Down FP vs Synthetic

[scum]

I understand that Down is superior to synthetic for warmth to weight. I get that 900fp is better than 800 because it takes less down to create more loft (equates to less weight for the same insulation). My question is at what FP does the down stop being worth it compares to synthetic insulation?

For example, (and I'm just throwing numbers out), if I can make an UQ that weighs 30oz to get me down to 0* out of 600FP down, but I make an UQ that weighs roughly the same out of some synthetic. Then why not just use the synthetic if its cheaper and less susceptible to moisture (ignore the packability factor I guess).

So at what FP does down's weight to warmth ratio stop outperforming synthetic? Is it ALWAYS better to use down over synthetic even if all you have is a real low FP or even something with high feather count?

[jasonb986]

Interesting question

[dragon360]

I have only ever seen 800, 850 and 900 FP used by vendors on this forum in there wares. 750 FP I did see with some DIY quilts and a little lower from some DIYer's that harvested from older gear. That being said, all my synthetic comparisons where made against the available 800 and 900 FP. Subsequently,even though I do have a synth set for really damp conditions (3 season), my primary setups are all down for weight and warmth considerations.

[pgibson]

Generalizing a bit...But around 600 FP would be my general cut off for overall perfomacne benefits of down. That would of course take into account that the down is indeed down and not feathers...as they provide very little more than filler. At about 600 to equally rated quilts will have near the same bulk, weight would probably be close to the same if not favor the synthetic (depending on what kind) and cost (with the exception of harvesting from pillows or another low grade source--(again pointing back to feather content) will probably be close enough to not be much of a benefit to either. When you go up the FP scale to 750-800 and beyond, cost will go up faster on the down side but pack-ability and overall weight will be improving as you need less down.

[nothermark]

Not disagreeing. As I recall 550 down was the standard for a long time back when. I think that is what Albany was comparing to when they developed Primaloft.

[I-NT]

Not disagreeing. As I recall 550 down was the standard for a long time back when. I think that is what Albany was comparing to when they developed Primaloft.

Question, What do the numbers mean eg 800fp 900fp ext when your taking about down???

[Catavarie]

Question, What do the numbers mean eg 800fp 900fp ext when your taking about down???

The FP (Fill Power) represent how many cubic inches one ounce of down will fill in a cylinder when compressed by a weight. Its determined by scientifc measurement so that the better quality the down, the better it will stand up to the weight. I believe they use a 1 ounce weight in the cylinder.

Basically the higher the fill power the less down you need to fill the item being stuffed, which means less weight in the pack.

[beep]

From Trailspace website...

Everything here comes from the IDFL website or emails exchange with down garments and sleeping bags manufacturers. I sent emails to manufacturers and some of them where very cooperative some not at all. But that's not the point here.

Fill power vs Fill volume :

Many people mistaken and believe that powerfill is defined as the volume occupied by 1 oz of down. It's not true. This is the loft or the fill volume.

So let's discuss the definition of fill power : it is the volume occupied by a down sample (usually 30 gr or 1 oz) subject to a certain pressure at a certain temperature (20 Celsius) and hygrometry (65%). This pressure is due to a mass that's put down the sample. The diameter of the mass equals the diameter of the cylinder where the sample sits. We'll call the compression cylinder.

Now what's the difference between US and EU powerfill :

US 2000 norm :

cylinder diameter : 241 mm
-conditionning : steaming+3 to 5 days in a sreen box
compression cylinder : non-mechanized cylonder of68,3 grams.
Mass of the sample : 1 oz=28,4 grams.
EN norm :

cynlinder diameter : 284mm,
conditionning : tumble dry +2-5 days in a screen box
compression cylinder : Lorch machine= mechanized cylinder weighing 94,25 grams,
Mass of the sample :30 grams
Now there is no exact conversion table between those two. But there exist some approximation. The usual one is that US FP=EU FP+50. Which is quite not true.

But there is an approximate conversion table for the cylinder used. Here we suppose that the methods of conditionning is tumble drying :

For down with a FP exceeding 700 cu in, there is an approximate difference of 4.3%. if it is between 600 and 700 cu in the difference is about 2.5 % and almost 0 for low quality down.

So a 800 EU FP down is about 840 US FP down.

Since 2005-2006 : the US norm started to use the steaming conditionning which (non artificially) improve the FP by about 50 cuin. So that's why 900 FP down suddenly appeared. Actually it's still a 850 US FP from before 2006 and manufacturer tried to trick us.

[scum]

From Trailspace website...

Yeah, read that the other day. No suprise that standards aren't quite standard and allows wiggle room for marketing magic. So, it seems that EU fill power is better than US fill power. Does that mean when it's marketed as European Down at 800fp, that it's EU standard or US?

Either way, I bit the bullet and bought an 800fp down pillow off ebay w/ 18oz of down in it for $40! Here's hoping it's at least true 800fp and not 760 US FP.

Thanks for all the info guys!

[BodhiKnight]

Yeah, read that the other day. No suprise that standards aren't quite standard and allows wiggle room for marketing magic. So, it seems that EU fill power is better than US fill power. Does that mean when it's marketed as European Down at 800fp, that it's EU standard or US?

Either way, I bit the bullet and bought an 800fp down pillow off ebay w/ 18oz of down in it for $40! Here's hoping it's at least true 800fp and not 760 US FP.

Thanks for all the info guys!

Down rocks in cold weather, but fill power is a lot of hype. My montbell jacket circa 2004 is full of feathers, its A joke.

Now its probably better down, Maybe.

I pulled some down from my montbell and compared it to the down I pulled out of a $150 target quilt and the target quilt is better. IMO