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It is well known that a down sleeping bag should be stored as open as possible when not in use, but that can be squeezed and compressed to a very small fraction of its size when necessary (that feature is among down's best appeals).

I would love to know for sure if storing the sleeping bag in a compression bag down to its minimum volume (or, almost that) for several hours, like, 16 in a row, or 24 perhaps, will allow it to recover fully when the trip is over; or if over time even short bursts of tight compression like that are going to slowly ruin it.

I'd like to invest in such a piece of jewelry but I'd want to be sure that with proper care it would last for a lifetime or so.

Thank you so much.

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  • FYI Dakatine TL;DR stands for "Too long; Didn't read". It's kind of SE short hand. :)
    – user2766
    Commented Nov 13, 2014 at 9:45
  • @Liam My gosh, sorry. To me it looked like HTML tagging gone wrong.
    – Dakatine
    Commented Nov 13, 2014 at 10:27
  • Not a problem :) There's actually a wikipedia article on it en.wikipedia.org/wiki/Wikipedia:Too_long;_didn't_read
    – user2766
    Commented Nov 13, 2014 at 10:38
  • 1
    16 hours in a row is close to expected usage for many backpacking adventures. Commented Nov 19, 2014 at 5:25

3 Answers 3

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I emailed Feathered Friends and PHD about this issue. I only got a reply from FF so far:

A compression bag greatly reduces the size of a sleeping bag. There is no limitation to compressing down, as long as the down is not being stored compressed for an extended period of time, It will not be damaged.if you are taking it out and using it everyday. Just don't leave it compressed while not on a trip. As for the larger backpacks, some people believe compressing down can damage it. That is true for lower grades of down, but we only use the finest quality down so that does not apply to Feathered Friends products.

That is reassuring. EDIT: Also PHD got back. With this link, which I couldn't find before asking. And yeah its states that quality down not only does not degrades but actually benefits from occasional compression! From this link:

Some years ago, when testing the effects of repeated compression on down and various synthetic waddings, we found that after thousands of compression cycles the waddings had all lost between 30% and 40% of their loft, as expected. By contrast the down was 5% loftier than before - the compressions had merely warmed it up! This illustrates that down is not the fragile touch-me-not substance some people think. Treated right, it will give good service for a very long time.

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  • Being this an official answer from a manufacturer I mark this as the accepted one being it so far the most authoritative.
    – Dakatine
    Commented Nov 18, 2014 at 22:40
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    Just out of curiosity, how long is considered "an extended period of time"? What I'm really trying to get at is: if a new down or synthetic sleeping is packed up for a month, 2 months, 3 months, etc. how much would it degrade by? I'm sure there's some sleeping bag researcher/enthusiast out there who has tried to test this.
    – Cflux
    Commented Jul 11, 2022 at 1:00
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Over compressing any bag, whether it be down or synthetic, will eventually lead to loft degradation. If you compress your bag too tight you can cause damage to the barbs and barbules of the feathers, which will decrease loft over time, but this is apparently less of an issue with higher quality down. To be honest, I think you would have to have one incredibly hefty compression bag to actually compress a sleeping bag down to it's absolute minimum volume. Every compression bag I've ever owned seems to have a limit, usually where the buckles start to slip, or the seams start to burst. Never leave your sleeping bag compressed for longer than you need to.

Personally, I don't use a compression sack for my sleeping bag anymore. I use the roll top drybags with the webbing clips that came with my newer down sleeping bags and stuff those into the bottom of my backpack. They compress the sleeping bag more than enough for it to fit nicely in the bottom of my backpack, and they help keep it dry. Putting soft items in an overly-compressed compression sack turns them into hard items, which don't fill you bag very nicely. I've found that I can actually save space in my bag by allowing the soft sleeping bag to fill the bottom of my backpack and packing it down, opposed to putting a solid compression-sack in the bottom of my backpack and then trying to fill in all the voids around it.

I'm not the only one that prefers using drybags for my sleeping bag: The Experts View: Expedition Sleeping Bags

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    Thank you for your answer. Unfortunately, a winter alpine down bag (-20C comfort rating or even lower) would actually take more than half of a 60 liters backpack if packed that way...
    – Dakatine
    Commented Nov 12, 2014 at 22:59
  • @Dakatine - Mine doesn't. Down compresses significantly smaller than a synthetic fill, but compressing it too much will degrade the loft. What I'm trying to say in my answer is don't compress your bag as small as you can, just compress it enough so that it will fill the bottom of you bag. If you crunch your bag down until it's as hard as a rock then no, it will not last you a lifetime. These things will only last if you take proper care of them.
    – ShemSeger
    Commented Nov 12, 2014 at 23:33
  • I was indeed trying to realize what is proper care and what not. Being a climber I can't afford to use a massive backpack, it would bump everywhere during the climbs - plus, it would weight more being bigger. So. If you compress a bag like in this video, at minute 3:00, that bag isn't going to last as new for several trip, right? vimeo.com/23504388
    – Dakatine
    Commented Nov 13, 2014 at 0:34
  • 2
    @Dakatine - He's not putting his bag in a compression sack, it's just stuffed into the bottom of the bag. The way he's got his bag packed, after he gets everything in there that he needs, the sleeping bag would be able to expand and fill the left over volume in his bag. In an overly-compressed compression sack there is no room to expand, the sleeping bag can't "settle" into your backpack and utilize all available volume. Loft degradation is gradual, unless you leave you bag compressed for long periods of time (days on end) or compress a bag while it's wet.
    – ShemSeger
    Commented Nov 13, 2014 at 1:41
  • Correct. That was the wrong vid. Please look at this then. This is actually the kind of suff I'm into. youtube.com/watch?v=Uru-p3fGbaI Minute 4:35. Thanks :)
    – Dakatine
    Commented Nov 13, 2014 at 9:38
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I asked this question to my mother who knows well the quality of down. During your trek, if you compress your down sleeping bag a lot and if it's a very good quality down (90-10 or 95-5), you shouldn't have any problem in your trekking. It's very important when you return home to bring air to your sleeping until your next adventure, so hang it in your closet.

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  • That is actually what I expected and your mom'expertise in the field as a professional is very worthy. I felt like feathers would break - of course, forever! - as stated above, but that down would not.
    – Dakatine
    Commented Nov 16, 2014 at 18:51

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