Lofty Fleece Layer

Justin, I have to fundamentally disagree with you…

Regular fleece will always be warmer than grid fleece if the fleeces are the same weight. One traps air, one moves air. A grid fleece will be colder because it lets air flow.

Adding a grid removes fleece material in a grid pattern. It doesn't make the garment somehow warmer by magic.

If the grid fleece material weight is higher than 100wt or if it's cut for a closer fit, that's different, but you cannot say that grid fleece is warmer because that defies physics.

Hi Max, there might be some limiting assumptions. First, I said in combo with a wind jacket. Also, those voids in the grid fleece are designed to trap air and does so well in combo with a windjackect. Remember, its air that is the insulator, the trick is to keep that air from moving, and the less material you can do that with, the better.

Without a wind jacket, the regular fleece will be a bit warmer especially if there is any wind, or fast body movement.

Currently I have 3 grid fleeces, a Pat Cap 4 hoody, a Terramar hoody which is kind of like r1 material and a thrift store grid fleece that is also like the r1 stuff. For other fleeces I have a 100 and 200 wt air core fleece, and a reg 200 fleece vest, and a regular 100 at shirt.

Speaking from experience, with a wind shirt, all the grid fleeces feel a bit warmer than all the 100 at fleeces at less and similar weight. But also consider this, because the grid fleeces move moisture more efficiently, when sweat is involved they will be warmer faster. So less weight, more breath ability, faster drying, and similar insulation in combo with a wind jacket, not sure why one would choose reg. fleece except to save money.

I have very serious doubts that the voids in grid fleeces trap more warm air than the fibers of an equal-weight fleece, even under a windshirt. If both fleeces are under a windshirt – and all other conditions are identical – I think the regular fleece still must be warmer. Between every fiber, there's air, and without voids for a grid, that air is stationary and warm.

Look:

Picture lightly blowing on material like that. Congratulations; you just pushed all the warm air around and mixed it with cool air. Windshirts do a good job of blocking wind and preventing convective heat loss, but they're not a closed system and they don't turn your entire torso into one giant baffle. There's still air movement. Only fibers or feathers are really going to secure warm air, and for that, regular fleeces and other insulations without voids do better than something like grid fleece.

I know the perfect example: sewn-through baffles vs box baffles. Which is warmer?

The voids in a grid fleece shouldn't hold any air. Air should pass freely; that's why they're more breathable.

I don't see an ounce of anything to convince me that grid fleece is warmer in equal material weight and conditions. In fact, i'm reasonably certain it's the exact opposite.

As for moisture, I think grid fleeces win there. Active use changes things. For my purposes, though, which I outlined in the OP as being a throw-on layer when stopped and a sleeping layer, it'll always be a superior choice. Always.

There's a boundary layer of maybe 1/2 inch around every surface that provides insulation much the same as inside the insulation. The fact that there is a grid of indentation won't effect that much. The air inside the indentation won't move around so will provide the same insulation as if there was insulation.

If it's windy, the boundary layer is much reduced, but then the air will blow through the fleece everywhere so it's insulation will also be reduced. If you have a shell outside, then the indentations will cause no loss of insulation compared to if it was solid fleece.

As for moisture, you don't want to sweat if you want to maximize warmth. Doesn't matter if the water is wicked away better, you still lose heat. What you want, is to not overheat and require sweating to cool off. The solution is to not have superior wicking, but to take clothes off until you're not over-heated. I think all this "wicking" talk is just marketing spin to sell gear. But maybe that's over-stating things : )

Jerry, I more or less agree with the sweating part, BUT it seems no matter what I do, my back sweats because of a pack. In lieu of that, would prefer something that dries faster, even if its just my back which is sweating.

wicking does matter …

for climbers you cant always just take off another layer mid pitch, or even on belays if theres wind blowing all over the place … beyond the obvious danger of doing that in the middle of climbing … youll waste too much time faffing around, lose heat each time you put on and take off a layer, and risk dropping or having them blown away …

for sports that dont allow you to always take on/off layers in the middle of activities … and require bursts of high output … a bit of sweating is a fact of life … you need to find the balance point between a bit of sweat, and it being too cold … youre never really at the equilibrium point

now walking … people can do whatever they want

remember these grid fleeces were originally made for CLIMBERS and other such folks … not for walking … its made to be used with the "action suit" concept …

;)

Max, see Jerry's reply below your last, he explained it well. Also read up on fishnet base layers, similar principle.

The Norwegian military requires use of fishnet base layer as a standard, the Norse know cold weather very well.

I would venture to say that in combo with a closed up wind jacket, my polypropylene fishnet shirt has similar warmth as any of my 100 wt. fleeces with better comfort and moisture management.

There are some good articles and posts around here about these. Again, grid fleeces work on similar principle involving void air spaces.

The grids on Power Dry create a lot of air pockets and allow moisture to move on out to the surface. In many ways it is like net base layers. I can see where maximum moisture transfer will come from direct skin contact, with thinner base layers being more efficient than thicker ones. But you still get trapped air and you still get moisture transfer, as much from the open spaces in the grid as from wicking via the fibers.

Fleece is most useful in wet/cold/humid conditions from the high 20's into the mid-50's F, like cold rainy weather. If it is freezing, you want warmer, loftier stuff and rain isn't an issue. Whether you want down or synthetic fill is a whole other discussion.

With that in mind, layering fleece past base layer and a single fleece garment is inefficient and heavy. If you need two significant layers of fleece plus base layer, you should have a puffy instead. There's no way I would be wearing multiple layers of fleece while active. I could see a heavier base layer and perhaps one fleecy midlayer for light activity in sub-freezing weather. Above freezing, no way. So why would I have multiple fleece layers in my pack? Never have!

Back sweating? I hate it when it runs down and gets my shorts wet. Above about 40 or 50 F, if I wear anything I'll sweat. If there are bugs or sun then I should wear a long sleeved shirt regardless.

Plan A is wear thin shirt and add WPB jacket if it's raining. If it's below 40 or 50 F shirt won't get too wet so it dries quickly when stopped.

Plan B is to have thin shirt that doesn't absorb much water. Since it's warmer, I won't get chilled and my shirt and shorts will dry quickly.

All things being relative…check out the winter trekking site, for more extreme cold, those folks recommend more than 1 layer of fleece (or fleece in combo with an insulating wool layer). Granted it doesn't seem like too many of us are likewise going out in -20*F weather… so your advice is still mostly applicable Dale.

Huh. Consider me enlightened. I'm still slightly skeptical about grid fleece, though, and considering that my fleece usually goes on above my wind shell, it's probably not best for me.

Patagonia R1 has got way too many zippers and doodads and pockets, though…

"Granted it doesn't seem like too many of us are likewise going out in -20*F weather… so your advice is still mostly applicable Dale."

I've got over 50 years experience with cold and wet, and I've done a lot of cross country into the teens F, but not the sub zero stuff, and no thanks! :) if it is that cold, a stout cabin and a fully stoked wood stove are indicated!

I'm talking about 3-season weather in the Cascades and Olympics. Fleece is good stuff when everything is soaking and your sweat has nowhere to go. Wearing multiple layers of fleece and trying to move uphill with a pack on? Nope!

If a base/fleece/shell aren't cutting it in camp, it's Puffy Time, not excluding getting in the sleeping bag.

I'm out all the time in 0º, and I would be out in -20º if it ever got there… I did cold weather cycling trips last winter when it was in the single digits and single negative digits with windchill (and cycling windchill is even lower!). I did Camel's Hump with the expectation of -30º, but it only got to about -5º. Booo…

To be honest, I didn't spend a lot of time thinking about fleece on any trip last winter. I just wore it. I had some cheap Columbia fleece and it was mostly fine.

Now, unlike Dale with 50 years of experience, I have literally less than two. My backpacking life is interesting because of how abrupt the line is between no activity and near-constant activity. I'm sure i'll be going out with a grid fleece at some point and aggressively testing it's properties.

Doesn't make me any less happy with this Micro-D, though.

Oh look, I drifted back on topic! A Max Dilthey BPL Thread first!

If it works for you, then no reason to not use it. I sometimes get caught up in the over left brain, over analyzing, over thinking, theorizing, weighing etc, but to some extent that's because I can't get out as often as I use to because of my job.

Sometimes its better to not think, etc and just do and be. That balance can be hard to achieve especially when subjected to the gravity pull of BPL. I find I go in cycles where I think very little about gear and then other times too much.

Guess I'm saying, its a good thing you are happy with your micro-d fleece. Grid fleece might be a bit better in some ways, but not enough to significantly change your life or outdoor adventures in most cases.

Below about 20 F it gets more difficult to keep your water from freezing

I go year round in Oregon and Washington. There are times it gets colder so you have to consult weather report. It's supposed to go down to 18 F the next few days in Portland but it's like the coldest it's been for three years.

Yeah, don't over analyze. Lot's of good ideas that will work for different people in different situations. Use what works for you.

>.P.S.
>>I thought the fleece v.s. shelled synthetic insulation debate was long ago settled in >>favor of shelled synthetic jackets.

Mmm..not really IMO. :)

I find if I wearing my warm garment all the time, the conditions warrant fleece. Fleece breathes well, dries out quicker and performs better in both cold and dry and cold and wet conditions vs a puffy layer I find.

Basically, if it is cold enough to wear a warm layer, I find that the puffy layer will be damp- be it my own sweat or the outside moisture. (Like the ski touring I will be doing this weekend. Brrr! )

Now, for three season backpacking when I am carrying my warm layer and throwing it on at breaks or camp, I prefer the puffy.

We had a a similar discussion earlier:
http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=75720

(To quote Tricky Dick Nixon)

Dale, I meant shelled synthetic PUFFY jadkets, not shelled fleece.

Sorry, as a former English teacher I should have made that clearer the first time around. I have since corrected it in my 1st post.

Max, You have a good point about lighter (100 wt.) fleece and layering. There are conditions where that and a shell are perfect. I've XC ski trained for racing in 10 F. weather with 100 wt. fleece beneath a nylon wind jacket and been comfortable… as long as I was moving briskly.

And, as you say, there are conditions where a synthetic puffy, with or without a shell, is truly needed.

BTW Max, are the fibers in your fleece jacket hollow? Some fleece (or heavier pile) has that feature and it is suppposed to be warmer, sorta like deer and elk hair.

"Dale, I meant shelled synthetic PUFFY jadkets, not shelled fleece."

Is a "jadket" some sort of Elizabethan clothing? No, that's a jerkin :)

Have you seen an unshelled puffy jacket? :)

I proposed making a synthetic fill jacket with a conventional lining and a lose scrim or netting on the outside with the idea that it could be used with a windshirt to form the outer shell, like a 3-in-1 jacket.

Hey, you honking at ME?

max – the example you chose is the exact opposite of the point you're trying to make. that goose would be cooked if it didn't have both a shell and insulation layer. the contour feathers, the ones that cover a bird's body, act as a highly water resistant/wind resistant breathable layer. the down, protected by the *shell* of the contour feathers, provide the insulation. this analogy is a bit simplified, but generally accurate.

My example was sewn-through baffles versus box baffles. The goose was a drifting off-topic piece of chaff. Though, I don't think it'd be inaccurate to say that my goose is usually cooked the moment I talk gear theory with more intelligent people. Page 2 has me schooled on grid fleece.

I know that I feel warmer with grid fleece than non-grid fleece and not that stuff that was alluded to in the picture, the more puffy grid fleece.

Dale, "I proposed making a synthetic fill jacket with a conventional lining and a lose scrim or netting on the outside with the idea that it could be used with a windshirt to form the outer shell, like a 3-in-1 jacket."

Dale, in a very loose sense, my idea is sort of like that or rather, i'm looking for similar end results. I'm just waiting on some of that very breathable 1.1 oz ripstop nylon. Going to make a simple vest, just one layer of fabric on the back, then on the front, Apex sandwiched between two layers of the very breathable rip stop.

The concept is similar to the new Polartec Alpha material and why they designed it.

When you really increase the breathability of synthetic loft insulation, it can dry much faster. The problem with a lot of synthetic fill jackets is that they are using shells and linings that really should be on Down. It's like having two windshirts together, with a layer in the middle.. about as far as opposite of breathable as you can get.

But when you use something like Apex, you can use very breathable material. Apex is also more durable than Primaloft, plus doesn't need to be quilted or have baffles.

I think it's a really great combo. The only problem with using ripstop nylon is that it doesn't move moisture very well. It would be great if i could somehow "brush" the inside lining fabric without damaging it, in order to improve moisture movement. Almost wondering if i should use the Polartec Power dry high efficiency baselayer fabric for the inner and then the ripstop just for the outer front core area? It would increase the breathability even more, as well as speed up moisture transfer…

Think i will make two vest, one all breathable ripstop nylon/Apex, and one a combo of the PPDHE/nylon/Apex.

If 2.5 oz Apex is about equal in warmth to a 400 wt fleece then i probably would only be able to use this on the very coldest days around where i typically hike (talking probably around 10 degrees F). If i can use some of my vacation time, would love to try it out in the White Mountains of NH in the winter.

There is a guy on EBay selling PPDHE base layer material. 2.3yds for $15.00

I've never made my own items before, but I like your idea. It seems to make sense in my mind. People complain about condensation/moisture management issues in bivy sacks made with M50 or M90, so one would expect similar moisture issues when using two layers of the same fabrics to build an insulating mid-layer garment.

I wonder how thru-hiker's Kinsman pullover kit, or their "Minima" vest kit would perform using PPDHE fabric as the inner.