Although the eVent vs Gore-tex post was recent, I feel it is of merit to show this video for the value of increasing awareness of how many more paddlers might be willing to wear dry tops and dry suits in warmer air temps with still dangerously cold water.
eVent is up to 300% more breathable. I am NOT promoting any company selling it, but this video does come from one seller. I have tried this product and find it to be MARKEDLY more breathable than my tried and true Kokatat drysuit. I have worn an eVent raincoat as a Sierra guide for 7 seasons and it is still working perfectly after quite allot of very hard use.
http://www.youtube.com/watch?v=yi0DaHQ5ro4&eurl=http%3A%2F%2Fwww%2Enrsweb%2Ecom%2Fshop%2FProduct%5FVideos%2Easp%3Fpfid%3D2584%26vid%3D9&feature=player_embedded
http://www.youtube.com/watch?v=6KeBwApMsjA&eurl=http%3A%2F%2Fwww%2Enrsweb%2Ecom%2Fshop%2FProduct%5FVideos%2Easp%3Fpfid%3D2584%26vid%3D96&feature=player_embedded
Impressive, but…
...they only showed half the story. It makes me wonder what would happen if they reversed the procedure and tested to see how much pressure it would take to force WATER through the two fabrics? Even their website doesn't talk about the waterproofness of their fabrics, just the breathability. I strongly suspect that you could spray any cotton/nylon/polyester fabric with Scotchguard and duplicate the eVent test.
To date at least, there has always been a trade-off of one for the other and manufacturers have to determine which is more important to them and decide where to draw the line. Gore has always made waterproofness their paramount parameter, which is why they have their garment certification program. They've also made highly breathable, but less than completely waterproof fabrics, Windstopper for example. I would really like to see an independent comparison of eVent and Gore fabrics on both parameters. THAT would tell the whole story.
For the record, I have no more connection with Gore than you do with eVent, I'm just a satisfied customer. If eVent can provide similar levels of waterproofness to Gore-Tex along with it's better breathability AND comparably durability, I'd buy it in a heartbeat.
well,
from that segment eVent resists at least 2 inch column, equivalent to roughly 1m/s water load.
What do you think should the pressure differential be to represent real life usage?
Might be fun to try, but eVent is impossible to find for purchase.
Better mouse trap, for safety sake
PTFE membrane is same for eVent and Gore-tex. Only Gore could not solve the oil loving properties of PTFE and had to add a PU layer to prevent contamination. The PFTE was mainly kept because it allowed the PU layer which is fragile to be much thinner if layered with the PTFE. This allowed toe significant decrease in breathability to be held to a lower number even though they lost most of their original capacity.
The eVent company found a way to not have the PTFE get contaminated. The PTFE membrane in BOTH fabrics will leak, that is allow water through if it gets contaminated. IF not contaminated, the holes in PTFE are too small to allow water through, only vapor. So, yes eVent and Gore will both leak water through from outside to inside
BUT not under PRESSURE, only by contamination. The eVEnt is superior to Gore in NOT getting contaminated. It is not perfect. If you really mess with it, do not replace the DWR finnish on outside never clean it eventually it could get contaminated. But even so, that is fixable.
I have a Integral Designs eVEnt backpacking rainjacket I have used as a mountain guide under backpacks for years and with a modicum of care it has been flawless. I don’t have the scientific study showing eVent long term use though.
We are all right to be wary of manufacturer claims and to adopt new things slowly. I applaud a wary and skeptical eye. And like a new mouse trap, if the old one works well don’t go for a new one. But this product really is a dramatic and significant improvement that just might get more of us wearing safe clothing.
For this motivation alone I posted this. : > )
Anecdotal evidence is fine…
...as far as it goes and I respect your opinion and experience. However, I want to see hard numbers, so I can judge objectively and see exactly what trade-offs are involved. I'm always very leery of companies who don't provide that kind of information, as it usually means that they have something to hide. If eVent is truly a breakthrough, they should publish laboratory test results comparing it to other fabrics. If you know of any such tests, please post a link here, as I'd be very interested in seeing the results.
One thing I'd like to point out is that safety is relative. If you're talking about high exertion in the mountains in winter where staying dry is critical to staying warm that's one thing. Providing immersion protection in cold water is another matter, though obviously related.
Not sure
I don’t have the figures handy, but I know that it’s MUCH higher than that for Gore-Tex. IIRC, Gore-Tex is essentially as waterproof as non-breathable polyurethane-coated fabrics. Their standard seems to be that degree of waterproofness with whatever degree of breathability that they can achieve. Notice that over the years, their work seems to have been always about making each generation of their fabrics more breathable without compromising waterproofness.
Perhaps they’ve set the waterproofness bar higher than necessary, I really don’t know.
i agree
Yes, we are of like minds. I do believe I saw that evidence in a scientific paper. I am like you tough minded and properly skeptical. And the kind of science that tests in real world conditions is what is most needed too.
If I can find it, I will post it here. It appears to me, not a chemist, that the crux of this is just how oleophobic the eVent is actually over time. It is fantastic initially, that has been shown scientifically. We have seen that Gore could not solve this, i.e., they had to abandon this method and add the PU.
Note B that Gore has had to use PU they did not want to. PU is very very fragile and does not allow vapor through. So Gore had to make the PU very very thin or lose all ability to breathe at all. They solved this by keeping the PTFE layer as protection as it is stretchable. They did not need the PU to make the pressure of waterproofness higher. PTFE when not contaminated has holes too small to allow any water through.
Both fabrics, Gore and eVent are fragile and need protection by layering and sandwiching them. Both can be compromised.
As my skeptical mind sees it Gore and Kokatat have found a way to make a durable product that they back. This is a big plus.
NRS and others using eVent must show us the same dedication to real world manufacture and back it up. If so though, this could be a genuine break through product.
Researched advantages further
EjVents has two more advantages. One, it is more effective at all humidity levels. Two it can be cleaned easily with regular soap, unlike Gore tex.
eVENT’s membrane structure is important in two ways. First, molecules in their gaseous state (including perspiration vapor) can pass through the pore channels between the membrane’s fibers, a process that is capable of moving significantly higher fluxes of moisture than what is possible for by a solid layer of PU (as in Gore-Tex).
Second, and more important, eVENT passes moisture equally well at both low and high humidity levels, evidenced by the independence of eVENT’s moisture transmission rate on the humidity level (see Figure 1). At a 70% mean humidity level, eVENT transports moisture about 30% faster than XCR and about 70% faster than standard Gore-Tex and the best PU membranes. But at a 30% mean humidity level, eVENT transports moisture about 200% faster than XCR and about 250% faster than standard Gore-Tex and the best PU membranes.
Why is faster moisture transport at low humidity important?
If moisture can be moved out of a clothing system soon after humidity begins to build (low humidity levels), the risk of moisture vapor accumulation, condensation, and wetting of clothing worn underneath the shell is minimized. The ability of a shell fabric to pass moisture at a high rate at low humidity levels, then, increases the time at which the shell can be worn during periods of moderate exertion levels.
But now consider sustained or higher exertion levels, resulting in perspiration that overwhelms the ability of a garment to breathe, and your clothing starts to get wet from the accumulation of perspiration. Since eVENT moved moisture faster and started moving it earlier, you’ll maintain drier clothing longer than if you wore a PU garment. More important, when your exertion level lowers and the internal humidity level in the garment decreases, eVENT will continue to move moisture at a higher rate than PU, which ultimately contributes to faster drying times for your clothing.
One final advantage for eVENT garments is that they are easy to clean. Gore recommends that you wash Gore-Tex with special (and expensive) cleaning products (if you don’t, you run the risk of reducing the hydrophilicity of the PU membrane - which could compromise its ability to transport moisture). You can wash eVENT pretty much the same way you wash your regular clothes - use a mild liquid soap (detergent-free) and a 2x rinse cycle.
I have an eVent top, and even with
no gaskets at the wrists or neck (Velcro closures), it is too hot to wear in summer conditions over cold water. And, I can detect some accumulation of moisture inside. It’s the best breathing top I have, but I don’t think unrealistic expectations should be set. There may be some summer conditions where an eVent, drytop or drysuit would be too hot, even though one was paddling over cold water. Rolling helps in whitewater, but I don’t know if I would want to roll that often in a loaded touring kayak.
yes agree
Yes, any shell that is windproof will stop evaporative cooling as a mode of cooling that is effective, like how how we get on a 95% humidity day even with a breeze. I agree with you totally.
What I am posting for are those conditions where the water is still killingly cold so we must as you say roll some to stay cool. Yes, no magic bullet. Still this thing breathes so much better it is a factor in being able to wear the dry suit or jacket and knowing us humans it might help, that is all.
Link to scientific review eVent and Gore
Here is the link to the research on eVent and Gore-tex, a definitive scientific review.
Link for paper:
http://www.backpackinglight.com/cgi-bin/backpackinglight/00316.html
Link showing rate of breatheability for various fabrics. Note how little Gore-tex XCR is improved over earlier Gore product despite manufacturer claims
http://cache.backpackinglight.com/backpackinglight/images/wpb2004_figure1.jpg
Again, there is no waterproofness data
The fabrics in the graph that have similar breathability to eVent (Entrant and Schoeller) are not known for being especially waterproof.
I have no doubt that eVent is extremely breathable and I don't need more evidence of that. While breathability is important, it's not the be-all and end-all of fabric properties, otherwise we'd all be wearing cotton all the time. What I want to see is data on how waterproof eVent is compared to other w/b fabrics. Is there anything about that in the article? I can't see paying for it if it doesn't contain the data I'm interested in.
overall quality
With the NRS eVent drysuit in mind, when choosing a high cost garment, the waterproof-breathable advantage is only one factor to consider. The overall manufacturing quality and components such as zippers, latex gaskets, stitching, and accurate sizing proportions, along with the warranty are equally important for longevity and durability. Even with Gortex vs Event used, I might prefer the Kokatat products until more history on the NRS suit accumulates. Now if Kokatat eventually uses eVent with a strong warranty, it might be a no-brainer.
all valid points
Hey guys, I am not a first adopter either. Just saying bears watching. The initial data I saw, and dang cannot find right now, shows eVent to be just as waterproof as Gore and more durable.
But yes, we have not seen it out for long enough to know real world results in a drysuit.
And, yes, I am staying with Kokatat until I see all the other stuff done well also.
B, the Schoeller and other stuff is NOT listed as waterproof. They were just showing how breatheable eVent is considering these fabrics are touted as highly breatheable and not even as water or windproof.
I am just trying as I get older to stay open to new things and not become what is called a Retro Grouch!
Too late!
Just kidding.
Gore warrants their fabric to be waterproof and breathable. That is why Kokatat is able to provide a such a strong warranty on their GoreTex products. When the makers of eVent fabrics offer the same lifetime fabric warranty to manufacturers as Gore does, eVent will become a significant competitor (and the price of garments will likely double as well).
For now, and based on previous experience, I have no interest in anything other than the Kokatat/Gore warranty and Kokatat’s customer service for such a critical piece of gear.
I have been using eVent fabric compression dry bags for a couple of years and like them a lot. So far no issues with them being waterproof, but they are also not submerged and stressed lake a drysuit is.
Supposedly eVent has been extensively tested at the US Army’s Soldier Systems Center, in Natick, Massachusetts. It would be nice to see the results of these tests. I would think that if eVent is a superior product to GoreTex for being waterproof/breathable/durable the next generation of military drysuits will be using that fabric no matter who has the contract to manufacture them.
http://nsc.natick.army.mil/media/fact/ss&t/Selectively_Permeable.PDF
Best,
~wetzool
Not connected to eVent manuf/dealer…
…But, temperature inside may be a distinct issue, but when breatheability levels are high…a little water entering from outside doesn’t stay on your skin…as opposed to perspiration not wicked off, a very distinct difference.
Martin and Wetzool GE advances eVent
Martin, GE is trying advance eVent along with Armed Forces. Dig Wetzool no end to things he knows, oh my god!
eVent® fabrics Introduces New Membrane Treatment
For Immediate Release
Verde PR
Kristin Carpenter-Ogden
970.259.3555
kco@verdepr.com
Kansas City, Mo., March 16th, 2007 — Continually at the forefront of innovation and technology, eVent® fabrics introduces a new supercritical gas-based membrane treatment that further eliminates the need for a PU (polyurethane) coating while increasing performance of its waterproof breathable membranes.
The new treatment improves on eVent fabric’s durability while preserving its inherent open-pore structure and Direct Venting™ capacities. Additionally, the new treatment optimizes the membrane’s performance at cold temperatures.
Forerunners rely on hydrophilic (water-loving) PU membranes or an added PU coating. Adding PU makes a membrane oleophobic, or oil repellant. While it helps to block oils, the added PU layer also reduces the membrane’s capability to move moisture because it must become wet inside for it to transport moisture.
The eVent fabrics membrane has always been completely PU free, making it the only Direct Venting™ membrane among “breathable” peers.
Instead of coating the membrane with PU, eVent fabrics are treated with a patented hydrophobic polymer to achieve oleophobic properties. Utilizing the vast resources of eVent fabric’s parent company, General Electric, a new process of application is announced. eVent fabric’s oleophobic polymer is applied by means of a supercritical gas treatment, eliminating the use of solvents during the production process
This new technology enables both the gas and polymer to completely penetrate the pores of the eVent fabrics membrane, encapsulating each and every fibril during treatment.
This new process leaves no residue and treats the membrane on a structural level, retaining and enhancing the precious membrane properties. The process of application is patented and the polymer is patented pending.
The switch to eVent fabric’s new membrane treatment will take place gradually throughout 2007, and will be seen in the market by 2008.
Army eVent test results
Here is the link to the study
http://www.shelby.fi/tips/breathability.pdf
The US Army’s Natick tests of waterproof-breathable laminates reported that eVENT fabric, a patented ePTFE-based membrane produced and marketed by BHA Technologies, Inc. proved to be the most breathable of all materials tested, averaging twice the breathability of its closest competitor. Testing included the likes of Gore-Tex XCR®, Sympatex®, and various other waterproof-breathable fabrics. “As a premium, technical brand, ground sought to utilize today’s top technologies to create our high-end apparel line,” stated ground’s CEO, Tucker Hacking. “After reviewing the government’s Natick testing we were sold on using eVENT fabric to achieve the technical pinnacle in our soft shell, hard shell and down product categories.”
I’ll wait for the Navy testing. 
NM
Don’t get me wrong…
…if eVent is truly a breakthrough, I’d adopt it in a heartbeat. I’m just not going to do so until I have the whole story.