Thread: Wet (Damp) Synthetic insulation: How useful is it?

Im curious. I know down looses all its insulating properties when it gets wet but does anybody have any data on how much of its insulating properties synthetics retain when they get wet? I know its going to depend on how wet the insulation is as well as a few other thing that skip my mind right now.

Speculate away

I stood all day in the rain in a Mammut ajungilak belay jacket in windy wet shitty conditions and stayed warm relative to the amount of physical work I was doing. I was impressed. My shell was useless, but the synthetic jacket kept me ok.

At days end the insulation was not sodden except in the areas where gravity took the water. Elsewhere, I reckon my body heat helped keep the jacket dry on the inside. At no point did I get more than damp inner garments except the lower 2/3rd of my forearm.

i dont have any data, but from my experience, insulation decreases if really damp, but not too much. never had any insulating stuff soaking wet, so cant comment on that.
i still use down, because you can always throw a waterproof layer on top and im not wearing my insulation when im active enough to really sweat...

freak~[&]

My unscientific impressions:

If you have two similarly constructed 16 ounce jackets, one filled with high quality down and the other with primaloft type stuff, the down will be a good bit warmer.

If you get them both soaking wet they will provide similar insulation.

But down sucks up water more easily than synthetic fill, and it dries slower.

Originally Posted by Hohes

I stood all day in the rain...
windy wet shitty conditions and stayed warm relative to the amount of physical work I was doing. I was impressed.

At days end the insulation was not sodden except in the areas where gravity took the water. Elsewhere, I reckon my body heat helped keep the jacket dry on the inside.

This is what I have enjoyed for the last <20 years since I got my Marmot Primaloft sweater and Ive used it for everything.
It was finally time to buy a replacement and these days the marketplace is full of these types of jackets so there was no problem finding one.
Except the "primaloft" has changed! wtf?
Ive bought three different jackets from different good brands and all have been the same.
This new "primaloft" (not like my old jackets gold stuff) makes this summers priority to repair my old jacket. Again.

Does anyone know what happened? When did they change production enough to destroy all the excellent qualities it had?
I know primaloft lost out on the first huge "war of the synthetic downs" to polarguard since it didnt feel as "downy" in the stores and so vanished from the market for a couple of years.
But I was so certain that the success of primaloft for the last five to six years was due to the excellent qualitities that my jacket from 1994 had.
Apparently not. Or have I missed something?

I worked with these numbers many years ago. Memory seems to feel that - Wet (soaked through); synthetic insulation was 25% of it's normal effectiveness, down <10%.

In real terms; synthetic will still be of benefit. With down, you may as well not be wearing it.

Edit: I expect synthetic insulation to have improved a bit with technology in the 12 odd years since I was involved with this sort of stuff. I can't see that down can have improved much, or at all.

Depends on the synthetic insulation. Insulating properties of synthetics when wet varies quite a bit from brand to brand. My experience is from awhile ago: Mid-1990s Primaloft was worthless when wet, not much better than down. OTOH, when mid-1990s Polarguard got soaked, one could wring it out and stay pretty warm.

I don't have much personal experience with the newer stuff cuz I use down sleeping bags and avoid getting my puffy jackets soaked.

I have a Patagucci Nano Puff which I've completely soaked a few times. It doesn't lose much of it's warmth even when it's dripping wet. Now, I'll admit that it isn't very insulative even when it's dry, so maybe there's just not very much to lose.

Another thing that's great about the PrimaLoft One in the nano is that it doesn't retain much water. i.e. it doesn't get heavy even when it's sweated out.

It still depends of loft, the more loft, or physical space between you and the weather, the warmer it will be. Down clumps up and looses nearly all it's loft. Products like polartech still retain a lot of loft, and therefore still insulate. Same with wool. It also depends on how much water the fabric holds, since water will wick away heat. Cotton holds a shit ton and have little value when wet, where as wool doesn't hold as much. once again polartech type fabrics retain the least water and maintain the most structural loft, therefore stay the warmest. Wring out a soaked polartech layer and put it back on and you will be surprised how warm (relatively speaking) it is.

Originally Posted by I've seen black diamonds!

My unscientific impressions:

If you have two similarly constructed 16 ounce jackets, one filled with high quality down and the other with primaloft type stuff, the down will be a good bit warmer.

If you get them both soaking wet they will provide similar insulation.

But down sucks up water more easily than synthetic fill, and it dries slower.

This correlates to my experience. Meaning, that over multidays the wet down will feel colder as it dries slower.

I always find it funny how the adage goes, once down is wet it loses all insulation. Not my experience in the wilds.

Primaloft itself absorbs less that 1% of it's body weight in water even when fully submerged, so it still insulates just as well.

Not sure where you got that spec, but IME, the first generation of Primaloft broke down into a worthless pulp when it got saturated, no better than wet down.

True that modern synthetic fibers absorb little water. But the insulation batting does create a medium to old water in between the fibers. Synthetics (excluding first generation Primaloft and maybe others) are superior to down because they can be wrung out.

one important factor is cold water is still cold water.

Originally Posted by Danno

one important factor is cold water is still cold water.

Good point. Cold water takes a lot of BTU's to make it warm water.

Also, I think the biggest determining factor in this argument is whether the water can evaporate or if it is trapped. So if you have a synthetic covered by a gore-tex shell it will insulate fairly well. That same wet synthetic exposed to a 20mph wind and allowing evaporation is probably going to remove more heat than it traps.

In the event that you sit or lay down on snow or a cold log, etc and allow conduction to draw the heat out of the water, well, you're fucked.

Originally Posted by neufox47

Good point. Cold water takes a lot of BTU's to make it warm water.

Also, I think the biggest determining factor in this argument is whether the water can evaporate or if it is trapped. So if you have a synthetic covered by a gore-tex shell it will insulate fairly well. That same wet synthetic exposed to a 20mph wind and allowing evaporation is probably going to remove more heat than it traps.

In the event that you sit or lay down on snow or a cold log, etc and allow conduction to draw the heat out of the water, well, you're fucked.

I remember years ago camping in a torrential rain, and water puddled up in the tent (learned a lesson there). Sure, my synthetic bag probably did a better job that if it had been down, but I was still sleeping in a puddle of cold water. The statements that synthetic still keeps 80% of its insulating power (or whatever number) may not be wrong, but can be misleading. because I was definitely not that percentage warm as compared to sleeping dry.