Drysuit gas

[limeyx]

I always use a separate cylinder for suit gas. I have never noticed a difference between air and argon. I do however always use argon when diving helium just in case (isobaric counter diffusion). I try to minimize any possible trouble.

I think unless you are at 500+ feet you are not going to have this issue (and then you probably have far more to worry about honestly

However, inflating with Helium is not pleasant even in 77F water...

EDIT: Actually this ICD is not relevant here I think, as it is supposed to happen when (as the linked article states) you switch to a mix with a large gradient of say N2 or I think also Helium. Some people believe it is more of a problem than others do I guess.

 

[vwdevotee]

What is Isobaric COunter Diffusion?

 

[tedwhiteva]

What is Isobaric COunter Diffusion?

If you REALLY want to know - but have a few minutes

CDG - Isobaric Counter Gas Transport

 

[Scubakevdm]

It was a reasonable study, and bears out the mathematics of the difference in thermal conductivity between air and argon, which is not great.

My subjective experience is different. I did a non-blinded and not completely controlled trial of air versus argon for suit inflation last January. We did three days of diving in 43 degree water. The first day, I had argon. The second, I had "airgon" (argon bottle topped off with air). The third, I had air. Judging from my SAC rate, the dives were all similar in level of exertion, except the last one, which was a drift dive. My subjective experience was that I was more comfortable the first day than the second, and the third was the coldest. It was enough to motivate me to make the relatively small investment in an argon setup for myself.

It would be interesting to run that again with air as the first day's suit gas and argon as the last.

 

[DeepSeaExplorer]

It would be interesting to run that again with air as the first day's suit gas and argon as the last.

That's exactly what I was thinking. Everyone gets cold after three days of diving. There is a problem with these types of subjective test, leading to false conclusions.

If someone were to put a recording thermometer in their pocket, I suspect they would be surprised at the results, or lack of. Helium Vs Argon is one thing, but I seriously doubt that anyone could tell the difference between Argon and Air.