Octa vs Alpha Direct: A Head to Head Comparison

[JCH]

There has been a lot written in these forums about these two fabrics, and rather extensive scientific tests have been published here. Both fabrics have their proponents and converts. Hoping to simultaneously increase my warmth and decrease my pack weight, I purchased a Mountain Hardware Airmesh Crew (size L) and a Timmermade 4004 (90gsm) Hoody (size M) to try them out for myself.  The MH Crew was on sale for $53 (normally $80). The Timmermade was $89 + $15 shipping.

A little about myself: I am 6’1″ tall, 220 lbs, 43″ chest and 66 years old. A lifetime Florida resident who only camps in the late Fall to early Spring due to the insane heat and bugs of the “warm” months in the SE US. I have always considered myself neither a cold nor hot person, but do seem to be sleeping a little colder as my metabolism slows down. I truly enjoy being out in the woods when the temps range from 10F to 50F. My interest in these fabrics is solely warmth for weight. I’m not really interested in wicking properties or how each handles sweat as I am careful to avoid sweating in the winter, thus I chose not to test these properties.

Evaluation conditions: We recently had consecutive days with morning lows of 42F and 41F. On these two days I wore each garment against the skin under a Montbell Tachyon Hooded wind shirt during my morning e-bike commute to work…the Octa at 42F, the AD at 41F. Other than gloves and a bike helmet, these two items were the only clothing on my upper body. I dressed identically for each ride with the exception of the two garments being evaluated. The commute lasted about 20 min at speeds ranging from 13 to 20 mph, with an average of 15mph.

My experience:

• Both Octa and AD are very soft and comfortable against the skin. I would not rate either one above the other in this regard.
• I found no appreciable difference in warmth between the two. I was cool, but in a good way with no sweat or condensation in the wind shirt…pretty much perfect for the ride.
• Visual inspection would lead one to think the AD would be slightly more bulky, but in practice they seemed to layer nearly identically.
• While the garments differ in labeled size, I found each to fit nearly identically. The Timmermade sleeves were slightly longer, but the MH had thumb holes to anchor its slightly shorter sleeves. I did not have any fit issues or complaints with either of them.

Conclusions:

• I like them both equally for the purpose stated above, and would be perfectly happy with either.
• For active hiking in cold and/or windy conditions, I would mostly likely choose the Octa (together with the Tachyon) only because it seems a little more “sturdy”.  I really can’t see the Octa wearing out with a modicum of care.  The AD just seems a bit more fragile, but time may prove this wrong.
• I intend to use them together for in-camp layering, most likely with Octa under AD. They will also be a primary component of my sleep system.
• You cannot find an AD garment on sale anywhere, and in fact many (most?) of the vendors I found were sold out.  Knowing what I know now, were I to do this over I would probably take advantage of a MH sale and purchase 2 Airmesh Crews, one size L and one XL and layer them. Given the easy stretch of Octa, it may be that two identically sized crews would also layer well.  This choice would be solely a function of cost.  BTW, Amazon has a few Airmesh currently on sale for as low as $36!!!

I have a 4 day trip planned in two weeks and will be evaluating these new layering components in different variations then.

[YoPrawn]

Also try testing the air mesh inside out. Changes the feel and character of how air and moisture are handled.

Teijen Octa was originally designed with the smooth side in and not out. The air mesh shirt is the first I think to use it with fuzzy side on skin.

So, it was clearly designed to go both ways.

Airmesh also work vastly better as a camp towel.

layering both is also an excellent combo, as you found out.

[JCH]

YoPrawn – your claims that Octa performs differently depending on which side is out make sense.  But I wonder if there is any difference when it is strictly an insulative layer? Something to test.

[John S.]

The octa reminds me of a thin 3D mesh with one smooth side and the other being open mesh. I would never use it as an outer piece unless maybe in camp. It seems fragile and easily torn with bare hands.

[JCH]

It seems fragile and easily torn with bare hands

I can’t agree with that.  Yes, it is very light but, at least with the MH crew I have, you would have to purposefully work to rip the fabric.  Almost certainly the seams would fail before the fabric itself.

I do agree that it has no business being an outer layer unless you are in camp or completely out in the open with no vegetation nearby.

[John S.]

I hear ya JCH. I shoulda just left that sentence off since most anyone can damage gear by yanking on zippers, etc.

[Justin W]

Almost bought the cheapest version on that amazon link, but I really don’t like that yellow shade, so didn’t.

As an aside, the warmest per weight, woven, single layer top I’ve ever experienced so far, is a no name brand from Taiwan I believe that made a top/baselayer style ls shirt made with hollow polypropylene fibers.  Polypropylene is 34% less dense than polyester, and a bit less thermally conductive than it as well. The top is surprisingly warm while weight wise, feeling almost as light as a thin silk fabric. It was also very reasonably priced (it came directly from overseas). The other nice thing about woven PP fabrics is that they dry faster than even polyester.

The downside of polypropylene is the odor issue.  However, I don’t ever wear it as a baselayer, and odor wise, it works much better as a mid layer.  Besides, my favorite baselayer is a fishnet type fabric anyways (current favorite among that group is a 80% nylon 20% spandex blend fishnet ls hooded top. It’s very comfortable and doesn’t get near as stinky as polyester and when it does, it is easier to fully get rid of it. My “ultimate” though, would be an alpaca-synthetic blend, but I will have to get that specially knitted).

The 2nd warmest per weight top I have ever tried, is the old, fleeced on the inside, military polypropylene heavyweight baselayers (again, not ever worn as a baselayer in my case, but as a mid layer over fishnet or something else).  I suspect that the Octa fabric may be slightly warmer per weight than this though, simply because of the hollow fibers which should increase insulation by about 20% per same volume/loft and every other factor being the same (while also lowering the weight a bit).  At least, this is what Polartec used to advertise about their “Aircore fleece” made with hollow polyester fibers, and which seems like a reasonable number.

(The downside of hollow fibers is that they are more fragile than their solid, same sized counterparts).

[JCH]

(The downside of hollow fibers is that they are more fragile than their solid, same sized counterparts)

Wondering if the ribs of the Octa fiber might add significant strength that would be lacking in a round hollow fiber?  I know (the manufacturer claims) that the ribs add significant warmth.

[Justin W]

Possibly, but without tensile and abrasion testing hard to say for certain.  But yes, the ribs would add some extra insulation since it would be better at stilling air than a completely round and smooth fiber (just think of aerodynamics in relation to larger objects, a round, smooth surface allows air to move over it more efficiently and with less drag/friction). Generally when talking about insulation in relation to single layer, non lofted fabrics, the hierarchy of insulation goes something like this (in order from most important to least important of factors):  Size of the fiber (smaller/finer fibers can still air better than larger provided there are more for a given area), hollowness or lack, shape of fiber (round and smooth vs trilobal, round but with ridges [like some animal fibers], etc), and the thermal conductivity of the material itself*.  (One could also factor in IR factors, but that is less relevant to most regular clothing materials).

* This can play a bigger factor when there is a more extreme contrast. But all in all, there is not a large enough difference between the thermal conductivity of polyester, nylon, polypropylene, cotton, linen, hemp, etc to factor that in at a more immediate and higher level.  Where it can and will come into play is with more exotic materials like oriented/highly crystalline UHMWPE fibers (such as found in Dyneema and Spectra fabrics, cord, etc).  This material has such a high thermal conductivity–on par with some metals, that your body/skin very much notices the difference even though the fibers are trapping some air and thus providing some insulation via stilled air.  But materials like this are the exception and not the rule when it comes to clothing.

However, now that specialized aerogel particles are starting to get infused into polyester and the like (see latest iterations of high end Primaloft insulation for an example), this may become a bigger factor in the future.  (Graphene is also starting to be infused into polymer type fibers, such as in Kyorene, and graphene is ultra thermally conductive–one of the most thermally [and electrically] conductive materials so far known. The company that makes Kyorene so far has infused/embedded it into nylon and UHMWPE fibers/materials).

[Weekend Gear Guide]

The air mesh shirt is the first I think to use it with fuzzy side on skin.

I believe the Rab Vapour-Rise Summit Jacket was the first to use the fuzzy side on the skin, since it came out in 2020, while the MH AirMesh collection came out in 2021.

Here’s a clip @ 2:54 showing the fuzzy side of the Rab VR Summit Jacket as well as comparisons of air permeability (as determined by the the Pertex Air shell of the jacket which is the bottleneck).

Active Insulation Jacket Series – Part 1 – Technical Introduction

There’s some other comparisons of Polartec Alpha Direct and Teijin Octa in this video that some folks here may be interested to learn and know more about.

[Diane “Piper” Soini]

I have both the Airmesh and a Senchi. I think both are really good. It strikes me that wearing the Senchi is a lot like what it might feel like if humans were furry.

[Bill Budney]

I like the Airmesh a lot. XL weighs 5oz. I wear it under a wind shell in freezing weather; it gets warm above that. But it never gets really uncomfortable; it is excellent at moving moisture off the skin.

It’s funny that it doesn’t pack really tiny. It takes almost as much room in my pack as a puffy vest (which is warmer). But the Airmesh is an excellent base layer.

[Bill in Roswell]

This is a public service announcement for MH Airmesh Hoody in a dark color is on sale for $64 at the Mountain Hardware store. Via Amazon for me is how I found it.

[JCH]

New Octa data point:  Same ride, same clothing, but 52F.  Definitely too warm!

[Brett Peugh]

I don’t know how you folks ever find these Airmesh on sale because I have never found an XXL for less than $70.

[JCH]

They are pretty stretchy, you might find an XL fits fine?  Free returns from Amazon.

Amazon XXL Crew: $64.97, $67.20, $49.60.  That last one is real bright…but it’s a baselayer :)

Amazon XL Crew: $43.20, $40.17, $55.93

Amazon XL Hoody: $50.36

Backcountry XL Zip: $53.99

Mountain Steals XL Crew: $43.99

[Brett Peugh]

Thanks, I actually like the Starfruit color.

 

I actually went back to get another Starfruit in each size and they switched back up to $80 each,

[JCH]

Amazon does that. There is a reason they are hugely successful…kinda ruthless really

They also have multiple vendors for the same item…pay attention to the “ships from” and “sold by” under the “add to cart” button…it changes constantly, often when an item is sold so it can change while you are shopping the item!

[Brett Peugh]

Thanks, I picked up a variety of things and will know in the next few days if they fit.

 

[Brett Peugh]

Thanks JCH

I have been layering an Airmesh crew with a hoody and they seem to work without crushing each other.  If layering with AD I would be more apt to layer the Octa over the AD because it can take a bit more abuse and the AD is much more porous, maybe act more like those fishnet baselayers people are using.  but i have been swapping around a 90g and 2x60g AD with a the crew and hoody Airmesh and they can compliment each other when layer.  It will be good to hear your experiences.

[Ethan A.]

@JCH, thank you for the helpful comparison as I was just looking for info to compare Octa and Alpha Direct. Did you feel there was any difference in wicking between the them, and did you feel Octa lost warmth when you were sweating, as Stephen Seeber found in this BPL review he wrote?

[JCH]

@Ethan A. – My testing was conducted in conditions in which I did not sweat…cannot comment on performance if you are sweating.

[Bill Budney]

I have an Airmesh half-zip and I like it a lot. I wear it as a base in sub-freezing weather. It works well that way; no issues with moving sweat. It is highly permeable. It weighs 5oz and is very warm for the weight.

The Airmesh does everything I want, and I prefer a zip when it becomes too warm. However, I haven’t tried AD, so cannot compare the two.

[JCH]

FYI for anyone looking to purchase…quite a few deals in multiple sizes on the crew and zip

[baja bob]

Check Steepandcheap.com. I think they have 1/4 zip and hoodies for less.

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