Warmth of down jackets

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=18950

That post will probably be helpful.

In terms of warmth, the fill power rating doesn't mean much. A down jacket with 650 fill power down that is two inches thick will be just as warm as two inch thick jacket with 900 fill power down. Of course, the jacket with the higher fill power will be lighter.

Parka/jacket don't have any legal definitions, but I usually consider the difference to be that the parka is longer than the jacket, and most usually has a hood when a jacket doesn't.

A down sweater or a down inner jacket are intended to be inner layers beneath a top shell. In other words, the down sweater does not have a very tough shell of its own, and it is likely to get abraded or ripped in ordinary use unless it is protected by a top shell. You are likely to have a top shell anyway, and it is almost mandatory for rain and wind protection.

Your down garment has down baffles, and that makes it warmer than if it were sewn-through.

I was on Kili in June 2000, and I took a puffy down jacket in my duffle bag, and I fully expected to need it. However, it just never got that cold or windy, so I did not wear it. I was wearing several synthetic layers underneath my top shell. We had more wet weather than cold weather. Still, it could have turned cold on me and I would have had to grab the puffy down jacket. I would guess that you'll be OK if you augment that down garment with a thick synthetic layer or two.

For example, that thing has 900 fill power. That's nice, but it means that there really is not a lot of substance in the fill. It will be slightly fragile. If you keep it 100% dry, it will stay good. But if that thing starts accumulating any moisture (rain or sweat) then it is going to degrade. Synthetic layers above and/or below that would make it a bit more bulletproof.
–B.G.–

Gautman,

The Eddie Bauer Ascent 900 (EB900) has an Iclo only .22 higher than the EB800 and is 1.4 oz lighter. In laymen's terms it is classified as a down sweater. With a 1 clo base layer and protected from the wind, it will keep the average male thermo neutral at 29F at a 1.75 MET average camp chore metabolic rate. It contains only 3.88 oz of down. The sweater class typically ends at about 5 oz of fill.

A parka is a down sweater or down jacket with a hood and a length below your waist.

Many manufacturers offer both winter jackets and parkas with fill ranges up to 16 oz of down.

Expedition parkas typically range from 16 oz up to 60-70 oz of down fill.

If the EB900 rating doesn’t match your anticipated need, you can probably exchange it for another EB garment. Their EB Peak XV Down Jacket is a winter jacket parka class garment with a -18F rating. They also offer the Eddie Bauer Igniter Jacket which is a synthetic parka class garment with a similar temperature rating to the EB900 and EB800.

Richard, extremely helpful – thank you. Where do you find the clo ratings of the various down jackets?

I saw the article written by you a few months ago – do you do the measurements yourself or is there a calculation?

Thanks

Gautman,

I thermal test myself.