Originally Posted by MAD777
Here's a partial answer. The 5oz. Climashield should take you down to the mid-40's comfortably.
Originally Posted by tammons
I find that my GG 1/4 pad is good to about 45-50dF.
The 5XP under quilt say to 45 dF
1 layer of IX should boost it 10dF.
So 5XP + IX = 35dF ??
5XP + IX + 1/4 pad = 20dF ??
This either shows how much individuals can vary, or how much varying conditions can make a dif, or how much dif there can be between brands and designs of UQ. IOW, with any UQ, a perfect fit is required ( maybe not counting a Pea Pod or HHSS which are sort of UQs, yet quite different from most UQs )
So why do I say all of that? Because I was quite warm one night, into the mid-high 40s ( don't remember exactly), in high humidity. With tarp pitched high and wide ( but no real wind ). Camped right next to a lake. And last fact: that was with 2.5 oz of CS XP in the original version of the torso size Warbonnet Yeti. With no fleece or other layers.
Also, the human furnace Cannibal is on record for having taken the same UQ, but with 10 oz of CS XP inside, to minus 11F and plenty warm enough. And I don't think he had reached his limit quite yet. So that is ! 80F worth of insulation, or 8F per oz. So cut that in half to 5 oz should ~ = 40F of protection, 70-80=30F based "extrapolating" from Cannibals experience.
Doing the same from mine with 2.5 oz: 70-45= 25F of protection. If you doubled that to 5 oz and IF that double insulation, you'd have 50F, or 70-50= 20F for 5 oz. Which coincidentally, I'm fairly sure that is how ThruHiker rates 5 oz of CS XP, assuming all perfect as far as drafts and such.
In a well sealed bag with good ground insulation
clo 2 @ 40 deg
clo 4 @ 20 deg
clo 6 @ 0 deg
There are a lot of variables in play that can have a big impact on that chart: use it without blinders.
Quilts have trouble below freezing. Make sure you design in a good way to seal it up."
( 5 oz XP @ .82 CLO per oz = Clo 4.1) EDIT
; notice also, his CLO calculations for 2.5 oz = 2.05 (2.5X.82CLO per oz=2.05) and rule of thumb being CLO 2 = usable to 40F. So the furthest I have pushed that CLO of 2.05 ( my Yeti with one 2.5 oz layer of CS ) is about 45, plenty warm not even wearing fleece. Just about as calculated.
But, again, there are so many variables, and fit, gaps and drafts are a huge variable. On threads over at BPL or Whiteblaze ( not sure which ) people using XP TOP quilts had much poorer results than Cannibal and I did with those Yeti UQs. I think that is probably due to poor drape compared to down. But if your quilt fits as well as my differential
cut Yeti does, and that layer of CS is snugged perfectly against your back/butt and around your shoulders, the more optimistic figures might apply, at least for some folks.