive and kept at low humidity. I'm also quite new to drysuits in general.

Regards,
Cameron

 

[rjack321]

The answer to "whether argon is worth it" should also address the safety risks it poses, since it is an asphyxiant, and being viscous and heavier than air can be difficult to expel from the lungs.

I've never found any reports of fatalities. I bet there are, at a minmum, some close calls that have occurred.

Because people get their micro pony bottles mixed up with argon? Doesnt seem to happen since its ridiculously easy to put this on your argon bottle. Argon Do Not Breathe Decal {8 x 3 in | 20.3 x 7.6 cm}

 

[2airishuman]

Blending errors with a gas that comes in a cylinder with the same valve as He
Mixup with pony cylinders on dives where you're not using a drysuit
Inhalation when doffing drysuit after a dive

Anyone who has never made a stupid mistake in your life, raise your hand

 

[Akimbo]

Blending errors with a gas that comes in a cylinder with the same valve as He Mixup with pony cylinders on dives where you're not using a drysuit Inhalation when doffing drysuit after a dive

Mistakes like that could happen since non-flammable and non-oxidizing gasses such as Nitrogen, Argon, or Helium use the same CGA-580 connection in the US; but they do have unique color codes. Honestly, the bigger argument against Argon is the lack of efficacy in the real world.