Yar, a confussing topic to be sure.
Try this-
Attachment 96050
Keep in mind- I'm a ground dweller, but the info is basically the same. In my limited experience thus far, wind chill or "real feel" temp is a better number to use for UQ's. TQ's should work the same as on the ground.
There is more to this than CLO or loft- but this compares the two a bit more apples to apples.
Down is based upon loft- which has nothing to do with area (yards), only weight and fill power
Synthetics are based upon CLO- which is based upon ounces per square yard.
So this chart puts the two together based upon temps.
Loft does not equate to CLO! But loft and CLO can be compared by expected temps.
I included a warm sleeper and cold sleeper temp rating. Keep in mind- these temps assume you have on a base layer.
Finally- you can boil down the various fills to the ounces per yard needed.
Ounces of fill per sy yard is the only thing that matters, IMO.
WHY?
Because of construction.
Synthetic fills do not require baffles. Baffles add weight.
A typical full size quilt requires 5 yards of fabric to make the shells- regardless of fill- you need the shell- so still apples to apples.
A DOWN quilt requires baffle material, roughly 2 yards per quilt.
A SYNTHETIC requires no baffle material- no weight penalty.
Say you build an Argon .67 quilt.
In down- you need to add (.67x2 x1.05) 1.4 ounces of baffle material to the weight of the down. In synthetic you need zero.
So if you look at the green comparison- a 40/50 degree quilt needs 2.16 oz of down OR 2.5 oz of Apex. PER SQ YD.
The quilt takes 2.5 yards of fill-
Apex- 2.5yards*2.5oz= 6.25 oz
900 Fill- 2.5yards*2.16oz=5.4 oz + 1.4 ounces of baffles= 6.8 oz.
This number DOES NOT include "overstuff" which is typically at 25% for down. 25% overstuff would add 1.35 ounces.
This reason alone is why synthetic is "better" at about 35/45 degrees.
Something else critical, especially in low temp (30*F or higher) is to look at the baffle heights. 1.5" of baffle in 900 fill down means lots of cold spots, even with overstuff. To solve this you either have to do a sewn through quilt or decrease (add more material) the baffle distance. If you look at a typical down puffy you will notice that the chambers are more like little cylinders than rectangular baffles.
At temps above freezing- moisture is an issue as well- but that's a different discussion.
Point being-
You will see that at the green, orange, and yellow highlighted temps- you'll reach the point where down starts to beat synthetic for each fill.
The exception for you hangers that I can see- Down does a better job conforming to the geometry needed for an UQ. More accurately- you don't need a perfect fit in a down quilt to achieve the desired rating- so Down is more "hanger friendly" in an UQ in my opinion- although if you have to add in an UQ protector to your down because it's exposed- you should consider the weight of that as part of the UQ system weight- and again re-evaluate if the total system makes sense.
Same issue if you are adding heavier shell materials to protect your down. Synthetics not only work when wet, but require little or no protection (I.E.- a stray bush snagging you UQ will not cause a feather explosion, just require a stitch or two to patch)
My opinion- I would rather spend my ounces and grams on insulation, not material to make the insulation work or protect it from failure. So I would stay synthetic well into the 30's or 20's before considering down. Today's synthetics are much more packable than even 5-10 years ago.
This all also assumes cost is no object- material and construction costs are much higher in down- although I can see how some complex geometry UQ's could be relatively expensive to make compared to a TQ. But bottom line, material costs can easily double, construction time can quadruple with down.
Down does allow for infinite adjustment via fill weight. Synthetic comes in batts or sheets of a fixed size- so when Apex 2.5 isn't enough, you have to double it to 5 ounces per yard. Down can be micro adjusted to the gram.
What still isn't clear- how far you can push the Primaloft outside spec and still hit the expected ratings. Even with that unknown, Climashield Apex is still a winner in my book. There are other "flavors" but I personally am not a fan of the High Loft variety and trust the Apex 2.5.
There are many other pros and cons- to debate for sure- but on warmth per weight at least the math is there.
Bookmarks