Polartec Alpha?

[Hans Dampf]

Richard Nisley, thanks a lot for the detailed and easy to follow explanation. The term “active insulation” is a bit confusing in my opinion. If I understand this right then active insulation is basically a fixed windshirt (shell) + fleece (insulation) combination that works for a particular activity – which limits it;s use of course. The difference is that it doesn’t have the additional benefit an air gap provides.

My next question would be, as Jared mentioned: From a personal perspective, the windshirt + fleece makes sense for activities like hiking where body temperature doesn’t change too quickly.

However, in winter I do a lot of ski touring in the alps, at night. And usually I sweat a lot as we try to race against each other. The typical temperature is from 0 to -15C. Depending on this temperature I take my Rab Photon + an older softshell if it’s cold, or just a powerdry long sleeve shirt. After getting warm, I usually take off the Photon unless it is really cold or very windy. As soon as I’ve arrived on top I have to dress warm again very quickly as it gets cold very fast at a higher altitude.

I’m still wondering if I could do better, regarding the clothing so I would very interested in your opinion (knowing it’s not the typical hiking scenario discussed here). What would you suggest to try in this case?

Thank you very much for all the insight!

[jared h]

Also curious to see what other people are using, but here is my current setup for below freezing snowshoeing/ski touring in the Cascades and inland NW: 120-150 wt merino base and mountain equipment eclipse hoody always on, rab photon for stops/decents, and insulation is usually patagonia nano air light hoody.  if it’s <10F (higher altitudes, night) I might go with a warmer insulation piece–just got an acrcteryx proton ar that is doing well so far. Also always carry a shell in the pack. I sweat a lot and this system is keeping me pretty comfortable.

[Bradley Danyluk]

I have a weird sweater from MEC that is made of just pure 120g Polartec Alpha material (with NO shell on either side) – they don’t make it any more and any reference to it is even gone from their website. But the fact that it was made without a shell was interesting to me and provides lots of opportunities to test how the insulation itself behaves in different circumstances.

This is my take on it. Yes it’s more breathable than other insulating pieces, and yes it’s warmer for the weight than regular fleece. But it has a big problem: when it gets wet, it’s absolutely horrible. The loft is completely killed and It turns into a flat, sopping wet mop. It takes on huge water weight, feels awful and freezing against the skin and seems to lose all insulating power. Therefore it’s useless to me (I bought it basically as a classic fleece replacement – for insulation in conditions where you just can’t stay dry). Unfortunately, classic fleece is still king, by far, in situations where there’s any chance of it getting damp or wet.

I can see it might have its use cases for dry, high-activity situations, but my take on that is that if it’s cold enough that you need insulation but your regular insulation makes you sweat too much… you’re just wearing too much insulation.

[Eric Blumensaadt]

Can we stop here? I think my brain is full.

[Richard Nisley]

As the old saying goes, “the chain always breaks at the weakest link” whether lifting or learning (smile).

[Jeff McWilliams]

Bradley,

I don’t own a piece of Polartec Alpha clothing, but I find your experience with it getting wet odd and feeling like a wet mop odd.  From what I have read, Polartec Alpha was developed in conjunction with the US Military as a better performing fleece layer.

Also, I don’t think it was designed to be worn against the skin, but as a midlayer, and by most designs I’ve seen, encapsulated by inner and outer breathable fabrics.

From a separate article here, it’s written that,

The story goes, soldiers were ordered into a river for five minutes to soak. The Polartec product wasn’t the only fabric being tested; there were several different fabrics in the water. Once soldiers were soaked, they were ordered to “walk their garments dry,” which meant hiking in the cold while dripping wet.

The idea behind this test was that body temp will dry the fabric out eventually. Polartec Alpha not only passed the test and beat the competition, it was reported to be one of the best Special Forces products ever tested, Cohne said.

The SOF PCU Level 3a jacket is a military clothing item that uses Alpha.  You can find a Patagonia version, currently quite affordable, here on the Patagonia website.

 

[Kris]

Jeff, that Patagonia jacket (PCU 3A) is the most versatile jacket I’ve used.

I haven’t used any other Polartec Alpha clothing so it’s difficult for me to say how much of PCU 3A’s performance comes from the insulation rather than other features like the cut or the fabric.  But evaluated as a whole, 3A is outstanding and easily my favorite jacket for hiking.  3A can be worn across a wide temperature range, is surprisingly durable, is light & packs small, and dries quickly.  It has the best cut of any jacket I’ve worn.  The bottom hugs your hips and does a great job of trapping a layer of air as insulation.  The only weakness is the zipper (zippers seem to be the worst feature of every jacket I own).  The base of the zipper is small and this requires some attention to make sure you are actually seating the zipper properly.  On more than one occasion, I’ve had the zipper come apart (once because a dog jumped up on me) and it’s a pain to fix.

For most situations, I use PCU 3A rather than the fleece jacket, PCU 3 (which is a very different jacket than the ECWCS 3 jacket that is occasionally mentioned at this forum).  If I’m going to be working hard (like a quick mountain ascent), then I prefer traditional fleece and the way a winter wind cuts through it – keeps me cool.  But other than that, I grab 3A instead of 3 for hiking.

Kris

[Jeff McWilliams]

@Kris,

Aww man.  Just when I had myself convinced that there was nothing special about owning an Alpha jacket, you have me second guessing.  :-)   At $106.00, it’s a lot closer to my marginal propensity to consume than high end Alpha jackets from Patagonia, Rab, etc.

 

[Richard Nisley]

Kris,

I have tested a PCU Level 3 (Malamut) and the ECWCS Level 3. To me, they appear to be equivalent jackets in that they are both built with Polartec Thermal Pro (#4060) in 6.4 oz/yd2 material. This gives them the same insulation value and air permeability. They do differ in the feature set; the PCU L3 has both a neck and waist bungee plus thumb loops and no nylon wear patches. Is this what you mean by very different?

My tests have shown similarly high HH from the PCU L4 products available from different military contractors but, dramatic differences in their CFM. For example, the multicam version of the WildThings 1.0 tests near the optimal range (35 CFM) at 29.8 CFM and their Coyote color version tests 1.8 CFM. The Beyond Clothing (Bora) version tests .58 CFM. Users will have widely varying assessments of the PCU Level 3 breathability based on which version they used.

I understand the benefit of the PCU Level 4A for use under body armor; layering changes are prohibitively difficult. For hiking, in a wide range of temperatures, a PCU Level 4 windshirt only (29.8 CFM), PCU Level 3 fleece only, or PCU Level 3 fleece + PCU Level 4 windshirt provides a dramatically broader insulation and breathability spectrum for me.

[Bradley Danyluk]

My mistake – I finally found a reference to my garment online (MEC Amenity) and it turns out it is High Loft Thermal Pro, not Alpha as I thought.

[Kris]

Richard,

“Is this what you mean by very different?”

Yes, it was the wear patches on the shoulders, forearms, and torso sides that I was thinking of.  They are unnecessary and take longer to dry out.  But I don’t think PCU 3 and ECWCS 3 are exactly equivalent.  Stick your fingers inside the sleeve of them both.  The sleeves of the Malamute are thicker.

“Users will have widely varying assessments of the PCU Level 3 breathability based on which version they used.”

We didn’t use PCU 4 so the characteristics of the windshirt wouldn’t have any bearing on our assessment.  I’ve noted that you advocate a windshirt and a fleece as being ideal.  We reached a different conclusion.  The internet being what it is, I better first explain that the following is not meant to be argumentative and I write it only because you have an interest in the SOF-PCU.  Windshirts are one of the least useful pieces of gear we’ve been issued whereas the 3A is almost certainly the most well-liked piece of gear ever issued.  But, as an aside, I do find it very interesting that you found multicam to have such different characteristics than coyote.

“I understand the benefit of the PCU Level 4A for use under body armor; layering changes are prohibitively difficult.”

For reasons that aren’t really relevant to this conversation, body armor isn’t much of a factor.  However, you’re right  that layering changes are a factor.  With PCU 3, I need an additional shell to make Level 3 work in high-wind.  With PCU 3A, I do not.  I can work up a significant sweat during an ascent and not be concerned about that sweat cooling me down too much when exertion ends at the ridgeline.  3A handles high-wind very well.  It might be worth pointing out that the conventional military operates differently.   A guy on my team (if you watch the movie Blackhawk Down, he’s the one who gets the digit shot off in the street) had been in a conventional unit in Alaska before going SF.  He told us that he had been taught to never move fast enough to work up a sweat in winter.  But SF doesn’t operate like that so 3A works really well for us.  Even so, as I mentioned, there are times when I prefer 3 to 3A.  But those tend to be for specific activities.  As an all-around garment, 3A is the most versatile I’ve used.

Kris

 

 

[kevperro .]

I was in the 1st/75th just before Somalia.   In the Ranger Battalion they didn’t let individual soldiers determine when to wear layers.  I was just a cherry at the time and wasn’t the one making the choices but they really error on the side of keeping you cold rather than exerting and sweating.   There were times it made no sense but hey.. that is the military for you.    You learn to suffer accordingly.   I remember one event in RIP where one guy put on his polypro without permission (all night land navigation testing).    The Ranger Instructors had us doing pushups to exhaustion (35 deg. rain) in Georgia clay, rolled us over and had us doing let lifts to exhaustion, rolled us over and push-ups…etc…etc..    The guy wearing his polypros was given a donut and made to point and laugh at the rest of us while we got smoked for at least an hour.

I have to say it had some value.   I’ve never been really uncomfortable hiking and living outdoors ever since.   Once you can choose your clothing and when to put it on that makes a world of difference.   ;-)

[Kris]

“The guy wearing his polypros was given a donut and made to point and laugh at the rest of us while we got smoked for at least an hour.”

Haha!  Awesome.  Gotta love the Army!

When I was in the 18D Course, one of my classmates summed it up.  The morning accountability formation was taking forever (we guessed that the freezing rain had delayed the instructors – but who knows?) and we were left standing outside in the dark in the freezing rain for about 45 minutes wearing only our BDUs.  I heard a classmate say to another: “Bert (Bert is now one of the instructors on The Selection on History Channel), you gotta love the Army!  What other job will you find grown men being forced to stand around in an ice storm without rain gear instead of letting them just walk 10 meters to come indoors?”  But, yeah, it does have value.

[Richard Nisley]

Kris,

Thank you for both the comprehensive response and your service!

You were correct that there is a small thickness difference between the Level 3 Malamute and the Level 3 ECWCS.

You said, “Windshirts are one of the least useful pieces of gear we’ve been issued whereas the 3A is almost certainly the most well-liked piece of gear ever issued.” A windshirt, a softshell, a PCU Level 4, a PCU Level 5 and to a lesser extent PCU Level 3A are largely synonyms. To state one is useful and others are not merits some additional discussion.

PCU Level 3 and ECWCS Insulation Amounts
I did the in-sleeve-finger-on-each-side test and yes, I could feel a small difference between the thickness of the two Level 3 garments. To confirm the tactile assessment, I then measured the thickness with a Mitutoyo 547-400. The ECWCS averaged .928mm and the Malamute averaged 1.063mm (12.7% difference). The Natick lab test of the ECWCS Level 3 measured 1.3 clo (minus .6 clo boundary = .7 Iclo). The Malamute should then be 1.127 * .7 + .6 = 1.39 clo. To put those insulation amounts into perspective, the lightest Montbell down jacket is the Plasma (4.8 oz. size M); it is 1.57 Iclo + .6 clo boundary layer = 2.17 clo versus the .09 clo difference between the two Level 3 fleece varieties.

PCU Level 3 and Level 3A Insulation Drying Time
Combining packrafting with backpacking, I frequently hit dry land already wet, take off my non-fabric-covered fleece, and swing it vigorously above my head to remove almost all of the water. As you stated, nylon wear patches on the ECWCS slows its drying time. Two windshirts permanently bonded to a fleece (Level 3A) will further slow its drying time relative to just a fleece. In contrast, a layered windshirt and fleece separated to initially swing dry and then air-dry with double the surface area to speed up the drying time.

Level 3, Level 3A, Level 4, and Level 5 Semantics
In your work application, you already have your Level 5 which is equivalent to a Level 4 relative to them both being Epic shells (permanent DWR) with comparable HH and CFM. The primary difference is the Level 5 is twice the weight to be more than twice as durable and more fully featured. Either one will suffice as a soft shell but, as an UL backpacker weight trumps features and durability. A soft shell with a little more insulation is the same as a PCU Level 3A.

Whether you call this garment functionality a windshirt or a softshell they are the same basic functionality; whether you call this garment a Level 4 or Level 5 they are the same basic functionality. A Level 3A is a Level 4 permanently bonded to a L3.

PCU Level 4 or Level 5
Both your Level 4 and Level 5 garments are Epic nylon with comparable HH and CFM ratings. The Level 5 is double the weight, is more durable, and has more features. Your Level 4 or Level 5 are largely equivalent functionality. An UL backpacker who needs either a small amount of additional insulation, protection from convection heat loss, or both, a Level 5 is prohibitively heavy relative to a Level 4. If the aforementioned case requires even more insulation, an appropriate warmth fleece can be added to the ensemble. Alternatively, a PCU Level 3A or equivalent commercial garment but with a slower drying time, less insulation granularity, and a lower insulation system clo/oz (my 12/7 post earlier in this thread).

[James holden]

The issue with windshirts and fleeces underneath them is faff ….

consider the following systems

windshirt + fleece in winter …. To put on the fleece under the shell u need to

1. take off the pack
2. take off the windshirt
3. pull the fleece out of the pack
4. put on fleece
5. put on wind shirt
6. put on pack

now consider a popular climbibg combo a windshirt/softshell and a micro synth poofay

1. take off pack
2. pull micro poofay out of pack
3. put on micro poofay
4. put on pack

now consider one of these “active insulations”

1. zip it up

no taking off packs at belays or dropping gear …. No faffing about with gear in high winds … No losing heat by taking off yr windshirt …

for “normal” hiking it probably doesnt matter as if you drop something u just pick it up and u arent hanging from a ledge

theres a reason why synth micropoofays have taken over from fleece in the climbing world …. And now it seems “active insulation” is making inroads as well

Similar sports where you cant “faff around” might have similar requirements

;)

 

[Bob Shuff]

I had to look up faff.  My faff (word) of the day I guess.

What would you consider a popular version of a micropoofay? I’m clearly behind the lingo times.

[James holden]

Bob

da pataguccu nano poofay, rab xenon or any other 60g/m synth poofay

basically something you can move slowly, technical terrain, or cold weather in if needed … But in warmer weather you can use as a fleece replacement, in fact its roughly as warm as a 200wt fleece + windshirt

when they first came out circa late 2000s they were all the rage, used by top climbers

now it seems like the top climbers are switching to “active insulation” jackets

for “normal” hiking a windshirt/light softshell + fleece is more flexible …. But there are those where “faff” is a time killer … And when you waste enough time at belays, or risk getting gear get blown away … Or are pushing the limits (not me) of human ability …. Then all the added faff may literally be a killer

;)

[Richard Nisley]

Eric,

You initially put on an active insulation layer garment (soft shell layer(s) and insulation layers integrated) and leave it on for the duration of active use in most situations. These garments handle a wide range of temps because when the average skin temp rises from 95F to 98.6F  the skin perspires and cools the occupant. The very low moisture resistance of both the insulation and the soft shell(s) allow this to happen. This is in contrast to a conventional insulation garment with Primaloft Gold or down. The shells have to be less than 10 CFM to prevent fiber migration. This low level of breathability prevents rapid temperature skin temperature adjustment without insulation degradation.

You initially put on a fleece and then a softshell (windshirt) and leave it on. The reason it works is identical to the above explanation.

Neither option precludes you layering it with another garment when you are not active.

I always thought you were one of the more pragmatic posters but, FAFF that (smile).

 

[James holden]

Richard …

thats what i call overheating in “moderate” (above freezing) conditions going uphill =P

theres no way im keeping on the windshirt + fleece as an action suit unless its below freezing with a good wind …. And maybe not even then

id be sweating buckets

one thing to note is that some of these “active insulation” pieces are of hybrid construction … With fleece or lighter panels on the sides and back …. Which makes em quite breathable …. Many are meant for trail running

i havent seen many folks trail run in a fleece + windshirt …. I dont even walk fast and id die of het exhaustion if i did

;)

 

[James holden]

Last week wearing a fleece + windshell on a lazy walk on the flat/downhill … Theres no way id wear it going uphill, the fleece cane off then

one other issue with fleeces in winter is that even under a shell they have a nasty tendency of collecting sticky snow, especially if u unzip the shell to vent or if you choose to tumble in the snow (glissade, dig through snow, etc ) .. More so than most other clothes

no surprise when one hair (less fuzzy than fleece) collects the snow and freezes solid

;)

[Richard Nisley]

Eric,

The layer under the soft shell should be chosen for the environment and your average MET rate.  At the low end, a Capilene 4 is a typical base/ insulation choice. In small increments there are fleece alternatives up to the Patagonia R3. Contrast that will an integrated active layer such as the Patagonia Nano Air. Like Henry Ford’s early cars,  you have what ever level of insulation you need as long as it is 60 g/m2 (smile). For every integrated insulation system level you have to buy two more integrated soft shells (aka wind shirts)… ka ching… $300 Yankee dollars for each increment… ol FAFF.

[Hans Dampf]

Which is what Richard already detailed in a long posts some days ago btw. A very interesting topic.

What makes the topic more complex for me is the thought: Consider an activity, you either take a Fleece+Windshirt or one of the mentioned active Jackets.

It’s obvious that the active insulation covers a smaller (body) temperature range due the reasons explained. However, the Fleece + Windshirt combination in contrast acts more like an On/Off switch which might result in a situation where you’re constantly taking on/off the windshirt in case you overheat, get too cold, overheat.. etc.

I think it is still more versatile of course but when I think about past activities I had this scenario especially during winter ski touring, sometimes – it probably is just a sign that I took the wrong windshirt :)  I still favor the 2-piece approach though.

[James holden]

Oh a fleece + windshirt is much more flexible …. As is a windshirt + micropoofay

but then to use that flexibility fully you need to deal with FAFF =P

not to mention youll need every different weight of fleece to tailor your specific attire to that day (which i also have) …. Which cost you quite a bit

and when there decent difference between uphill and downhill/flat metabolic rates, wind in one area vs the other, temps at noon in full sunlight vs temps after the sunsets (4PM), etc … Putting on a particular fleece and expecting it to work no matter what the conditions for that day/evening under a shell may not be the most feasible …. One may need to deal with FAFF …

the thing is these “active insulation” pieces arent mean for lazy “hikers” … They are mean for folks who move fast and keep moving (even for belayed climbing, they dont waste time pulling out a belay jacket)

If you look at who they are marketed to …. Cold weather runners, light and fast climbers, backcountry skiers, etc ….

Not to mention that theres different weights, patterns and designs of these “active insulation”

for example the MEC obsession jacket (now 119 canuckistani on clearance) has fleece side and back panels … You wouldnt be able to duplicate that with a windshirt + fleece

similarly the dead bird argus (189 canuckistani on sale at the dead bird factory store) has fleece type backpanel, which i think might be a smart idea if yr wearing a pack (years ago camp tried selling a windshirt with an open mesh back for that purpose)

if you look at the price of these active insulation pieces … The ones i see tend to be about the same as a windshirt and fleece of the same brand and quality (well maybe not patagucci though their Level 3A is 109 yankee dollahz in clearance in XL now)

personally i like my fleece … But many good climbers (not me) havent been wearing fuzzy fleece (not R1s) for a decade or so

;)

 

 

 

 

 

[Woubeir (from Europe)]

OK, but first this. what is the primary purpose of wearing a fleece ?

[kevperro .]

I have a guilty confession….. I don’t own a fleece garment.   I had one back in the day but it got left at home for hiking because it wasn’t as warm as my puffy for camp and was WAY too hot to hike in.

Having said that I’d like the benefits of fleece for winter hiking, which is mixed rain here in the PNW.   You spend a lot of time wet in cold weather.  At least for my arms it would be nice to have a really thin layer of fleece under my shell.   My core stays plenty warm while moving so I’d overheat in all but the worst conditions with fleece over my core.

Does someone sell just “armlings” I can wear?

[Author]

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