Coat insulation terminology

[Jeff7]

It's time to shop for winter coats again. LL Bean has a nice "Comfort Range" thing for indicating the temperature range in which a coat will be most suitable. That coat there is quite nice, but it's also close to $200.

Other terminology I've seen though makes less sense. For example, this coat has "550-fill-power" goose down. Ok, great. Is it filled with the feathers of 550 geese? Is it suitible to -550K? (Which would be physics-defyingly-awesome.) What does that mean?

I saw another one that mentioned something about "120-denier" nylon. TFD.com defines "denier" as "a unit of measurement." Wikipedia wasn't too helpful either in this context.

I'm in Erie, PA. It gets fairly cold here, it's windy all the time, and I don't retain heat well.

Might anyone have any helpful hints as to what these "fill-power" and "denier" numbers actually mean?

 

[Howard]

Denier is the weight/mass of 9000 meters of thread. 120-denier is 120g per 9000m of one thread.

550-fill-power means that one ounce of insulation occupies 550 in^3 of volume. Density, you could say.

 

[Jeff7]

Originally posted by: Howard
Denier is the weight/mass of 9000 meters of thread. 120-denier is 120g per 9000m of one thread.

Let me guess, you used Google + Wikipedia.
How then does that translate to insulative properties? Will 120-denier insulate me against 50F temperatures, or would I be able to walk through a Bose-Einstein Condensate unscathed?

 

[Howard]

No, it's probably just the durability of the fabric when comparing the same material but different weights.

 

[fuzzybabybunny]

Fill power down: The number represents the cubic inches that 1 ounce of down will expand to in a vacuum. The higher the fill power, the higher quality the down, the more compressible it is, and the warmer it is for a particular weight (ex. 4oz of 800 fill power down will be warmer (and poofier) than 4oz of 600 fill power down). Very high quality down is 700+ fill power and maxes out at around 850. OK fill power is around 650. 550 to me is a bit low.

You'll see this rating all the time in down sleeping bags and down jackets.

 

[pyonir]

550 fill power will keep you warm if the outside temp is at the lowest 34.875F. Any lower and you will be chilled.

 

[fuzzybabybunny]

Originally posted by: Jeff7

Originally posted by: Howard
Denier is the weight/mass of 9000 meters of thread. 120-denier is 120g per 9000m of one thread.

Let me guess, you used Google + Wikipedia.
How then does that translate to insulative properties? Will 120-denier insulate me against 50F temperatures, or would I be able to walk through a Bose-Einstein Condensate unscathed?

It's more about weight and durability.

Higher denier fibers are thicker and coarsely woven, meaning they can take more damage before tearing and stuff. Unfortunately, this comes at an increased weight.

Lower denier fibers are finer and tightly woven. They can be very light and very very thin, but are not that great for stuff like bushwhacking. There are ultralight 800-fill-power 30-denier jackets on the market for backpacking, but 30-denier is just so thin it may make you nervous. Practically, it's not too bad unless you do something like take a spill and go grinding along the concrete, in which case you may end up being an exploding ball of down.

There's also wind resistance. A lower denier, closely woven fabric will act like a very good windbreaker, which helps substantially in keeping you warm and protected from windchill. There will also be some improvements in water resistance as well. High denier fabrics tend to soak through.

Also, a low denier, closely woven fabric will help prevent down from poking through and leaking out of the garment.

 

[fuzzybabybunny]

Originally posted by: pyonir
550 fill power will keep you warm if the outside temp is at the lowest 34.875F. Any lower and you will be chilled.

This really depends on the fill weight. If there's only 4oz worth of down in the jacket, it will be freezing. Something like 20oz will keep you nice and cozy, but it won't be as compressible or light.

 

[fuzzybabybunny]

Here:

http://marmot.com/fall_2007/me...ted/8000m_suit/details