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how breathable a wind shell is
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eric chan
(bearbreeder) - F
dead birds on 11/26/2012 23:30:19 MST Print View

i have a celeris and i find it quite breathable ...

windshirts are a mixed bunch ... some are no more "breathable" than a good WPB ... others are much more so ...

the only way to find out is to test it in the store and outside ... unless you have a book full of real testing ;)

it also depends on YOU and what you do ... for example scrambling up a steep hill vs. prancing around some flat trails ...

one question to ask is "do you really need a windshirt" ... if its not that windy, you can usually get by even when cold with a light breathable fleece ... if its really windy, youll get some cooling effect off that and one could just wear the WPB with zippers half open ...

know your gear, test it, use it ... dont think that you NEED any windshirt or any particular item because it is "popular" on BPL ...

Roman Vazhnov
(joarr) - MLife

Locale: Russia
CFM on 11/27/2012 02:25:37 MST Print View

Numbers of CFM, provided by Richard Nisley do not correspond with "traditional" numbers, provided by manufacturers, etc. For example for Squamish it was 7 CFM, for traditional fleece - around 200 CFM and so on. In my simple unscientific test by blowing through the fabric Squamish was significantly less air permeable than fleece. And i thought Boreas (and similar MHW Chocklite) is more air permeable than Squamish. But i don't have Squamish right now to repeat test again. I am confused.

nian zhang
(thotwielder) - F
Re: Re: how breathable a wind shell is on 11/27/2012 04:42:05 MST Print View

Great inputs from everyone. I can imagine a breathable wind shell can be useful a lot of time if not all the time and since it is so light. I will probably get a Houdini when I can get it on sale. Or a Rab celeris, or a Marmot ether driclime. I kind like the mesh vent on Marmot ether and it can be a midlayer under my shell since I will bring my shell anyway.

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: CFM on 11/27/2012 06:32:38 MST Print View


Windshirt fabrics for the same model can change from year to year. Unlike the Houdini, I only checked one model year for the Sqamish. Polartec fleece types are a good reference because they are consistent. The classic fleece tests at 254 CFM and newer double face versions test at 325 CFM.

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: Squamish on 11/27/2012 06:47:12 MST Print View


I have not tested any of the recent Squamish model years. Unlike the Hudouni, I don't know how the value changed for each model year. The one I tested has the Acteryx model listed as: Squamish Windshell - Men's – ARCTERYX; Item #: 202600; Price: Reg. $139.00. In their marketing description they called the fabric Gossamera nylon.

Don Wilson | 2008-04-08 14:49:00-06 reviewed the same windshirt in BPL. He described the breathability as, "I was pleased with the breathability of the fabric, which seemed on par with similar windshells. What I like best about the fabric is the soft drape and comfortable feel against my skin. The fabric is less smooth than the fabric in many lighter windshells, and doesn't make me feel like I am wearing a plastic bag."

I found that same air permeability in the Squamish Windshell as the MH Canyon shirt and the RR Adventure shirt. Both of these shirts are designed for summer use.

Edited by richard295 on 11/27/2012 08:32:34 MST.

nian zhang
(thotwielder) - F
Re: Re: Squamish on 11/27/2012 07:24:53 MST Print View

Hi Richard,

It's interesting to know the Squamish has similar breathability as a normal shirt. Does it mean they have similar wind resistence? If it's the case, does it mean I can just use base layers to achieve the same effect? E.g. begin with a T shirt, if windy put on a long sleeve shirt. Can you test the CFM of a two bases combo like this? I am asking because I also always bring two base (T + long sleeve).


Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: dead birds on 11/27/2012 08:00:14 MST Print View


I am confused by the technical terms you mountain climbers use to describe air permeability. How does "quite breathable" compare to "windproof",” “wind-resistant,” and “breathable”? (smile)... just kidding.

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: Re: Re: Squamish on 11/27/2012 08:21:07 MST Print View


I most recently answered your question on combining air permeability layers here:

The Squamish I tested would have similar wind resistance (aka air permeability) to the main nylon fabric used in either summer shirt I mentioned. The summer shirts have an open mesh panel on the sides to achieve more air permeability and the Squamish has a deep center zip.

Edited by richard295 on 11/27/2012 08:33:32 MST.

Brendan S
(brendans) - MLife

Locale: Fruita CO
CFM measurements on 11/27/2012 08:36:48 MST Print View

Thanks for all the info, Richard; it's appreciated.

I'm curious if there are different types of CFM the post you just linked (from 09) you list the Houdini as 5 CFM compared to the 40+ in this thread (including model yrs 08 and 09). Are those different types of measurements?

Roman Vazhnov
(joarr) - MLife

Locale: Russia
Re: Re: CFM on 11/27/2012 09:02:52 MST Print View

Richard, yes i understand that the same model may have different fabrics from year to year, even fabrics with the same name can have different characteristics within the family. I wanted to say (+1 to Brendan) - may be there are different methodics? Because this numbers (around 100 for windshirt) are rather great. People used Squamish for winter backcountry travel and so on, and reviews said that air permeability was on pair with similar windshirts.

For example this are the numbers from your post in 2009:
"Polartec Windbloc 0 CFM… PU layer
Gore Windstopper <2 CFM Porous Teflon membrane without the Gore PU layer
eVENT <2 CFM Porous Teflon Membrane (hard shell product for ref only)
Driclime windshirt 3 – 5 CFM
Patagonia Houdini windshirt 5 CFM
Polartec Powershield 8 – 16 CFM Perforated Membrane
Polartec Windpro 60 CFM
200 wt Fleece 200 CFM"

Which numbers are correct? Maybe the numbers from the table above are from manufacturers, not from independent test?

Another assumption - was it (Squamish) new? Maybe PU coating inside was worn out?

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: CFM measurements on 11/27/2012 09:09:11 MST Print View


There is only one standard for air permeability. In contrast, there are a large number of different MVTR breathability standards. When comparing windshirt fabrics to eVent fabrics only air permeability is relevant.

In '09 I didn't own an air permeability tester. I purchased it in 2011 and tested the Houdinis from prior as well as subsequent years. In that old post I used the Patagonia Houdini air permeability specification that was in a Patagonia Power Point presentation that Mark Verber posted. Hopefully Mark can tell us the year of origin for that presentation.

Edited by richard295 on 11/27/2012 09:11:32 MST.

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: Re: Re: CFM on 11/27/2012 09:20:35 MST Print View


I 2009 I didn't own my own air permeability testing equipment and had to rely on vendor specs. In early 2011 I purchased an air permeability tester and since then I have used the old "trust but verify" approach to vendor's air permeability ratings (smile).

Roman Vazhnov
(joarr) - MLife

Locale: Russia
Re: Re: Re: Re: CFM on 11/27/2012 09:46:36 MST Print View

Thank you, Richard. Can you consider the opportunity to post the table with cfm for all garments you have tested?

eric chan
(bearbreeder) - F
Re: Re: dead birds on 11/27/2012 11:52:13 MST Print View

well richard ...

if im soaking in sweat more than a balding middle age man in a vegas porn convention ... it aint breathable ;)

absolute "windproofness" isnt usually an issue as youre putting on a belay jacket when not moving anyways ... and you may also have a light synth puffy when moving over technical terrain

Eric Blumensaadt
(Danepacker) - MLife

Locale: Mojave Desert
A little respect for balding, middle aged men please! on 11/27/2012 14:11:52 MST Print View

I'm not balding and I'm well past "middle age" but I DO live in 'Vegas. You mean they have porn conventions in 'Vegas? Geeze, now THAT would make me sweat so maybe I shouldn't wear my windshirt when I go.

"Seriousnessly", when hiking in mountains I always wear a long sleeved poly or nylon shirt for UV protection. That shirt is the only one I carry other than two poly T-shirts. Thus no DEDICATED windshirt. Of the four shirts I have the "511" brand nylon shirt is the most windproof and the polyester REI Sahara the least. The altitude and season dictate which one I take.

But still they provide enough protection that I can wear a medium weight (200 wt.) polyester fleece vest beneath them on cool, windy days and be just fine. Their vented backs are covered by my pack. Around camp the eVent parka goes on.

Mark Verber
(verber) - MLife

Locale: San Francisco Bay Area
Re: Re: CFM measurements on 11/27/2012 23:50:16 MST Print View

> that old post I used the Patagonia Houdini air permeability specification that was in a
> Patagonia Power Point presentation that Mark Verber posted

it was 2005. The Patagonia windshirt back then was called the dragonfly. My memory is that the first generation houdini which came out in 200? used the same fabric but a slightly different cut / zipper configuration.


Peter Fokkinga

Locale: the Netherlands
autumn 2012 Houdini on 11/29/2012 12:05:19 MST Print View


Do you intend to test the new autumn 2012 version of the Houdini (1.2-oz 10-denier fabric) as well?

I fear its "blocks more wind than the previous version" feature, in combination with the slimmer fit, could mean it is actually a step back from the previous version :(

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: autumn 2012 Houdini on 11/29/2012 12:42:12 MST Print View


I will test a Autumn 2012 when I get access to one. I don't have a scheduled date.

Michael Cheifetz
(mike_hefetz) - MLife

Locale: Israel
Pertex microlight - confusing answers??!?! on 11/30/2012 04:19:40 MST Print View

So I wrote pertex directly and Montane as well and received the below answers (that I am not sure about...)
Thanks for contacting Pertex®
Air permeability of Pertex® Microlight is less than 3cfm.

The figures we have from Pertex for Microlight are 1.0cc max (JIS L 1096/ ASTM D737).

anyone can figure this out? how does it sit within the scale @nisley measured the Houdini??

there is also this post by @nisley

Quoting 15.59 for the same pertex

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: Pertex microlight - confusing answers??!?! on 11/30/2012 13:00:56 MST Print View


The ASTM D737 standard on page 3 says, "11.1 Air Permeability, Individual Specimens—Calculate the air permeability of individual specimens using values read directly from the test instrument in SI units as cm3/s/cm2 and in inch-pound units as ft3/min/ft2, rounded to three significant digits.”

Pertex’s response of <3 CFM is the air permeability reading using the ASTM D737 imperial representation and the Montane’s response of 1.0cc max is the equivalent ASTM D737 scientific representation which is 1.97 CFM; they are effectively equivalent values.

15.59 CFM is what I measured for the Microlight fabric used in the Montane Lite-Speed version that Ryan Jordan, Roman Dial, etc. selected for use in the 2006 Artic 1000 trip. The hang tag on the fabric I tested said, “Pertex Microlight E.B.P. Fabric for Body”.

Also in 2006 Pertex sold the company to Japan based Misui. At the time of the sale there were at least 9 Quantum variants and 5 Microlight variants with different weights and air permeability ratings for each one. The Quantum variations offered a smaller air permeability range than the Microlight variations. Your 2012 Pertex Microlight product specification is different than the 2006 variant that I tested.

The ASTM D737 standard tests I conducted, for multiple years of Houdinis, use the same CFM test value representation as Montane and Pertex.

Edited by richard295 on 11/30/2012 13:19:43 MST.