horizontal ascents

[rjack321]

Breathing a highly narcotic asphyxiant is rarely a good idea. Even in Phil's hottub.

 

[MXGratefulDiver]

Breathing a highly narcotic asphyxiant is rarely a good idea. Even in Phil's hottub.

... unless you're referring to Phil Lesh ...

... Bob (Grateful Diver)

 

[FishTaco]

The there's the whole question of is argon in fact any better than air? Or is the whole thing a scam? Especially if you dive horizontal!

Argon does minimize heat transfer, that's why it's used as a filler gas in thermo-pane windows.

Chris

 

[Thalassamania]

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

• 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.
PMID: 12067149 [PubMed - indexed for MEDLINE]

 

[Teamcasa]

Argon does minimize heat transfer, that's why it's used as a filler gas in thermo-pane windows.

Chris

I believe its used because it is inert, the heat transfer is virtually the same as regular air.

Dave
DDHF

 

[Soggy]

I believe its used because it is inert, the heat transfer is virtually the same as regular air.

Dave
DDHF

Argon has roughly 1/3rd less heat transfer.

This is a never ending debate and people always cite that Norwegian Navy study where, if I recall, they did not purge the drysuit of air and just topped off with argon. Me, I know that I stay more comfortable with argon in cold water, so the results of the study are unimportant.

 

[FishTaco]

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.

How much gas was in the test divers drysuits?

Were they shrink wrapped, or were their undergarments fully lofted?

Were the divers verticle or horizontal?

How do you explain away the chemical properties of Argon being better (theoretically) than air at minimizing heat transfer?

Chris

 

[Soggy]

Here's a link to the full article: http://archive.rubicon-foundation.org/2380

This was provided to me by Gene Hobbs. It should answer a lot of questions people have.

Registration (free) is required to download the pdf.

 

[rjack321]

Also they used neoprene drysuits and "wooly bear" undergarments. I doubt much of the Navy's diver's insulation was provided by the loft of the undergarment at all in these conditions. Vs. a shell suit which is most commonly used by DIR divers, where 100% of the insulation is from undergarment loft.

Everyone posts that abstract, but the study behind it is craop.

 

[Thalassamania]

Also they used neoprene drysuits and "wooly bear" undergarments. I doubt much of the Navy's diver's insulation was provided by the loft of the undergarment at all in these conditions. Vs. a shell suit which is most commonly used by DIR divers, where 100% of the insulation is from undergarment loft.

Everyone posts that abstract, but the study behind it is craop.

We're lucky to have an expert like you here to tell us that. Would youy care to tell of of your degrees, your work in the field, your publications and to expand a bit beyond, "it is crap?"