Down as a midlayer?

Why are thinner down puffy jackets discussed as a separate class of layer than the currently popular active synthetic midlayers (e.g. arc Proton, Aton LT). Is the breathability really that different? If I have a midlayer sandwiched between an R1 and a shell, does it really make a big difference if it's a fancy active synthetic insulation or a baffled down jacket?

 A thin puffy seems well breathable to me, but I don't have experience wearing jackets like those mentioned above. 

I think they are breathable at least depending on the material used to sandwich the down.  I think the issue is the down “wilts” in the humid climate between skin/base layer and shell.  

I generally find down too warm for a mid layer but I run warm and haven’t tried very thin down pieces.  

My midlayers tend to be too moist for down to work.

Better is one of the new full-range synthetics that are designed to be very breathable, like Patagonia's nano-air.  

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In other news, it's a great idea. Let's all figure out the best way to sell our own gear and not support these big companies.

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I am wearing a Himali down midlayer that has a cigarette burn on the left wrist. Specifically, distal and the wound is _____ relative to ____. It's bleeding down but frankly, I literally do not care. The jacket cost three hundred bucks and it saved me from hypothermia that one time. Advantages of BASElayer usage is where I am now thread-drifting. Anyone done that? This one is super comfy on the skin.

I would like to offer one free puffy jacket (Loki Canyon, black, M) to the person who texts me at 0630 MST and reminds me to take my morning meds.

That is all.

 Will it make a difference? It really depends on how much you plan on sweating.

 “active insulation” pieces are indeed significantly more breathable than an equivalent down piece, and they don’t lose loft when exposed to moisture the way down would.

Consider also that down is much more compressible than active insulation synthetics. Your harness and/or backpack will create areas where the down is completely flat, possible creating cold spots. 

This, together with the moisture that will inevitably build up in your mid layer, makes down a poor choice in anything but very brutally cold weather. 

Victor Machtel wrote:

Consider also that down is much more compressible than active insulation synthetics. Your harness and/or backpack will create areas where the down is completely flat, possible creating cold spots. 

This, together with the moisture that will inevitably build up in your mid layer, makes down a poor choice in anything but very brutally cold weather. 

Some down jackets have synthetic insulation in the shoulders for just this reason, as well as synthetic insulation in the high moisture areas (armpits, wrists, collar around the mouth). A jacket made this way would be lighter and more compressible than a completely synthetic jacket, and would work well with a breathable shell. This would make down a good choice in cold, dry weather, even if it's not quite "very brutally cold".

True. Still, It'd have to be pretty cold for me to consider taking a down jacket as a mid layer instead of a reinforcement layer. But then I run hot and something like an R1 Air, good base layer and good shell keeps me warm enough during intense activity even in freezing temps. 

Most of my climbing is done in a Merino baselayer, R1 hoody and softshell. When it gets cold I use a super lightweight down sweater as another midlayer. I find it way more comfortable and a bit lighter than the synthetic I was using before. It seems to breath better as well. It has stretch panels in the pits and the side of the torso. Moves very nicely with my body. It's stupidly expensive but was exactly what is looking for. Fortunately I bought it on sale, which only made it expensive.

Don't use the clicky if you are averse to spending $$$$$.

HyBridge® Lite Tech Down Jacket

really depends on what youre using it for but yes, down does not breathe as well as these active insulation pieces (and obvs does not retain its warming properties as well when wet/sweaty/both). though if youre just climbing, a light down jacket the way you describe it is fine imho. i do find once you warm up its harder to dump the heat with down. i think these active insulation pieces are best used for medium-to-high output activities like touring or alpine climbing (and i personally love them for that).

As a stand-alone midlayer? It's rare that I use a down jacket that way.  It would have to be a rather casual day.  I just sweat too much when I'm moving.  As such, I generally use a down jacket as the second puffy in my double-puffy system.  Double-puffy at a belay?  Sure, great.  Double-puffy while moving?  Brrrrr, yeah, I know it's cold when I'm moving in a double-puffy setup, or just not moving very hard.

If your not moving, down as a midlayer is fine. If your moving and creating a lot of heat and moisture, its not great.

Hello,

If you do use down for a midlayer, use the hydrophobic treated down. You may have to refresh it every now and then.

Also using down for such will mean more sweat, and thus more washing. Your down jacket may not last as long.

Thank you

In order to keep the down inside, the fabric needs to be extremely tight faced, and fairly strong. Typically  this is achieved by starting with a very tight weave, and then calendaring (pressing between heated rollers) the fabric in one or both sides. The net result is extremely low air permeability, and typically very poor breathability.

Then, consider the fact that you need both an inner and out shell to contain the down, and you can imagine what this does to the breathability of your system.

If it is cold enough to be wearing a down jacket while moving, it must be very cold*, and so the dew point might  be inside your garments somewhere.

When you add those two factors together, you see it is not a great location for a material like down, which rapidly loses loft in humid conditions, and is nearly impossible to dry and re-loft in the field.

The other thing to consider is whether  down brings any benefit. The biggest benefit of down is how warm it is per weight, and when used as an outer layer, the fact that the face fabric is wind resistant adds further warmth.

However, in a thin mid layer, the absolute difference in weight is minimal. If you only have 2 ounces of down, even if it is 50% warmer/ounce,  synthetic would still only be 1 ounce heavier. The wind resistance of the face fabrics is of no benefit, because your shell provides that function.

So the two benefits down has over synthetic insulation are of very limited value in this use case.

*unless the windchill effect is very strong

Tjaard says all the words I couldn't be bothered to say. Good work my dude. 

We can go even further in examining the pros and cons of various moderate insulation layers: 

.Most of the ‘active insulation’ garments on the market (Nano Air, various Arc’teryx, Polartec Alpha with face fabrics from different brands and other proprietary options) do not breathe as well as plain PT Alpha Direct.

Stephen Seeber measured this on Backpackinglight, but it’s members only.

The gist of his tests for a system with a shell was:

 if you want the minimum weight for a certain amount of warmth, as well as maximum breathability, and maximum flexibility/adjustability of your clothing system, the active insulation garments with one or both sides covered face fabrics are less high performing than plain Polartec Alpha Direct.

If you think about it, it makes sense: the face fabric adds no warmth, and no matter how air permeable it is, it still reduces breathability After all, nothing brethes better than nothing. The surprise to me was just how much breathability was reduced.

So, by going to pure PT Alpha Direct, not only are you saving weight, and increasing breathability of your system, the added benefit is adjustability:

Alpha Direct has such an open structure, that once you open front and pit zippers, you can really dump a lot of heat and moisture. Garment dry time is also improved.

I don’t remember if he had tested regular fleece, but most likely, a mid thickness, low density, fleece would perform fairly similarly to Alpha Direct, just at a fair bit higher weight and hair less breathability and a touch less effective cooling from zippers. After all, Alpha Direct is basically just super low density fleece.

So my take home from his tests:

For activities where you will wear a shell full time, like iceclimbing: use  Alpha Direct, or if you want to save some money, an open weave “regular“ fleece.

The active insulation garments with face fabric(s), I use  for activities with no wind, very  cold temps and high exertion. Even there, you could get the same, or better performance from Alpha Direct with an appropriate, super breathable(maybe front only) shell. But I already have some of these pieces, so want to keep using them. Also good for lift served skiing, if you care how you look after skiing.

For moderate activity, in very cold temps, or windchill, I prefer to use a thin synthetic high loft jacket. Since this is usually over the top of other layers, either with or without a shell, I don’t think you can really call it a mid layer anymore.

Although I have a lightweight (~2oz fill weight) down sweater, for the reasons mentioned above, I won’t buy a new one if it ever wears out.

I‘ll keep using down for items with such high fill weights that the percentage difference in warmth/weight makes a decent absolute direference: sleeping bags and winter jackets.

A good source for Pt Alpha Direct hoodies is Superior Fleece, close to me here in Duluth. Super nice couple , and good prices. They take orders on a fixed date every few weeks, then do the sewing and shipping. So, just know you can’t randomly click  and get one next week. I am not affiliated with them,nor friends with them, I just want to support a local cottage maker and help people find out where to get the gear they want.

Once again another outstanding post of stuff I can't be bothered to write up. One issue with the direct is simply that it layers poorly over a fleece which is why I eventually decided against it, I was sold on alpha direct until I put it on, if it means I can't wear my eclipse I'm just going to sacrafice the warmth to weight of alpha direct. Warmth to weight is a non issue for this layer imo, you're wearing it all the time so why would you care about pack weight. I'm always wearing a wind shell as well so why would I care about absolute breathability?

In reality the test results don't paint quite the picture you would hope, I would personally like to have a polartec alpha direct with a single layer of breathable inner fabric so it can layer better, on top of the direct I can simply use a synthetic gilet for extra warmth. 

@Seb, for sure, wearing Alpha Direct over something fuzzy is annoying. I have mostly worn mine either next to skin, or over a baselayer. You could perhaps take a single side faced Alpha Direct baselayer and reverse it, but at that point, I bet you get better results from a nice open weave fleece, and cheaper too.

How much and where weight matters wil be a bit personal. For me, mid layers do end up in backpack, where weight matters most, but even on my body, all weight matters for uphill activities.

I am not sure I understand quite what you mean with not caring about absolute breathability?

thanks for the high quality info @Tjaard Breeeuwer.

i've been suffering for some time, trying to figure out the best system for me..

I run VERY hot, but of course i feel cold when static with wind breeze. Usually where i live i get 18 - 5 celcius in winter so everything i have is too hot..
the thing about using down under a shell and getting umid is so true. I've used a cerium LT under a alpha ar in patagonia, walked around town for 20 min and i was soaked in sweat and the jacket seemed to loose all its loft.

Now i have a patagucci nano air light hybrid and a TNF Ventrix 2.0 as synthetic midlayers, but even them i think are too hot...trying to use a Eddie Bauer high grid fleece as this lighter midlayer, but i wonder if the Alpha direct would be superior to my intended use..

maybe alpha direct 90gsm + light wind jacket?( maybe 60gsm would be better, but i have durability concerns)

Right now my system is something like..

15-5c Winter:

any lightweight baselayer or sun hoody
eddie bauer high grid fleece
OR

pata nano air lyght hybrid/ TNF Ventrix 2.0
lightweight windjacket

usually i just go with long sleeve sun hoody and put the windjacket if it starts raining..

0/-10c

merino 200 baselayer
nano air light hybrid or ventrix or eddie bauer high grid

Cerium LT(that now i wont use under the shell anymore)

alpha AR

so.. TLDR. would be good to ditch the EB high grid for the ALpha Direct 90gsm?(or 60gsm if not too delicate) for a person that runs very hot in general?

Philippe Queiroz wrote:

merino 200 baselayer

nano air light hybrid or ventrix or eddie bauer high grid

Cerium LT(that now i wont use under the shell anymore)

alpha AR

so.. TLDR. would be good to ditch the EB high grid for the ALpha Direct 90gsm?(or 60gsm if not too delicate) for a person that runs very hot in general?

I’d say that the first change should be ditching the hardshell (Alpha AR).  You’re almost guaranteed to roast with a hard shell on, and the breathability of everything under it becomes mostly irrelevant because it doesn’t breathe.  A wind jacket or soft shell will breathe more, but if you’re wearing a Ventrix or Nano Air they have the wind jacket built in (outer fabric layer) so you shouldn’t need anything over the top.

-10 to 0 C isn’t that cold, depending on exertion. Is your merino base layer long sleeve?  What is your activity level?  You might have too much on in general, even without the hard shell.

A grid fleece like the EB and an Alpha piece aren’t exactly the same functionality so they might not always be interchangeable.  A gross fleece is more of a base layer (it has features designed to next to skin fit and moisture transport) while Alpha is more of a mid layer insulator.  There is lots of overlap in function, though.  Just something to think about.

yeah.. Alpha AR is totally off.

merino is long sleeve, but just in case. never experienced anything colder than -10, and only used the merino in to sleep in camp..

i really need to optmize this system, it does feel that its not right, but dont know exactly why to make it better for this 2 temp ratings