Wind and eVent v.s. Gore-Tex

When I moved over from Goretex to Even I found I had to wear an extra layer on occasion.

Breathability cuts both ways. eVent is directly venting. Goretex is not. When heating up, you will feel clammy with Goretex significantly sooner than you will with eVent. And of course, the flip side will be true as well. eVent blocks a lot of wind to be sure — but not as much as Goretex. Neither is perfect in all conditions — but for me, I vote eVent over Goretex.

When hiking with the winds howling, I want a shell that can block most all of the winds but without making me sweat inside. I really dislike having to constantly zip and unzip; or worse, put on and take off my shell layer. Here, eVent is clearly superior to Goretex. But when at rest… if I find my eVent shell not warm enough, I can put on an insulation layer. Being at rest, I don't mind this so much.

I have noticed it as well however I don't think it is wind related since Event blocks almost all of the wind. I believe what you felt is evaporation cooling. Turning liquid water to vapor takes a significant amount of energy. The vapor then quickly travels through the membrane. You felt the cooling effect of water being converted to vapor.

With a pack on I noticed I felt cooling just to the left and right of my backpack. The pack prevented event from breathing so the water wicked sideways until it could evaporate and pass through the fabrice. Later on that same hike I also noticed my pack was getting wet (I was using the rain jacket as a wind shirt, it didn't rain). Some vapor did manage to penetrate the fabric where the pack was and as a result the pack and the outside of my event jacket were moist. I never saw that with my Gortex Jacket.

Yeh I was on the top of the famously cold and windy Jay Peak, VT this past weekend with Event shell pants and Goretex pro shell jacket. Pants over R1 pants, jacket over cap4+R2. So very wind permeable insulating layers. I could easily feel the wind through the Event (or some sort of cooling) but not the goretex. Pros and cons.

After looking throught the responses I see I'm not alone in my experience with eVent in very windy conditions.

I think eVent lets more wind through than "regular" Gore-Tex. But maybe the most breathable GTX, which is the Pro Shell version would be similar to eVent.
Anybody have GTX Pro Shell?

My Ski Patrol parka is "regular" GTX and wind never gets through – but I do get clammy when working hard in that parka.

>> In any case I'll still use my REI eVent parka year around. I make it double as a wind shirt and it works well in that capacity. Even dedicated wind shirts seem to be more permeable than eVent.

“…I could easily feel the wind through the Event (or some sort of cooling) …”

I’m guessing that “some sort of cooling” is the issue, not airflow through the laminate.

From Mr. Nisley:
“Cubic feet per minute per square meter (CFM) is a measure of the wind resistance or air permeability of a fabric. The higher the CFM, the greater the volume of air passing through.

“Traditional barriers like H2NO, Gore-Tex, eVENT, Triple Point, Entrant, and other respectable waterproof breathable technologies all have a 0 CFM rating. If you are just sitting still or doing camp chores a 0 CFM garment will block all wind and keep you the warmest. Both eVENT and Gore-Tex Direct Venting achieve this with a pore size of about .2 microns.

“With the advent of soft shells and more breathable fabrics, the air permeability argument becomes complicated, sometimes heated. If you are backpacking, you can afford a bit of convective heat loss. You need more breathability to move the extra moisture you create through exertion. And a fabric with 0 CFM doesn’t provide it. Fabrics that measure as much as 5 CFM are still functionally windproof: that is, you don’t feel the breeze come through. And they afford much greater comfort with the high exertion rates during backpacking. Popular wind shirts, like the Patagonia Houdini, fall into this class as do the best soft shells. The average pore size for this class of fabrics is about 20 microns or 100x times larger than eVENT. Any larger pore size will result in more than 5 CFM. After 5 CFM you can start to feel the wind through the fabric.”

Not exactly your question.

I once tried a gaiter of eVent on one leg and one of Epic on the other. The breathable fabric was WAY more drafty than the
eVent. No great surprise, I sweated easily in the eVent gaiter first.

My shell is a Goretex Pro Shell (Arcteryx Theta AR) and I've yet to feel wind through it. The pic in my avatar is me wearing it on a trip with -5F (not windchill) and 75mph winds. That said, you can also see that i had it unzipped in that pic… ha. I do certainly use the pit zips on that jacket. I pretty much always have them unzipped between 1-3" and I'm fine while hiking, skiing, etc.

Greg, I'm sure you're right. Another factor that i had forgotten about is that my shell pants have full length zippers. They're welded, but i'm sure that's their weakest point.

Would a windshirt be more or less windproof?

I'm really surprised that wind can get through a wp/b layer.

> I don't think it is wind related since Event blocks almost all of the wind.
> I believe what you felt is evaporation cooling. Turning liquid water to vapor
> takes a significant amount of energy. The vapor then quickly travels through the
> membrane. You felt the cooling effect of water being converted to vapor.
Exactly.

A very simple test is to try to blow through the fabric. You will very quickly find that membrane fabrics do not let the wind through. But eVent does let water vapour through faster than trad Goretex. That is the whole idea, isn't it?

Cheers

I live in a very windy place and often wear my Event shell jacket for short walks where I don't get sweaty. It is very windproof and seems comparable to Gore-Tex in wind resistance. I think what you're seeing is more evaporative cooling with Event than with Goretex. This is what it is supposed to do and matches specs, but is sometimes a disadvantage.

"But eVent does let water vapour through faster than trad Goretex."

That's consistent with what Greg said, if eVent feels cooler its because of evaporative heat loss

So, if there's water there that can be evaporated, it should be. The solution is to not sweat. Don't wear too much clothing or slow down.

Or, maybe it's like the concept behind VBL clothing, if the humidity gets high, then you will stop sweating. But then everything inside the eVent will get damp which wouldn't be good.

I notice that my (uninsulated) eVent feels more "drafty" than anything else. Even when just standing around and not moving (eg, at the train station) it APPEARS that I can feel more air movement thought it even fully zipped up and I'm nowhere near hot.

I just keep an tiny packable (EB FA) windshell in the pocket, which I would have anyways. If it's raining and I'm getting too cold, the windshell goes on, either under or over depending on the situation. Terrible fashion but it works. :)

-mox

… I stand corrected. What I felt then likely was faster evaporative cooling than I do with traditional Gore-Tex shells. eVent truly does breathe very well and is "direct venting", not relying on absorption and wicking like traditional GTX.

BUT, either way I felt cooler in the eVent parka. I had Gore-Tex ski pants on and did not feel cooler on my legs.