insulation question

If I wore those two layered properly I say they would be warm to about 35F-40F if wearing sufficent headwear and leg coverings.

I say the two items would be as warm as each other.

I like the 100g type synthetic puffies for cold camp use. I use a Power Stretch hoodie or vest as a mid layer with a windshirt that provides as much or more insulation as the Nano Puff and the combo is more versatile and breathable. The Nano Puff is a handy-dandy layer for 3-season day hike CYA, but I agree that it just isn't enough insulation when it is cold in camp.

If you are using mid layer and windshirt, try adding a puffy vest. A vest gives good core warmth with smaller volume, less weight, and costs less too. If using down, you could carry a vest that is twice the loft for about the same weight as a jacket of lesser loft.

I just can't seem to be at peace with carrying two puffys although the ex lite is pretty dang lite and the nano puff under 12 (together 17ish). But this costs me no money , itll be somwhat versitile, and most important, should be plenty warm. I also know I have to pack space. Other than the weight of of the combo I see lots of positives but just want to make sure im not missing anything or that for some sceintific reason a synthetic over a puffy isnt as warm as common sense would seem to think. Thanks

If the outer garment isn't big enough, it'll compress the inner garment making it less warm.

Maybe, if the down is on the inside, it will get compressed more and lose warmth. Synthetic on the inside will retain it's loft better.

Maybe, especially if it's real cold – like in the midwest in the winter, if the down is on the outside, that is where water vapor will reach the freezing point and form an ice layer and since it's down, will be more effected by being wet, if the outer layer was synthetic you'de be better off

I have both of those jackets and usually take the Nano. I also use a Patagonia Houdini windshirt and take a rain jacket. Put all three on and I can stay very warm through virtually anything, especially if hiking. If it is colder than that it is normally nite and I am toasty under my quilt. So rather than take two puffys I would take a versatile windshirt and rain jacket and layer all three if necessary. All serve a different function when used separately as well, unlike carrying two puffys.

You put your windjacket under your nano and rain jacket over nano right?

I may stick with that combo and add the 6 oz ex lite as needed. (sierras washington)