UKC

From all the writings I read everyone whose written a comment seem to think that goose down is warmer than duck down.

I dont doubt thats true but what I would like to know, is the difference a really 'marked' difference, 'significant' might be a better word. I mean is the warmth factor something we would notice if no one told us which down was used or is it just a sort 'barely' noticeable difference in the warmth factor? or is something anyone would know quite quick on a cold day?
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In reply to Removed UserAvaunt: A goose is roughly 4 times bigger than a duck, therefore its roughly 4x warmer.

In reply to Removed UserAvaunt: From http://www.featherind.com/faq.htm "Generally speaking, the best down comes from larger, more mature birds. When age and maturity are equal, goose down is better than duck down. However, down from an older duck is better than down from a younger goose. Larger Down has an extraordinarily high warmth-to-weight ratio. A duvet or sleeping bag filled with this down will be very light and incredibly warm. And it will last for decades.

On the other hand, poor quality White Goose Down will have smaller Down. It will not loft up, and has a rather low warmth-to-weight ratio. Even if there is more of this down by weight, it won't be as warm. Down from younger birds not only tends to have poor filling power, it will also tend to collapse in a relatively short time, because its fibers are too fragile. This is usually the difference between an inexpensive goose down product, and an expensive one."

In reply to Rock Badger: Badum-tish.

In reply to Removed UserAvaunt: All other things are unlikely to be equal though, so you're unlikely to really find out. Obviously by using more down you can make a jacket of cheaper down warm, but weight and bulk will increase.

In reply to Removed Useriksander:

Thats very informative iksander - but are the differences so pronounced that we would actually 'feel' 'quite' difference in warmth?

In reply to Removed UserAvaunt:

For a given weight it's a possible yes.

In reply to Removed UserAvaunt:

Down awesomeness:

http://gearandmountains.wordpress.com/2013/11/05/get-down-on-it/

In reply to Removed UserAvaunt: It is all about the fill power! Duck down with a fill power of 500 will be functionally identical to Goose down with a fill power of 500. The reason that you only seem to find the more expensive Goose down in the better jacket and bags is that Ducks just don't make high fill power down. Duck down is substantially cheaper, due to largely being a side product of a global food industry, so in a lower fill power down jacket - go for duck! Hope that helps a bit?

In reply to Removed UserAvaunt: As said its all about fill power,

500 is 500 (as long as its the same test, check EU or US tested, and to confuse further some companies state EU down which is US tested), and as long as it has the same fill weight its equal.

Also if you are not worried about weight, then a lower fill power of a higher fill weight will be cheaper and equally warm

you need to know fill power and fill weight of any down items you want to compare

HTH

In reply to Removed UserAvaunt:
A big difference, in my experience. I've got a goose down jacket. I's my fourth down jacket. It's thinner than the others, and yet the warmest.

In reply to Removed UserAvaunt: As others have said, it's PROBABLY all about the fill power. As far as I know there has not been a study that proves that FP 800 is significantly (in a statistical way) warmer than 700, 600, 500... In theory it makes perfect sense, and there's a lot of evidence from products, but it's something I am looking into experimentally soon. If anyone knows of any existing scientific studies that relate fill power to thermal resistance I would love to hear about it! It's worth noting that the differences between duck and goose down are not limited to their thermal resistance, but that's the thing most people are bothered about.

Where does eiderdown fit into all this? It's got a fill power of about 700 (it's a myth that it's any higher) but is - again - reputedly warmer than goose or duck down. Why's that then? OOh, big questions...

The other massive influence on warmth is fit and design, which so many people forget. We wear clothes not fabrics and I'd rather wear a well-fitting jacket filled with marshmallows than an eiderdown one sized for a hippo.

I recently wrote some stuff about down on my blog (link is above (thanks Charlie!)) but didn't cover quite a lot of the above as it's currently a bit of an unknown factor and so little research has been done on it.

This is a scientific study

http://www.medwelljournals.com/fulltext/?doi=javaa.2009.2650.2654
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In reply to Removed UserAvaunt: Yeah, but it doesn't go into the thermal side of things. There's plenty of papers discussing down's morphology out there.

In reply to Mr Fuller: agreed fit and design crucial, if it fits well it should be warmer,

also crucially with down, it has to loft correctly so correct amount of down in each correctly designed baffle

my thing with all these narrow baffle jkts at the moment is there isnt much down in the baffle and it cant loft properly, plus all the stitch lines make wind whistle through taking heat away.. i will stick with primaloft or similar at that temperature and save down for when its proper cold

In reply to gear boy:


It's obviously just a fashion thing mainly now http://instagram.com/p/fDpjiMrvB9/ but I thought originally it was about very light jackets with actually very little down in them, and the narrow baffles stop the down from sinking to the bottom of bigger compartments?


That's fair. It's actually noticeable in very cold conditions when you are wear a stitch through jacket in comparison to box wall.