How cold does it need to be for a Cold Reg?

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stever2002

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If I dive in the local quarries, the water temp is in the mid 40's to mid 50's (degree F) at depth during the Summer months. I have not yet ventured off the NJ shore, where I understand it is also chilly year round.

If I do quarry and NJ coast dives (all in Spring/Summer) do I need a cold water reg? At what temperature water do I need to consider a cold reg? :snorkels:

Dive Safe,
...steve...
 
The generally accepted term, in regard to regulators, is 50 degrees F. Practically speaking potential problems with freeze flows begin to occur at water temps in the 40-45 degree F range.
 
Bad technique will male the best cold reg fail. Good technique will make any reg OK down to 45 degrees or so.
 
Correct me if I'm wrong, DA, but isn't one of the things that makes a reg a "cold water reg" tuning down the IP about 10psi? I have Aqualung Legends, the Extreme, and besides the lip guard, that's the only difference between it and the "regular reg". That being the case, the shops in the OP's area should be tuning down the regs for their environment.
 
Hey Stever2006
Straight from the manual on our cold water regulators "ideally suited for water below 50*F/10*C". Some of the features they add for colder water are: Heat exchangers, dry chambers, materials that don't harden when cold and lip shields to keep you just a little warmer. Hope this info helps.
Britt :fish:
:fish:
 
My Zeagle Envoy Deluxe and Octo manual says:

"The Envoy regulator is not specifically designed for use in cold water.
Cold water is defined by C.E.N. standards as water at a temperature
of 50 °F
(10°C) or lower. In cold water there is a risk of the first or second
stage freezing. The risk of freezing is increased as the ambient temperature
gets lower, the air flow increases and/or the moisture content
of the air supply increases. Regulators for cold water use should have
environmentally sealed first stages to prevent water entry and lower
the chance of freezing. If you plan to dive in very cold water, Zeagle
has other models available that are more suitable. Ask your Zeagle
Dealer for details and recommendations."

-Garrett
 
It also depends on whether you are diving salt or fresh water.
I believe that in the ocean in most places you don't need anything special.
 
paulwlee:
It also depends on whether you are diving salt or fresh water.
I believe that in the ocean in most places you don't need anything special.

you obviously haven't dived the north coast of Newfoundland in winter...
 
Dive-aholic:
Correct me if I'm wrong, DA, but isn't one of the things that makes a reg a "cold water reg" tuning down the IP about 10psi? I have Aqualung Legends, the Extreme, and besides the lip guard, that's the only difference between it and the "regular reg". That being the case, the shops in the OP's area should be tuning down the regs for their environment.
On some models, lowering the intermediate pressure helps as it lowers the flow rate overall.

There are a few different approaches to cold water first stages.

1. Some are designed to allow for adequate heat transfer to ensure the first stage can absorb enough heat from the water to make up for the heat it loses to the expanding air going through it. This approach can be problmeatic at high flow rates - and this is where detuning the IP to the low end of the range - around 120 psi - can help.

2. Other designs use a non freezing filler material for the ambient pressure portion of the reg so that ambient pressure can still be transferred but water cannot enter te ambient chamber. (If water is allowed to enter an ambient chamber where the metal surfaces are well below freezing, water can freeze to those surfaces and prevent the piston or diaphragm from returning to the closed position after a diver inhales - this will result in a freeze flow that further cools the metal surfaces and will turn the first stage into a big ice covered blob.)

The normal filler material is either silicone grease or an O2 compatible grease held in place by a boot or alterantively silcone oil or alcohol retained by a separate diaphragm. However some models use an air filled ambient chamber where additional air is added either by an orifice bleeding air into the chamber at a constat rate or with a demand valve arrangement (usually a diaphragm acting on a schraeder valve).

3. The final approach is to use a fully sealed air filled design where the diaphragm moves inward to press on a pressure transmitter to balance the pressure but does not allow water to enter the ambient chamber. These have to be carefully designed so that the internal volume of the chamber does not exceed the volume that can be managed by the diaphragm. But the design is nice as it does not rely on oil or grease that can leak out nor does it have the limitations of a first stage that relies soley on heat transfer.

Second stage freeze ups were unheard of in the days of metal second stages as the heat transfer traits of their metal construction ensured that the internal parts stayed near the water temp. Second stage freeze ups were still reasonably rare with plastic cased second stages with metal air barrels, but they are distressingly common on plastic second stages with plastic air barrels and I would not recommend a reg of this design for extremely cold water (below 40 degrees) use and that unfortunately eliminates a lot of otherwise very good second stages.
 

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