Sorry, I know this has been gone over a bunch. Somehow I've researched myself into a tight circle. I've read Richard Nisley's amazing charts on iclo etc. However, there always seems to be some conflicting evidence within all this info.

So my question is this. I'm debating whether or not to add a synthetic insulation layer to my kit or not. I'm looking at 100 gram Primaloft 1 insulated vests and am wondering how much warmer if any they will be compared to 200 weight fleece which I already own.

Currently, I could combine a MB ex light with a 200 fleece hoody over it. Would I be better of with a 100gm PL 1 insulated vest in place of the fleece for roughly 20 degree wet evenings? Should I not worry about the wet and take my MB Alpine Light Parka instead?

Under/over all of this is the following:

180 merino Hoody
9oz Rab Alpine wind shirt
Rab Kinetic rain jacket
hat, gloves (sorted)

Thanks and sorry for the long winded question.

Edited by ojsglove on 09/07/2012 21:56:57 MDT.

1. itll be warmer than 200 weight fleece

2. therell be less faffing around ... when you stop you put the puffy over everything, so size accordingly

3. if you are truly soaked fleece is better ... as synth or no synth, the puffy will freeze into an ice ball at 20F ... so dont get it soaked

4. use it as a belay jacket, not something on the move

5. for that purpose for 20F, id personally use something with 150 g/m + of primaloft one or the equivalent of lesser insulations

Thanks, Eric. I always appreciate your insight here.

I really only see 200gm belay coats next would be the Pata Das at 170gm then 133gm Rab Photon. Is there something I am missing in between? Brand not really mattering. I am not familiar with synthetics and am surprised 150 gm PL1 would only get a person to roughly 20 degrees. I was hoping I could combine some lighter synth with down to mitigate the weight and bulk.

Thanks.

i combine my MB EXL and an atom LT to reach around ~20-30F ... more or less ...

a lightweight down jacket under a synth is a bit more complicated but provides

1. excellent moisture management as and condensation will go to the outer synth layer, and the outside elements will affect the outer synth layer as well ... if you have a surplus of insulation you can actually dry light down jackets under a synth layer ...

2. flexibility ... often for quick stops on the move you dont need the full puffy ... just use the synth, and use the down in camp under the synth ... this protects the down again, as it stays protected till camp ... also if its very cold or you are moving very slow, simply wear the lightish synth layer on the move

3. when sleeping, you dont really need puffy pants for the legs, simply use one jacket for the upper body and another one as a blanket for the lower body ... better distribution

4. redundancy ... one of the jackets gets soaked, blown away, torn, you got another ... wont be pretty but youll live

the disadvantage is that it costs more and its not as efficient as a pure down jacket ... and its more stuff to deal with

a 100g/m hooded jacket with the exl would be good for me down to 20F ... you wouldnt be hiking in it very much though

just to add ... i also use the same system with my $50 EB downlight vest and $19 dollar old navy synth puffy ... best value ever IMO

Edited by bearbreeder on 09/08/2012 00:09:03 MDT.

Eric has made some very insightful suggestions. Please add your experience.

Thanks!

Fleece is maybe 10 times heavier for the same warmth as synthetic

Maybe if you need just a little warmth when you're exercising in cold weather it would make sense?

But for hiking even down to 20 F I just use base layer, WPB jacket, and if I'm cold I'll just walk faster.

Thanks Jerry.

I was really asking for at rest in camp. I should have been more specific. I'm like you, just a base layer when on the move even at very low temps.

To be even more specific, should I just stick with my MB Alpine Light Parka if 20F low and wet weather or is that going to be unreliable even if I'm careful about moisture affecting it. It does fit under my rain jacket.

Thanks again.

What loft?

Maybe 1.5 inches for 20 F.

Maybe a little more - but you could always get into your sleeping bag

If you're in camp you shouldn't get wet from sweat.

Jerry,

Not sure about the loft in inches but it's 4.7oz of 800 down. Plenty warm at 20 degrees and dry or snow and cold. I just wanted to know if the humidity or rain at a bit warmer temp would compromise the coat to the extent that I should really consider a synthetic insulation for wet camp conditions.

Retiring to the bag is always a fail safe. It's down also but it's exposure to moisture would obviously be much more limited.

I've never gotten my puffy so wet as to be concerned about it. Even when it has been damp it still keeps me warm.

I intentionally carry one heavier than I need because the only time it gets used is in camp when I'm inactive. I'd rather carry a couple extra ounces of down and be plenty warm than save 4-6 onces on my carry weight and be borderline warm.

Thanks, Kevin.

Given you are in WA I'll take that as sound advice. Seems I'll be saving some money by not investing in a new coat!

I've used down vest in wet under rain jacket when it was raining and it worked okay

I usually use synthetic even though it weighs a little more, mostly out of inertia

There have been times my rainjecket has failed me and if I had been wearing down underneath it wouldn't have been so good

"Fleece is maybe 10 times heavier for the same warmth as synthetic."

I know the research in your article bore this out Jerry, but other data (Rrichard's among them) as well as my own experience do not agree. Variations in the shell fabrics which synthetic necessitates complicates things, but my apparent experience has been that 8-9oz/yard hi-loft fleece provides comparable warmth to 60 grams/meter (or ~2 oz/yard) synthetic fill. Of course, the calendered, rather air-impermeable fabrics most high-end synthetic coats feature no doubt add to the warmth under many circumstances, and that needs to be added to my aforementioned conjuecture.

Applicability is another matter. Synthetic is valuable for being lighter and more compressible than fleece, and much more resistant to humidity than down. It's fairly easy, even under difficult conditions, to keep a down insulating layer minimally exposed to precip, and thus dry. It's harder, while doing a multi-day trip under the same circumstances, to keep the down from collapsing due to exposure to humidity, mainly that generated from within.

20F weather won't be wet. There may be precip as snow but it won't be sloppy stuff at 20 degrees.

I use 100g synthetic for my rest/camp insulation and I would want a full jacket with a hood at 20F. I would add that to base and mid layers with beanie and gloves.

When under way and walking up switchbacks in 20F weather I would want a mid weight base layer windshirt , beanie and gloves. I would use light soft shell pants and maybe silk weight long johns on the bottom side. If it is snowing hard and sticking to my shell, then I would use a rain shell. What you don't want to do is to over dress and get your base layers sweat soaked. I would have the puffy handy for stops

It is really different when you are exerting and have a pack covering your back. It is surprising how little you need when working hard. Cross country skiing is much the same. You want stuff that will cut the wind but it must breath and can be vented easily-- full front zippers, pit zips, etc.

Temps from 32F-45F and wet can be miserable and I would still like the 100g jacket in camp A vest would be okay at the upper end of that range with a mid layer hoodie and rain shell.

I think of 200w fleece as wet day hiking stuff where you might add it under a rain shell for rest stops or light exertion. I would wear the fleece under my puffy insulation. Wearing it over would compress the puffy stuff and the shell layers of the puffy would help trap warm air in the fleece. The fleece breathes better too.

In camp I would be wearing all layers for setting up shelter or meals. At 20F and snowing, I would be getting in my sleeping bag pretty quick. Time to read or listen to the radio!

Edited by dwambaugh on 09/11/2012 11:51:38 MDT.

If the expected lows are around 20F, than highs could very well be damp, drizzly 30's, leaving you with a near 100% humidity as the temperature drops as well as very wet snow, grass or brush on the ground, even below freezing.

My choice would be:
For a short trip: bring the Alpine light, it will be your warmest layer with the least weight. You stated you can wear it under a shell to keep it dry from precip and the extra loft will compensate for any loss from humidity on a short trip.

If it's a longer trip, bring the thin down and fleece if expecting very cold daytimes or very wet conditions to be able to wear it while hiking, and to be more failsafe.

Bring a light down and synthetic puffy if expecting only moderately cold and wet weather, as described by Eric.

David - I've never seen any other data on fleece warmth which is one reason I measured it. I'de be interested in seeing it.

regular 200 wt fleece weighs maybe 8 ounces / square yard and there's no way it's anywhere near as warm as 2.5 ounce / square yard Apex or other synthetic. I have a vest out of such fleece and another out of synthetic and the synthetic is way warmer in my use.

What do you mean by 8-9 oz/yd2 hi-loft fleece?

Again, I'm not disagreeing or anything but there's little data to compare warmth of fleece and synthetic (and down for that matter).

I've always thought that the positive attributes of 200w fleece were breathability/moisture transfer and performance in wet weather. If soaked, you have a chance at getting it wrung out and dried. You can wear fleece alone or with a wind or rain shell. Comfy to sleep in too. It works great in conditions above freezing where you have high cold humidity, with added perspiration from exertion--- exactly what I experience in shoulder and winter conditions in the Pacific Northwest at lower altitudes, say 45F, 95% humidity, intermittent rain, no direct sun, and steep rough trails. A fleece vest or sweater will keep a cold shell off your base layer, transfer moisture, and trap some warm air.

With down or polyester fill, you can certainly get more loft, but you carry two layers of shell in the the deal and that encapsulation makes it much harder to dry in the field. You have a prayer of drying polyester fill and need to pray if you get the down wet.

Odd how everyone will reach for a fleece beanie, but want some skinny fluffy layer when they are also carrying a windshirt. A hight loft fleece plus windshirt equals or exceeds something like a Thermawrap or Nano Puff in breathability, warmth, durability, drying in the field, cost, and versatility. It will keep you going in conditions that will turn a thin down garment into an expensive useless lump. If you tear a fleece, it won't leak it's innards and can be easily stitched up. It will weigh a bit more and won't compress well for storage.

Move below freezing and high dry climates and down becomes much more useful.

My $0.02.

I agree Dale on secondary factors favoring fleece - doesn't matter if it rips, good if you just want a little warmth while exercising,...

I'm not so sure about being better if wet, but maybe...

I wear a fleece vest all the time. very comfortable. But not when I'm backpacking when I need more warmth and want to minimize weight.

I wear a fleece beanie while backpacking, but it's such a small area the weight doesn't matter

I'd have to say my experience matches Dale's in pretty similar conditions. Cold rain and wet snow in the 3-4 degrees above and below freezing are a great test of gear.

The advantage of fleece that I have experienced many times is that it can be VERY wet, while YOU stay dry. I have been amazed to reach under my fleece which has been dripping wet and find that the inner side of the fleece feels completely dry. Andy Kirkpatrick suggests this is due to the capillary action of the fleece. Whatever the reason, I think this 'dry against the skin' function increases the value of fleece over what it's weight and drying times might otherwise suggest.

Thanks for all of the replies everyone.

There are some good deals on synthetic insulation right now which is what has me asking. I'm still on the fence but trying to reject the shiny new object syndrome. Think I'll probably stick with my MB Alpine Light Parka and take a 200 weight fleece as back up in case things turn upside down. Oddly, I have more experience in snowstorms than rain.

Any other advice is welcome and thanks again.