Stacking Insulation vs. a bigger puffy: the rationale behind a 2 jacket system

Yes to layering for active hiking. I keep my puffy in my pack while walking, and had plenty success keeping warm with my LS merino t-shirt and my alpaca hoody. The puffy comes out when I stop or am at camp. If you plan to spend a lot of time sitting around either on the trail or at camp, a warmer puffy is a better option, but I am happy with this setup, noting that I am going to either be by a campfire or in my quilt if I am at camp and it is colder than I like to just be sitting around. Having the extra layers and the extra weight, as you have noted, is a trade I thought worth it in exchange for the versatility, with the caveats I specified above. The extra weight in this case is not an issue for me. I can save that weight elsewhere.

I think that the warmth of a jacket is mainly the insulation.  The shell fabric is just overhead.  Mainly.

You can add more insulation to a jacket without adding shell fabric.  So the overhead is reduced.

Maybe a jacket is 1.5 yards.  Both sides is 3 yards.  If the fabric is 1 ounce/yd2 that’s 3 ounces total.

If you have two jackets, you’re adding an extra 3 ounces of overhead.  If you have one thicker jacket you’ll save 3 ounces.  Approximately.

I’ve been doing 2 jackets – one synthetic and one down.

The synthetic doesn’t provide too much warmth so good while hiking.  Some synthetic in your gear is good because it retains warmth if wet – in some survival situation where I get the down wet, I’ll still have some warmth from the synthetic.

I have two down jackets, one thinner and less weight for warmer weather.

Actually, I just have vests.  I don’t like sleeves.  If the vest is a little thicker, then you can get about the same warmth over-all.  And save the overhead weight of sleeve material.

If your current (outer) jacket fits perfectly now, it’ll be tight over a vest.  Compressed down is less insulating.  Synthetic would probably be a little less sensitive to compression, but only a little, and a tight fit would compress the outer insulation a bit as well.

My opinion:  a puffy is for camp only, so dialing in performance with layers is not very important.  I’d get one warmer jacket.

I’ve read about the benefits of synthetic layered over down for quilts in cold, especially wet conditions. Wouldn’t that apply here for in camp jackets?  I don’t encounter a lot in of wet weather, but it still dominates my thinking when it comes to cold.

If it’s really in camp and you are counting grams then the sleeping bag or quilt should solve that. I spend more time in camp than I want to spend in bed so I like having jackets that keep me warm enough. I also get cold faster these days and a few extra ounces to stay warm (and dry) is acceptable. I would think the Alpacka hoodie underneath your down hoodie and rain shell over sounds good. I haven’t tried that yet but the concept would be the same with a fleece.

I often take a synthetic jacket if I think I might need it hiking because of cold and/or wet, with plenty of breathability. I then have a down vest or lightweight down hoodie to wear in camp assuming the inside of the jacket is dry.

I’ve come to the ‘one big puffy’ conclusion–but I hike in Ca. where it'[s pretty warm and dry. Down is by far the lightest, most efficient insulation. With a big puffy I’m able to leave at home at least one layer that I used to take, maybe two, and I’m warmer. So I end up saving ounces. I’ll wear the puffy in the cold mornings while packing up and then it comes off as I start the hike. sometimes I’ll hike a bit cold with just a thin layer and shirt but as soon as the sun strikes I’m fine. Or I wear my rain shell for some warmth. I run cold so the puffy goes  on in camp as soon as the sun sets, or earlier. In other words, I found the ‘versatility’ of carrying several layers to micro manage a few temperature scenarios to be not worth it.

The big puffy is a fabulous pillow too.

I go the layering route, and it’s worked pretty good for me. Long sleeve hiking shirt (Motus), hooded fleece mid-layer (MEC T2, which I’ve only had to use a few times), hooded synthetic puffy (Montbell Thermawrap parka). If it’s colder than that I don’t take off the silk base layer that I use for sleeping. That mix has served me well for mid Spring to mid Fall outings in the Pacific Northwest.

. MIKE CLELLAND VIDEO TUTORIALS third video from the top is on clothing

It would seem that the dead air in between two layers Provide some insulation value in itself. Does anyone have any data on this or even any anecdotal information in either direction?

I’m in Austin Texas, and we had never even heard about the cold weather until last week. So I’m probably totally clueless here.

It’s not just the weight of the jacket or parka, sometimes it is also about the fit.
If you layer clothing then that outer layer has to be a much bigger cut than the inner and this looser style isn’t always easy to find.
I have a lightweight layering system for warmer weather but as pointed out already 100 grams of insulation is a lot warmer than 100 grams of shell fabric.

My logic is aligned with Jerry on this one. Most of my cold and snow is in the Smokies, which is always a study in weather variations: it could be warm, it could be 35 degree rain,  it could be 32 degree sleet or freezing rain, it could be snow and 0 degrees…within a short timeframe.

When I’m moving I’m sweating…no exceptions and I would never wear down on the move. Insulation in camp is a different matter. I have a Borah down sweater and pants, and an additional NF Microball hoody for insulative layers. There are much better synth options out there but the strategy remains:  keep some sort of synthetic insulation to deal with H2O.

A lot of great comments so far. I have my outer puffy layer cut pretty loose to fit over top of everything so it acts like a belay parka. It may be wise to add an over-sized windshirt on top of that puffy so that the wind does not rob me of my hard won heat. Where I hike, wind is a regular companion and although campsite selection is critical here, I may nonetheless get some benefit from the windshirt as terminal layer. My current rain jacket, although sized up, is not loose enough to fit over the down jacket, so I wear it underneath (again, think a climbing action suit/belay parka approach).

If you have two jackets, you’re adding an extra 3 ounces of overhead.  If you have one thicker jacket you’ll save 3 ounces.  Approximately.

Absolutely. That is my thinking.

It would seem that the dead air in between two layers Provide some insulation value in itself.

This too, was part of my question.

I think the situation where I struggle most is during early/late shoulder season trips with short daylight hours where the temps are not low enough to warrant my winter parka. I am often hiking up until dark and not at established campsites, so I usually try to find a campsite around sunset. Then during the long evening after dark I get a bit chilled as I don’t want to retire to bed right away and would rather hangout a bit in camp as Bob said. I’ve never had this issue much before, but I’m in a new milder, dry, desert climate where temps are higher during the day, but the days are still short and nights are colder. I’ve also been solo hiking a lot more and using a tarp, so there may be a morale component. My hiking tapers off around 5-6pm and my camp chores take under an hour so I have a couple hours to kill before bed.

Sounds like I should try using my sleeping bag as a blanket outside of the tarp to hang out in instead of getting a warmer jacket for now. It seems silly to let it sit unused while I may be cold sitting outside without it. Do people find this is practice hard or abusive to thin UL fabrics?

Russ: do you put your synthetic as the terminal layer?

That dead air between layers was the point I was trying to make about garment fit.
For me it seems to work better when my Uniqlo UL down parka is topped by the Patagonia Nano-Bivvy, it didn’t when it was just the normal Nanopuff a size larger
But my Patagonia DAS is warmer than the combination for the same weight
The DAS is my go to winter static layer because it’s a cold wet snow here and it is still in very good condition

yeah, the dead air between layers adds some warmth, hard to say how much

If the inner garment is sewn through then the dead air is probably the same amount as if the outer garment was just a windshell.
Looking at it from this POV then it would not make much sense to use a fully baffled warm garment as part of a layering system of static clothing, sewn through with at least 100 grams of good down might be a better starting point, although being an XXL in jackets I’d be looking at more fill than that for my own use, probably 150+ grams.for an Australian winter

Dead air can add a tiny bit of insulating value, but I’m not seeing where you get dead air between two garments.  More like air in a bellows.

the garments are sort of wrinkled or whatever, not perfectly flat against each other

so, some air space and some warmth

Since I’ll bring a rain shell no matter what, I make sure that it can fit over my large puffy. that takes care of convective loss from the puffy. It’s extraordinarily warm.

so, in camp: capilene shirt under my hiking shirt, puffy, rain shell if needed. In early season I’ll bring an additional thin fleece layer. This last adds some versatility in the morning. I don’t bring a wind shirt because the rain shell serves the same purpose, more or less (and yes I know it doesn’t do exactly what a wind shirt does but it’s close enough.)

the puffy is warm enough to just end all contemplation about whether three thin layers trap a bit of warmth or not. they’re not needed, end of discussion with myself. AND the weight saved from not bringing an extra layer compensates for the weight gained in bringing a large warm puffy. Actually the warm puffy minus a layer is lighter than bringing two or three extra layers and leaving the puffy.

p.s. the “big puffy” means something beyond a lightweight down jacket or vest that requires an extra layer or two to compensate for it not being warm enough on its own.

p.s. the “big puffy” means something beyond a lightweight down jacket or vest that requires an extra layer or two to compensate for it not being warm enough on its own.

What do you use as a “big puffy” and in what conditions normally?

Can anybody speak to using a sleeping bag for additional warmth when in camp? I have a mummy bag, probably not ideal, but will try it this weekend.

I have a North Face synthetic vest that I throw in with my Montbell light down puffy and a light WP jacket like a Helium in shoulder seasons and they work extremely well together. For me, vests are fantastic for hiking, I can easily modulate heat minute by minute, keep the core warm but not overheat/sweat.

Layering is what I do because I can’t afford a new down parka and my old parka is far too warm for here and being a pretty specialist garment not really suitable for general walking or ski touring anyway, and I’m a bit fatter than I was when I bought it. Sometimes we do have to make gear choices based on cost and income and UL/Extreme Lite doesn’t come cheap.

Bothering to comment for the first time..

This is one these questions, where I think it’s useful to make a separation between “what’s optimal” and “what’s practical to own”.

For a stop layer, I don’t think it’s practical to have multiple pieces. More hassle etc. So, ideally one would have puffies of various thicknesses for various trips.

..But that leads to lot’s of purchases. So, rather one might want to buy few pieces which fit most of the usecases, and combine well to cover more bases.

I have one Haglöfs piece I’m happy with to late Fall, but it’s too warm for summer trips, and not warm enough for actual winter. I don’t winter camp that much, so it would make sense for me to get lighter puffy for summer use, and combine those two for winter use.

Eric – If wearing together, the synth insulation is on top, and I have a rain shell that will goes  on that if necessary.  Add to that the base layer undies and you can take it pretty low.

Another added benefit with the down sweater and pants is the way it can supplement the sleep system

Layering and flexibility works best for me.

Another thought and then I’ll shut up. I did a 6 day trip in the Smokies the last week in January that began with 2 days hiking in shorts, and 4 days of ice and snow with a low of a few degrees above 0.

Fast forward to Gear Swap where I’ve seen a couple of expedition puffies and shell combos in an XL at a deep discount….Oh man, I THINK I NEED THAT! And then I thought back and concluded that I never suffered and already  had exactly what I needed and it worked well. Now my hands are a completely different matter!

Interesting comments. My main takeaway is: there are as many systems as there are metabolisms and hiking styles! Definitely a personal choice.

So, maybe I’ll bring it back to some specific gear to make it easier and more concrete. I feel that I don’t want to add a fleece to my lightweight down, but would rather switch it out for something a bit warmer. I’ll simplify this to two choices: Arc’teryx Cerium LT (found on sale for around $200 CAD) and Cumulus Incredilite Endurance (found used for $265 CAD).

The cumulus is warmer by a decent margin (40g of ~900fp down) and is 40g heavier, too. Cerium has 102g of 850fp down PLUS some synthetic (I have mixed feelings about hybrid structure) so it will be a bit warmer than another identical jacket with 102g of down in it.

I’m trying to figure out if the Cumulus will be too warm to completely replace my summer layer as my full-on 3+ season jacket (it is about 135g heavier than cerium sl) and/or whether the cerium LT will not be a significant enough upgrade from the 52g of down + synthetic in my current jacket to warrant the switch.

The cumulus is more expensive and a bit heavier, possibly verging into the overkill category, but it would eliminate completely any qualms about not being warm and is still well under 350g. It may also serve double duty as a summer alpine jacket where the cerium LT may not.