eVent or Epic: Which is more breathable?

Bryan,

I don’t know the answer beyond any reasonable doubt. I can only “parrot” back to you what i’ve read.

I had thought Epic was more breathable and i’ve read that it is, but only other more knowledgeable people’s opinions. I’ve read others saying eVent is more breathable.

Also, an email i received a couple of years ago from Dr. J, as well as some posts on these Forums, indicated that Epic has a problem with breathability at the point of freezing and for some degrees below freezing. If i understood his explanation correctly, water vapor freezes in the fabric and effectively stops any further transmission of water vapor through the Epic fabric.

Now this discussion was about single-wall Epic tents. How it applies in practice to Epic fabric shelled sleeping bags and garments was not the point of the discussion and so it might be unwarranted to extrapolate. I could envision the phenomenon occurring in both of these too, but to what degree is another question.

If i were in your position, i would just call or email FF and ask them. I would hope that they would know the answer and be able to express it authoritatively.

Sorry i can’t be more help.

for tents that might be true, but I suspect that the heat from your body, because of its proximity to the event shell, would be sufficient to prevent moisture from freezing in the fabric under normal winter conditions.

You know Bob, that thought crossed my mind, but what happens if it’s very cold inside of the shelter, couldn’t it be 30F-32F at the fabric interface between the outer portion of the insulation and the ambient air? And, it could easily be 30F-32F OAT when wearing an insulated Epic shelled garment.

The temp gradient is always going to go from the OAT, or ambient temp if inside of a shelter, to whatever the temp is at your skin. It’s the slope of the temp gradient that will be either steeper or shallower depending upon the delta-T between those two temps. As such, i could envision the freezing point being anywhere from the outside of the shell fabric, to on the inside of the shell fabric, to buried somewhere within inches of insulation, to even right next the skin, depending upon the delta-T and the amount (and effectiveness) of the insulation.

But still, i don’t know. Guess we’ll have to wait for BPL to reveal the precise workings of this phenonmenon and when and to what they apply.

Oh, i’ll have to go back and check and make sure that i said it was Epic fabric and not mistyped it as eVent. But either way, i get your point.

Bryan-

A couple of comments:

1) Several lab tests show eVent to be more breathable than EPIC. But…

2) EPIC has greater air permeability than eVent. So in windy conditions, it *may* have better breathability than eVent. (Just a hunch at this point.)

3) The freezing problem where ice forms in the EPIC pores and inhibits breathability was observed in bivy sacks. It’s not really relevant to a down garment where much of the condensation occurs in the down instead of on the shell fabric.

4) Currently available eVent fabrics are heavier than the lightest EPIC ones.

5) Even though eVent fabric is waterproof, unless the jacket is fully seam taped, an eVent-shelled down jacket will not be waterproof due to the exposed stitching.

6) Both shells would be excellent for a bomber down jacket. But in your situation, I personally would choose the EPIC shell for it’s lighter weight, softer hand, and increased compressibility.

7) Take a look at Alan Dixon’s article on fabric performance for an excellent reference on this topic.

Michael,

Many thanks for the authoritative, informative Post. You sure cleared up a number of points for me.

> 1) Several lab tests show eVent to be more breathable than EPIC. But…
The trouble is, as we know from other manufactures of membrane fabrics, when the vendor does the test you can be reasonably sure the conditions favour their product over the opposition.

There are other factors, and air movement is one as Mike says. EPIC will allow some air movement; eVent won’t.

When I was shopping for a new rain jacket last year, I bought 3 jackets made of Gore Tex Paclite, Epic and Event. I tested their breathability by carring a loaded pack up hill on 3 different days. The Event won hands down. The other 2 were not even close.

In my recent search for a tent, I came across some URL’s with more info on the Epic:
http://www.nextec.com/thetech/
http://www.titaniumgoat.com/DWR.html

Larry,

Many thanks for sharing your valuable real world experience. Appreciate it.

Oh,… BTW, i too find the ID eVent shell works very well when exerting myself (up to a point, but it’s quite a “point”).

I also love the Wild Things Epic windshirt, though i actually sweat soaked it once (not paying attention; more interested in ascending to the “goal”).

I am not entirely sure what previous posters meant by “air movement” affecting breathability in EPIC, but I’m pretty sure this also applies to eVENT. I recently bought an eVENT rain jacket and I have noticed that although it is 100% waterproof it isn’t 100% windproof. When hiking two weeks ago in West Virgina I could feel a “slight” breeze coming through the fabric whenever I was exposed to a stiff wind. Although this certainly isn’t a scientific experiment, I definitely believe that there is significant “air movenment” in both directions through eVENT and not just one-way “moisture movement”. BTW I’ve found eVENT to be more breathable than any other WB membrane I’ve used before (Triple Point Ceramic, Gore-Tex, H2No).

I have never used eVENT, only Gore Tex. And I have only recently purchased an EPIC covered Primaloft Belay parka, that I havent gotten a chance to test out yet. However, I have read a lot about both EPIC and eVENT and from my reading, I would say EPIC is more breathable. eVENT is a full blown waterproof breathable membrane material, marketed as a “more breathable than Gore Tex” raingear.

On the other hand, EPIC is not being marketed as a full blown piece of raingear, it is being marketed as a softshell material. It is marketed as being windproof and highly water resistant…as “almost” as good as full blown raingear. And its marketed as very breathable.

eVENT= truly waterproof but more breathable than Gore Tex.

eVENT is being marketed as a “hard shell”

EPIC= windproof, “water repellant” and very breathable and the coating doesnt wash off because there is no coating.

EPIC is being marketed as a “soft shell”

(I think these terms soft shell, hard shell and “high loft are stupid terms BTW)

Going by what Ive read, EPIC has got to be more breathable than eVENT or any other truly waterproof but breathable material.

My daughter is considering a lightweight down jacket for general use. She would like some waterproofness, but, of course, understands it needs to be breathable otherwise the down will become compromised .

She’s considering a Feathered Friends Hyperion with a shell made from EPIC and a shell made from eVent. Your thoughts?

Is she going to be in a cold by dry climate? I hope so, as that is what goose down insulation is intended for. Extreme cold dry climates.

If she isnt going to be in a cold dry climate and only needs a lightweight jacket, why not consider a synthetic fill jacket. Filled with Primaloft or Polarguard 3D or PolarGuard Delta? Primaloft is as light as down, as compressible as down but is much easier to launder, cheaper and IMO, just plain better except for extreme cold dry weather conditions.

Vlad

Thanks to all for your input.

Vlad, yes I concur that down may not be the best option (I use a Patagonia Polarguard Delta vest for most of my “general use”) for my daughter’s general use (mostly school, etc.) coat, but she loves the “coziness” of the down, and it is her decision (despite, or inspite of my counsel).

We’ve made progress at least, in getting her to consider a down “sweater” (or light weight version) rather than a down jacket. But, even with that, we faced with shell issues, precip, etc.

Cheers,

Hi

I spoke to a designer for Outdoor Research who thought Epic was over hyped.

He said that the windproofing layer that fills the gaps in the Epic weave was made from Polyeurathane and therefore had all the water absorbing & breathability inhibiting problems associated with PU & GoreTex etc.

This makes me think why not create an Epic/eVent hybrid. Same principle as Epic but fill the gaps with eVent’s membrane material. So no heavy 2.5 / 3 layer fabrics & no PU water absorption problems. And last but not least no annoying DWR problems because of Epic being a siliconized fiber.

Anyone else ever thought of doing that?

If I had the money, and wanted to protect my down jackets, I think eVENT is a no brainer.

As others have noted, eVENT tests as more breathable than EPIC in the lab. My field experiences has also found eVENT to be more breathable. Some folks mentioned that the better air permeability of EPIC should close the gap if not put EPIC on top. I have not found this to be the case. The air permeability of EPIC did not seem significantly different from eVENT in the field.

There are a few reasons to use EPIC over eVENT. It’s often cheaper. It’s available in a number of weights which are lighter and more compact than the lightest forms of eVENT, EPIC absorbs very little water, and the DWR is very durable and easy to refresh.

–Mark

Again the breathability varies as to which fabric
the Epic treatment is applied. Some versions of
Epic feel like wearing cotton twill and allow a lot
more venting through the fabric than eVent, but
I agree that the Epic shell on a down jacket would
be a tighter weave and may be less breathable than
eVent, certainly less waterproof. At some point,
with the thickest insulation, say the polar parkas,
the condensation will occur on any outer layer, and
somewhat defeat the reasons for having a waterproof layer. Parkas of this type traditionally have a free hanging outer shell so frost
that accumulates under it can fall out the bottom of
the garment.

Mark – how would you recommend refreshing the DWR on Epic?

The manufacturer of Epic fabric suggests just washing it to remove dirt, oil, etc.

This is what is meant by “refreshing” it. It requires no DWR treatment.

FYI: As David mentions, there are a LOT of different Epics and eVENT fabrics (similar to my recent post about all the different Pertex’s.) Knowing, if possible-good luck, which one by weight/version, base fabric construction plus any coating,calendering, year of Mfgr, etc. would have to be know to compare apples to apples.
In our fabric and product descriptions we will always try to be as specific as possible and hope that may start a trend; at least with smaller SUL companies. I’m sure the big mfgrs don’t want to confuse their customers with TOO MUCH INFO!

> I spoke to a designer for Outdoor Research who thought Epic was over hyped.
I take it they don’t use EPIC? If not, the rest of what he said follows, in a manner of speaking.

> He said that the windproofing layer that fills the gaps in the Epic weave was made from Polyeurathane and therefore had all the water absorbing & breathability inhibiting problems associated with PU & GoreTex etc.

What utter crap. Either you have *totally* misunderstood what he was saying (this I doubt) or HE had no idea of what he was talking about.

First of all, EPIC encapsulates the fibres with a silicone polymer. As far as I know, they do not attempt to fill the gaps afterwards: their game is encapsulating the fibres and then relying on surface tension. Yes, a little gap-filling goes on with the silicone polymer – but not much.

Second, it is extremely difficult to get PU and silicone polymers to stick to each other. I doubt anyone would try to do this. Trying to get a PU membrane or fill onto silicone-coated fibres is silly.

I have tested some lightweight EPIC fabrics (eg Malibu) for airflow, and they do pass air.

Trying to imply that EPIC fabrics are just the same as Goretex is farcical. In fact, they are almost opposites.

No, I have no vested interest in ANY of these technologies. I have fabric samples from them all and I have made and tested gear using those fabrics – myself. My opinions are based on what the vendors have said about their OWN technologies and on MY testing.

Be very wary when a company rep starts to bad-mouth the opposition’s products. In my experience, the ones who are willing to do this are the ones with the least knowledge of all.

Hey Roger

I apologize for my gross inaccuracies regarding Epic. I know OR don’t use Epic but I did talk to them about it & he did talk about gaps being filled. It’s possible the designer said ‘Polymer’ and I wrongly remembered ‘Polyurethane’. And therefore comparisons with PU membranes are nonsense as you say.

Oops! Sorry.

Moving swiftly on to more relevant questions again:

As eVent is a membrane attached to an outer layer with a DWR coating which will wear out (sooner than later in my experience) then in practice you’ll have a eVent fabric which will wet out in the rain. My question is does having a wet through outer layer affect vapor transfer enough that Epic becomes a better choice? Also does Epic leak much under heavy rain?

I know you can reproof fabrics but I’ve never had much success. The reproofing has always worn off in about a week.

Sab

Epic definitely will leak under heavy rain. Even under a light rain where the rain pressure is being repelled, Epic will leak under the pressure of pack straps once water accumulates there. It seems to work well in single wall tents as long as you don’t touch the tent wall and as long as you seal the tent well. I’m not aware of any sealed Epic jackets, but it is possible to reduce seam intrusion by sealing with silicone on the inside. Silicone on the outside seals better, but for some reason while I don’t mind silicone outside a $300 tent, it bothers me to goober up a $50 jacket.

I’ve never let my DWR get shot on Goretex so I can’t speak from experience, but it seems to me I’ve read that wetted out Goretex face fabrics prevent the material from breathing very well.

Epic is a good choice for down garments where you don’t want to mess up the down by spraying on or washing in a dwr. Both Epic and down benefit from washing with a clean rinsing soap like Atsko Sportwash.

The best re-proofing I’ve found is 303 Protectant but it stinks and isn’t solvent free like Nikwax or some of the others. For ease of use I use wash-in Nikwax more frequently because the solvent based products are more of a hassle to use. It doesn’t last long but after a trip I just wash and retreat so it’s ready to go. Most DWRs seems to benefit from a tumble drying to melt and spread the coating over the fibers. When your DWR seems shot try drying first and that may be enough to revive it for a while.