Question Rec cold water diver: Single, Double or Sidemount? (focus on safety)

[Wildsparrow]

Yes, and there is a very interesting article I just found today, explaining all the details:

https://divelab.com/download/procedures-and-guidelines/ScubaRegulatorFreezing-ChillingFacts-4-9-14.pdf

I follow another thread about the DIN EN250 (some people claim it's useless) and there is a EN250A which means the regulator set (1st and two 2nd stages) is rated for 2 peoeple breathing from a single first stage at cold water. Unfortunately, there is also a EN250A >10°C... so, people need to be aware of the differences and exactly need to look what is engraved on the first stage ...

To answer my own question on the H-Valve: It seems that the probability of a free flow/ ice build up is higher with more pressure in the tank.
I will probably encounter water temperatures between 4°C and 10°C at my local dive spots during the colder seasons, so a good cold water setup is key for me. And though I don't want to dive solo, I prefer to be not dependent on a dive buddy.

 

[SlugLife]

It seems that the probability of a free flow/ ice build up is higher with more pressure in the tank.

At the first stage, but not the 2nd stage. The first-stage brings the tank pressure (3500 psi, 500psi) down to about 140psi, which your 2nd stage then brings down to about ambient-pressure. So, your 2nd stage gets the same amount of pressure regardless of tank-pressure unless your pressure is quite low.

The more the air expands due to pressure drop, the more the temperature drops. (classic physics pV=nRT)

(Some minor simplifications in there, but I didn't feel like writing a much longer post)