Home › Forums › Campfire › Editor’s Roundtable › Field Testing Air Permeable Waterproof-Breathable Fabric Technologies – Part 2: Are There Detectable Differences Under Real World Backpacking Conditions?
Oct 25, 2011 at 1:27 pm #1281108
@addiebedfordLocale: MontanaOct 25, 2011 at 3:04 pm #1794942
@davecLocale: Crown of the Continent
That is some seriously dedicated hiking.
I disagree on the Spektr being under sized. The sleeves and torso are actually longer than almost any other comparable jacket (all other things being equal). I'd call the fit actually fitted. They do need to get rid of that goofy lumbar cinch cord.Oct 25, 2011 at 7:14 pm #1795037
@richard295Locale: San Francisco Bay Area
Excellent! Thank you for the hard work and valuable data provided in this article.
I am having difficulty easily discerning which line is for which jacket for similar colors. Please add different line patterns for similar line colors to facilitate interpretation.Oct 25, 2011 at 9:38 pm #1795086
@brendansLocale: Fruita CO
Excellent report. I generally hate wearing rain shells and only take one when I know I'm going to be hiking in sustained rain in cold weather (usually I'd rather hike in a windshirt with good DWR that absorbs minimal water). For me, this article confirms that fabrics such as event are not worth the extra $ and that the biggest priorities are fit (especially hood) and that the jacket is light and compact enough that it doesn't seem like too much of a burden to carry (9oz max).Oct 25, 2011 at 9:51 pm #1795091
@verberLocale: San Francisco Bay Area
Thanks will… this is excellent. This is exactly the sort of report I have been hoping BPL would do. Reminds me of the 2001? which looked at moisture accumulation. Just the sort of info glossy from manufactures don't provide, and where the normal person doesn't have access to enough variance to do any comparisons. This is VERY valuable. Thank you.
I also had trouble telling which lines which which. You could do the patterns recommended by Richard… but being a data guy I would say "how's about posting the data via google doc, csv, etc so people can play with the graphs."
I appreciate you indicating that none of the materials are fully up to the task. I read so many people say "X is so breathable" where my experience is nothing is good enough when doing a hard push. I haven't tried all of these jackets/materials, but what I have used match what you describe. I understand why you might have expected PowerShield to function better than your test indicates, but that completely matched my experience using PowerShield in the field. I don't get the membrane soft shells at all. In my experience they aren't as comfortable, breathable, or waterproof as eVENT. The only think that seems to best eVENT are stretch woven which are MUCH less waterproof.
The one material/jacket I would love to see added to this would the the lightest driducks or or rainshield 02 which gives surprisingly good performance, especially in view of cost.
–MarkOct 25, 2011 at 10:32 pm #1795100
one thing that i think would be most interesting to test it the OR torso flow ventilation system … its basically 2 way zippers down the side of the jackets …
IME .. it provides extreme ventilation, and if yr wearing synth layers, the occasional rain that comes doesnt matter too much … also a double zipper allows you to leave the bottom of yr front zip open while having the top closed
edit … does anyone else think it quite hilarious that a $129 backcountry brand (stoic) jacket outperformed most other yuppie brand jackets that cost double the price ;)Oct 26, 2011 at 12:47 am #1795105
@trevor83Locale: ATL -- Zurich -- SF Bay Area
Will, that was awesome. Thank you very much for this very insightful article.Oct 26, 2011 at 1:58 am #1795113
Inaki Diaz de EturaParticipant
@inaki-1Locale: Iberia highlands
Invaluable data. Despite the obvious difficulties to keep the testing conditions coherent, this is more revealing than anything I've seen before in a field where most of the available data is hype.
To further overwhelm Will, I not only second the proposal to include some Propore item but also two rather extreme shell test cases: a woven windshirt (no membrane) and a strictly non-breathable top. Those two benchmarks would adequately frame what WPBs really offer.Oct 26, 2011 at 5:33 am #1795133
holy friggin cow, this is the most detailed WPB test I've ever seen… Will, thanks for detailed report! Awesome!
edit: I suspect Spektr fares well because it utilizes roll closures instead of zipper. Won't be surprised if it gets Highly Recommended… And agreed with above advices, where is THE driducks test…Oct 26, 2011 at 7:12 am #1795152
Big thanks for the material.
Now some thoughts and questions (in order of appearance in my mind):
+1 for trouble of reading graphs and vote for google docs.
– GoreTex membranes are not air permeable.
– I think the inner liner of Rab and TNF jackets might be a little warmer than the other jackets liners. So it helps to generate more heat inside the jacket and correspondingly more humidity. It can be corrected by the thickness of base layer for example.
– May be the effectiveness of front zip opening was increased because humidity sensor was near the front zip? If it would be near pocket or underarm area, then we might get different results.
-What is the technology behind Stoic Vaporshell and Breeze Dry-Tec?
-I think that control of heart rate during this test series (to make sure it is constant) could help to make conditions more equal.
-And most important thing. It is simple – we need rain gear when it is raining. When it is not raining we can use windshirt and thats all. So for me it would be more interesting to test this rain jackets when there is 100% humidity outside and its rather cold (to make sure we dont overheat to much during testing). Then we can find an answer what type of membrane laminates is more comfortable. And i assume it would be the membrane with high air permeability and that gets more score on the A1 breathability test.Oct 26, 2011 at 8:29 am #1795174
One thing not mentioned: with the inside temperature 20-25 degrees F warmer than ambient and the inside relative humidity of 80% or more, it is inevitable that sweat will condense on the inside of the shell (which is cooled by the outside ambient temp). Some mistakenly think this condensation comes from rain leaking in.Oct 26, 2011 at 8:39 am #1795178
@mikefaedundeeLocale: Under a bush in Scotland
Thanks for all the work, but it seems strange not to test rain gear in the rain!
The ventilation issue isn't really relevant imo. If it's raining, all the zips are closed. If it was dry enough to wear a jacket with the front unzipped, i wouldn't be wearing the jacket.Oct 26, 2011 at 8:42 am #1795183
@clbowdenLocale: Berkeley Hills
Verber wrote: The one material/jacket I would love to see added to this would the the lightest driducks or or rainshield 02 which gives surprisingly good performance, especially in view of cost.
+1Oct 26, 2011 at 8:51 am #1795186
Thanks Will for taking one for the team! Subjecting yourself to uphill hikes with not-so-breathable jackets.
One note: the MontBell Thunderhead uses Gore-Tex PacLite Stretch on the arms and elbows (according to their website).
Great report overall. Glad you were able to get so many jackets. I wonder how Gelanots would have compared. It is a four-way stretch WP/B fabric used by OMM, Milo and a few other companies around the world.Oct 26, 2011 at 8:51 am #1795188
Martin RJ CarpenterMember
Think there's a good explanation for your confusion.
Notice that he purposefully chose for very still conditions so basically no wind on the undulating walk and 2-10mph for hilly one being notable. Amazed he could get enough days like that actually, but clearly common enough where the testing was conducted!
Now compare the results for Powershield Pro/Neo shell on the two hikes. A very obvious difference, especially for PPro. Or even actually I suspect the Felstrum (negatively), although not sure if thats entirely clear.
On reflection thats very logical, because even PPro doesn't have a *huge* level of air permeability overall. And so other factors are relevant in very still conditions, but once the wind gets up it turns much more important.
(Suspect it actually partially explains the slightly mixed empirical reviews of PPro this.).
So do you often get still, rainy conditions? I'd say not so much in the UK, but it might very well vary :)Oct 26, 2011 at 9:11 am #1795199
Inaki Diaz de EturaParticipant
@inaki-1Locale: Iberia highlands
> If it was dry enough to wear a jacket with the front unzipped, i wouldn't be wearing the jacket
there actually is a practical application for this in the rain: a WP top plus an umbrella. It's a very versatile combo that I usually use in the long-ish hikes. The combination is also a powerful one: the umbrella allows great ventilation through the head and torso, the latter by partially unzipping the front. You still have a rain top for the arms and for full coverage when the umbrella is not a good idea.Oct 26, 2011 at 10:14 am #1795217
Will – Pretty awesome testing, nice work. As you pointed out, it's really difficult to test these fabrics under controlled conditions, but even so I think there is a very obvious take-away from this article: the marketing departments at these manufacturers have gone wild in their descriptions of this technology.
A few other points:
1- So WP/B fabrics aren't really that breathable…I think we all knew that. But they are also not very waterproof. Their waterproofness depends on the performance of their DWR, which is easily degraded by dirt, abrasion and body oils. Once the DWR craps out, the exterior layer wets out and the equilibrium process begins working in reverse: it's more humid outside the jacket (because the exterior fabric is saturated with moisture) than inside, so water starts moving inwards. Great, now you're wet from the inside and the outside.
2- The marketing pitch for WP/B fabrics hinges on a consumer's belief that they can actually stay dry when it's wet outside. My experience is that this is flawed expectation. The outdoors has no environmental controls like we are accustomed to in our modern lives: when it's cold, we turn up the heat; when it's hot, we turn on the A/C; when it's raining, we go inside; when it's muddy, we keep to pavement and leave our shoes in the mud room. Backpackers need to get over this idea that you can be immune from your environment — when it's wet, you should expect to get wet, because you will. It's much more fruitful to focus your attention on how you can minimize the effects of being wet.Oct 26, 2011 at 10:39 am #1795225
Excellent post Andrew!
I would also add that in my experience, high pressure rain can simply overwhelm the DWR at a point and time even without the 'wearing off' of the DWR over time.Oct 26, 2011 at 10:46 am #1795230
@james-cowderyLocale: Central Florida
As usual you hammer the subject with lots of data.
I agree with Inaki. I think running the same test with a completely non breathable top might show if there is a significant difference between a complete vapor barrier and an expensive breathable jacket. Would the results be significant enough to justify the added cost?Oct 26, 2011 at 11:21 am #1795236
@fluffinreach-comLocale: no. california
" Backpackers need to get over this idea that you can be immune from your environment — when it's wet, you should expect to get wet, because you will. It's much more fruitful to focus your attention on how you can minimize the effects of being wet."
you see, one can even tell the time by looking at the clouds. for instance, if it is raining, it is then time to get wet.
this is why they make wool.
or, if it's Really wet, polarstretch.
one will go a lot farther forward following andrew's advice than endlessly buying new parkas.
all that said. Great Test !
and, as a lot of things put on 2 dimensional digital graphs, in an extremely multi dimensional world and analog'ish world, it ain't going to give the whole answer.
case in point, i know for a fact that i can/will/do wear my e-vent parka a vastly lot more than i ever did my goretex ones, and that it runs dryer over a wider range of conditions than the graphs might indicate. and as indicated in andrew's insightful comments, i suspect sometimes the stuff leaks backwards.
once i found e-vent, i consider the fabric issue to be closed as far as me personally. it's good enough that any improvement is not going to increase my range or make a better experience. maybe yours, but not mine.
nice test though ! i like the comparitive condensation meters. if only it was as easy as wearing a different sock on each foot ….Oct 26, 2011 at 12:20 pm #1795252
@christownsendLocale: Cairngorms National Park
Good test Will. I've not tried all these jackets but I have been using the Rab Neo Stretch since last February, when I used it on a wet two week Southern Upland Way hike, and two Active Shell jackets, the Berghaus Velum and Haglofs Endo, over the summer and autumn, which have both been wet here in the Scottish Highlands. I judge waterproof jackets on how comfortable they are when worn all day, as is not uncommon here. On backpacking trips they are often worn all day every day. The wet, windy and humid Scottish weather makes this a tough place for rain gear. The key is keeping comfortable, which means just warm enough and not too damp. Nothing I've used keeps me dry when moving but some fabrics are far better than others (and of course the clothing you wear underneath makes a big difference too – many people wear too much and then sweat, producing much condensation – that's why I said "just warm enough"). Without doing a direct comparative test like Will's I've found the least condensation in Neoshell and Active Shell garments, with eVent not far behind. All three also dry out from inside more quickly than alternatives. I can get quite damp from condensation in any of them when working hard however. But condensation is warm and rain is cold so the first is preferable.
All that said, when it's cold enough (below 40F for me) Paramo performs better than anything else.Oct 26, 2011 at 12:28 pm #1795260
@umnakLocale: Southeast Alaska
Interesting and informative test on the one topic that I really struggle with; trying to stay dry in the rain.
Andrew Skurka nails it with his comment about accepting the rain. I've come to learn that if it going to be p*ss rain here, like it is from September to December I either wear non breathable Helly Hansen and sweat, or get by with an OR gore-tex pro jacket with the zipper system that Eric Chan illustrated above.Oct 26, 2011 at 12:31 pm #1795262
@dwambaughLocale: Pacific Northwest
Another excellent test of equipment with real data to compare. I'm glad to see the issue of how a backpack effects rain gear ventilation covered.
The side vents on the OR gear make a lot of sense. With just the front hem free, it allows air circulation between top and bottom. I rarely trap my rain shell completely under my belt, with the front draped up and over for more air. Hiking in moderate temperatures of mid-50F with light precip and high humidity is my challenge. There's nowhere for the sweat go to!
It would be interesting to see the results compared with a poncho and the same data tracking. DriDucks would have made an interesting product to include too.
Thanks for all the hard work and myth-busting!Oct 26, 2011 at 3:04 pm #1795320
@rcaffinLocale: Wollemi & Kosciusko NPs, Europe
> 2- The marketing pitch for WP/B fabrics hinges on a consumer's belief that they can
> actually stay dry when it's wet outside. My experience is that this is flawed
Right on Andrew!
This is pure marketing spin of the worst sort, and Gore are particularly at fault here for deliberately trying to deceive the public with their 'guaranteed to keep you dry' claim.
My solution in rain is a silnylon poncho and expect to get wet from condensation underneath. But it's warm-wet, not icy-cold-wet. And my pack is waterproof!
CheersOct 26, 2011 at 5:02 pm #1795353
@olivernissenLocale: Yorkshire Dales
Thanks for the hard work you've put into this, but I have to second Roman Vazhnov on picking up a number of minor issues that need consideration and add a few other points/corrections. I'll try to make this as brief as possible….
Roman rightly points out the importance of where the humidity sensor is placed in relation to zip openings. I used to own an Arc’teryx Alpha SV jacket, which proved to be useless protection from the cold in anything stronger than a breeze as its storm-flap-less pit-zips offered no resistance to wind penetration (but hey, great ‘breathability!’) On the opposite side of the coin, a big problem with zips is the amount of extra seam-tape they require which locally prevent moisture transfer out of the garment – if the jacket is closer fitting, this effect will be worsened as there isn’t as much air movement inside the jacket.
Roman points to other sets of factors to take into account – aspects of the fabric performance (aside from the membrane) and garment fit make a big difference to breathability and insulation. (Why, you may ask should we separate fabric performance from membrane performance? Well all the branded membranes are offered to brands with a range of different face fabrics, and sometimes different linings too. More on this a little later…) Anyway, here are my points about fabrics:
Firstly, garment fit coupled with fabric stiffness and weight has a noticeable effect. Stiff baggy shells (e.g. shells with laminated fleece linings) hold much of their surface away from the wearer, and with static folds of excess fabric, trap spaces of still air inside the garment – effective insulation. (This is partly why stiff heavy shells are popular in the sailing fraternity.) Of course more insulation = more heat stress = more sweating = humidity. It’d be very difficult to measure this effect, but it’d be interesting to hear if Will thinks this might have been a factor with any of the test pieces.
Still relating to fit, the second factor is garment coverage – how low is the hem and high is the collar? More coverage = more insulation and more area where sweating’s evapourative-heat-loss is hindered = more heat stress = etc. (you know the equation!)
Thirdly, the insulating effects of a shell may go further. If a shell is closer to equalising its temperature with outside cold it will promote more condensation on its lining which will reduce our humidity measurements (though not necessarily improve comfort over the long-run – which depends on what then happens to the condensation – my next point.) It’d be interesting to see the R-values (insulation) of the different text piece fabrics. (I really don’t know how much variation there would be and nor do I know how far this might affect condensation – can anyone enlighten me?)
Fourthly, if higher air-permeability allows wind to rapidly cool the jacket’s internal microclimate, then condensation and attendant higher conductivity and evaporation chill will occur deeper inside a layering system (if midlayers are worn – not in this test) as the dew point moves inwards. (Note that venting after building up a sweat will also have the same effect – so it’s best venting before you get all hot and sweaty in the first place!) This is only mitigated by the fact that as the jacket is so breathable, less humidity will have built up inside it in the first place. Of course this point is part of the common objection to air-permeable waterproofing – it’s not entirely windproof.
My fifth point is how shell linings aid comfort in a way not measured by this test – a good lining will absorb condensation or otherwise make it more acceptable (why 2.5L isn’t as comfortable as 3L). Maybe Chris Townsend’s experience with Neo and Active shells having less condensation than eVent is that they are faster at absorbing and spreading out condensation than the rather run-of-the-mill light grey tricot that lines eVent fabrics?
This brings me on to the sixth and final point. Point #4 in the article doesn't emphasise that any particular membrane will be laminated and sold with a wide range of different face fabrics all with their own varying levels of performance – it's not that one fabric is always mated to another membrane. I’ve seen suppliers’ own lab-test results and the same membrane will have vastly different MVT scores when laminated to different faces (sadly I’m not at liberty to quote figures). To sum it up, there is little consistency for the consumer to rely on and no marketing that one can take at face value – what's new?!
An aside… midlayers and insulated shell technologies can hinder moisture transfer in your layering system far more than the shells that might be worn on top of them. My Mtn Hardwear ‘monkeyman’ jacket is a bad offender. With ‘high-loft’ surfaces on inside and out, it is densest in the middle so capillary action doesn’t work in its favour. It seems to be particularly good at just holding moisture and getting claggy (unless I wear it exposed directly to the wind, in which event I may as well not wear it at all). Other bad offenders are synthetic fibre insulated garments (Primaloft etc) – two windproof layers with a thick still layer entrapped in a hydrophobic mat – all is not good on the moisture transfer front. Warm though! (I’d be curious to see how quilting shell and/or lining to Primaloft might vary breathability – a wind-flapped shell layer could help convect moist air through the otherwise inert fibre mat.)
Finally those (slighly anal) corrections I promised:
As Roman pointed out, GoreTex membranes generally aren’t air permeable (Their tent membranes are and perhaps Active Shell is too?!)
“A plain woven fabric without any membrane or coatings can be very breathable… but not water-resistant” – I dispute that. A dense weave/non-woven fibre mat + DWR, or Ventile can be highly water resistant.
“A polyurethane membrane requires two phase changes (vapor to liquid to vapor) to vent moisture” – true for hydrophilic PU membranes (and also that famous polyester-polyether block copolymer membrane- Sympatex), but there are also hydrophobic microporous PU membranes too. These act much like ePTFE. I suspect Neoshell is one of these and as I’ve hinted above, Gore’s Active shell maybe a combination of ePTFE + microporous PU, as opposed to their usual ePTFE + hydrophobic PU lamination, but I might be wrong?
There… I'm done! :)
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