The Kraken
He Who Glows in the Dark Waters (ADVISOR)
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Will wool keep you warmer or not?
wetsuits and wool
- Thread starter jviehe
- Start date
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miketsp
Contributor
The Kraken:
Well I read through the nice technical explanations and I'm a little sceptical about discussions of water vapour in a saturated situation. Water vapour is at least 1500 times less dense than liquid and is not the main contributing factor, which is conduction.
I agree with DMBIrish that the wool will keep you warmer, yes, but because, as he stated, it will help prevent water movement around the inside of the wet-suit.
OP
I ended up buying the Merino hooded vest. I dont really know whether the wool works, but im inclined to beleive that the ad or disadvantage is neglible in practical terms.
As a side note, the merino seems to dry faster than neoprene.
As a side note, the merino seems to dry faster than neoprene.
Corigan
Contributor
jviehe:
I have a Pinnacle Polar and it dries super quick. I also don't know if the wool makes it warmer or not, but I've dove it down to 44 degree water and been plenty warm.
Matt
WarmWaterDiver
Contributor
The discussion on exotherm of hydrophilic materials is OK, but did not quantify the magnitude of the exotherm. Drying agents (dessicants) like silica gel, and particularly molecular sieve, where a small pellet about the size of a grain of rice has hundreds of square meters of surface area per gram (extreme porosity - zeolite crytal structure) can exert a significant and in some cases even dangerous exotherm when slightly dampened. But, when these materials are fully soaked, the heat sink of the water itself does not appreciably rise, and water has the highest heat capacity of all common substances. In fact, if slightly dampened and dangerously heating, flooding these materials with quenching quantities of water is one of the potential remedy actions. So, the exotherm effect of the wool must be close to immeasureable when fully sodden, but resistance to flow via tortuous path between the fibers, limiting convection, like any other 'wooly' insulation is reasonable as previously discussed.
simonk999
Contributor
Regarding the article posted by aquawookie, and the refutation of it stating "but not underwater", I'm inclined to think that it's not so much being underwater (i.e. completely wet) that changes things, but the pressure -- if a wool fiber has somewhere to store water vapor, presumably that means, in layman's terms, it's a hollow fiber (and I believe this is why wool insulates when wet, above water). Question is, does this somehow get equalized so that it doesn't collapse as neoprene cells do? If this is the case, that the water vapor can equalize the hollow space, then I would definitely believe that the wool lining helps.
Plus, in Pinnacle's literature, they make a point of saying that the wool lining gives you 2-3mm of extra insulation thickness, in that because the lining becomes saturated, and water is incompressible, that 2mm stays 2mm at depth, and once warmed to body temperature, doesn't act as so much of a heat sink. Meanwhile, the neoprene part is becoming thinner because of the pressure. So a wool-lined pinnacle suit is warmer mainly because it provides a thicker layer of insulation, i.e. their 7mm + wool lining suit is ~10mm in practice. I'm inclined to believe this also.
But maybe I'm just a sucker for marketing literature...
-Simon
Plus, in Pinnacle's literature, they make a point of saying that the wool lining gives you 2-3mm of extra insulation thickness, in that because the lining becomes saturated, and water is incompressible, that 2mm stays 2mm at depth, and once warmed to body temperature, doesn't act as so much of a heat sink. Meanwhile, the neoprene part is becoming thinner because of the pressure. So a wool-lined pinnacle suit is warmer mainly because it provides a thicker layer of insulation, i.e. their 7mm + wool lining suit is ~10mm in practice. I'm inclined to believe this also.
But maybe I'm just a sucker for marketing literature...
-Simon
JimC
Contributor
simonk999:
Where did the energy that warmed (and continues to keep warm) this layer of water come from? How fast is this water conducting that heat away? How quickly is that warm water seeping away and being replaced by cold water?
It took a LOT of your body energy to get it warm, water has an inredibly high specific heat, higher than any ther comon substance (20.7 J/mole K for air vs 75.2 J/moke K for water). It conducts quite well and requires a lot of energy to keep warm, ~24 times more conductive than air. The wool likely will help with the water transfer, but thats nothing a suit that fits well can't do already.
Water is a poor insulator, we learn that in Open Water. 2mm of traped water is a LOT worse an insulator than 2mm of traped air. Not only does water conduct 24 times faster, but it also takes 4 times as much energy to get to the same temperature oin the first place. Thats almost 100 times the enrergy as air.
OP
Yes, but the claims of wool are that it is exothermic, prevents the water in your wetsuit from circulating by absorbing water, and preventing compression. Does this add up to warm? Who knows. I dont think theory can answer this one.
JimC
Contributor
jviehe:
See post #25 about the exothermic stuff.
I don't see it providing much advantage over a suit that fits well re water transfer, but if there is any validity to the things being warmer - this is where to look. Unfortunatly its basicaly imposible to quatify this one.
How exactly does it prevent compresion? No, the water in the suit dousn't compress, but the air in the suit still does. Water is a BAD insulator, not compressing it isn't going to do anything to make it better at that. No thickness of water layer is going to be a good insulator. Infact I dare say the thicker the water layer the worse off you are, becuase it is going to take more energy to get it warm and keep it warm.
If water was a good insulator we would dive flooded drysuits with no undies, like hot water suits without the surface supplied hot water!
SueMermaid
Guest
:15a: Just when I thought wetsuits could not be less comfortable.
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