Calling outdoor experts... Winter jackets - down vs synthetic.

[413x]

I own quite a lot of winter gear. But my camping hobbies have required me to have a outer layer for walking and one for being "still" at camp.

I get very very warm even walking.
Warm enough to only need 2 layer leggings on bottom A merino base and an outer synthetic mid layer and that's it.
Now when I stop I can get quite cold. Cold enough to need a thicker layer. Which I can't wear walking.

I've been trialing some new items. I already own a rab xenair alpine. (primaloft). But I assumed a down jacket would be better.

So I purchased a rab microlight alpine. I expected this to be warmer despite being a thin down jacket.

Tonight I went out in no wind 1c for a walk and felt a tad cold in the microlight (down). I went back home and got my xenair (primaloft) and it was warmer!

This has thrown me a bit. I expected the down jacket to be better even if thin. And wonder what the purpose of the thin down jackets are.

I've not really used a down jacket much to date but can any out door experts let me know if these thinner down jackets have any place in a kit bag?
If it was windy would the down jacket offer more for example?

 

[413x]

Down weighs far less than syntetic for a given insulation. It depends somewhat on the jacket construction and light down jackets are probably stitched through so you have lines of zero insulation, rather than box baffles on thicker puffer style down. The advantage of synthetic is when the weather is damp - like typical low-med level UK winter conditions when its drizzle and mist. If you are above the clouds and its cold dry and crisp then down excels, but if it gets damp it clumps up and losess warmth. Microlight down under a waterproof shell works well if you dont sweat into it too much, synthetics (like your primalofty which is excellent) are much more suitable for damp, or the risk of getting damp. For basecamp sitting around a primaloft would be my preference, really cold alpine style (stable cold conditions in scottish winter would count) down and a shell just in case would be good.

See this is what I was expecting.
Its a dry crisp cold still day here. And I expected the microlight to be warmer.
But it wasn't.

Its made me consider is there any need in the UK for a light weight down jacket?

Like you say its more often damp and cold here. And in this weather I take an arc'teryx atom, arc'teryx Proton or this new xenair with a waterproof shell.

Also. The microlight is a heavier jacket than the Xenair.


I seriously think I must either be wrong. And maybe I walked faster in the Xenair. Because otherwise.

Xenair (primaloft) is
-lighter
-warmer
-more ventilated
Than the microlight (down)