Sleeping bag for winter hut stays

[DougPaul]

Does anyone have an opinion as to the length of the bag? I normally buy a 6' length bag. I realize many people put water bottles and other items in the foot area of the sleeping bag so maybe a "long" would be prudent when it comes to winter.

I don't need any extra length--I put the bottles etc near my knees.

Doug

 

[Chip]

I totally agree with the backyard experiment. It it so much easier to do trial runs...

Agree also. You don't want your first night out in a -15 bag to be -15. There are a lot of dubious ratings out there and it depends on how you sleep and what other gear/insulation you're using. Based on my experience with down bags rated +30 to -40, I wouldn't trust the rating on any bag with less than 750+ fill, and even then there are now "Comfort" and "Extreme" ratings. I was lucky to snag a new Valandre expedition bag, on a ebay store close-out a few years ago pretty cheap, that's 850+ fill. The bag's current equivalent has a "Comfort" rating of -4 and "Extreme" rating of -44, which I pretty much agree with, but that's a $700 or $800 bag, new.

 

[DougPaul]

Yet another of those oft-repeated topics...

Agree also. You don't want your first night out in a -15 bag to be -15. There are a lot of dubious ratings out there and it depends on how you sleep and what other gear/insulation you're using. Based on my experience with down bags rated +30 to -40,

Ratings can be rather inconsistent... Metabolisms are too so different people may require different amounts of insulation at the same temp. Fit, sealing, the pad underneath, wind, fatigue, moisture in clothing, and food are all factors too. There is a European standard for rating bags.

I wouldn't trust the rating on any bag with less than 750+ fill, and even then there are now "Comfort" and "Extreme" ratings.

Down fill is not a good measure of warmth. Loft is your best measure of warmth short of actually measuring the bag. 2lb of 400 cu-in/oz down should fill the same volume as 1 lb of 800 cu-in/oz down and thus, all else being equal, should provide the same loft and the same amount of insulation. (The 400 cu-in/oz down may be less affected by moisture...)

Comfort ratings are for comfortable sleep. Extreme ratings are for survival situations--you are unlikely to sleep, but you will probably survive.

REI has a nice little tutorial on choosing a sleeping bag: http://www.rei.com/expertadvice/articles/sleeping+bag+backpacking.html

There are some past threads with useful info (including how to estimate temp rating from the loft and desirable features for winter bags):
* Sleeping Bag Ratings: http://www.vftt.org/forums/showthread.php?t=6164
* Sleeping Bag Ratings: http://www.vftt.org/forums/showthread.php?t=14481
* Advice for a winter bag purchase: http://www.vftt.org/forums/showthread.php?t=33830
* Furthest below your bag's rating?: http://www.vftt.org/forums/showthread.php?t=8069
* Combining Two Sleeping Bags: http://www.vftt.org/forums/showthread.php?t=11079
* Combining sleeping bags for greater warmth: http://www.vftt.org/forums/showthread.php?t=16867

Doug

 

[kaseri]

Although I do appreciate manufacturer recommendations I'm very picky when it comes to gear. I suppose I'm narrow minded in that respect. For example I will only use a specific model crampon by a specific maker. The same goes for my ice axe, snowshoes, boots, shells, helmet, climbing harness and even my headlamp. I've been known to buy two or three of the same item just to have a spare in case the manufacturer stops production or changes the specs on an item.

In terms of sleeping bags I will only consider Western Mountaineering or Feathered Friends. I've used bags from both and they are top notch in every way. Since I feel comfortable with the quality of these bags I'm not willing to deviate. I know the Western Mountaineering bags are very warm and it seems to me the temp ratings of the Western Mountaineering bags are somewhat understated. In addition Western Mountaineering offers more options when it comes to shell materials.

 

[jfb]

In terms of sleeping bags I will only consider Western Mountaineering or Feathered Friends.

I have a FF Peregrine with Epic shell and it's great. One thing you never hear about is the final volumetric density of the down after it is stuffed in a bag's chambers. The bag's shell dimensions absolutely affect the potential loft of whatever down is stuffed inside. If a manufacturer puts the minimum amount of down that is needed to expand the shell to the desired loft, the bag will not be as warm as a bag that uses more down in the same shell.

 

[roadtripper]

I asked a related question a while back that may have some helpful info for you....

http://www.vftt.org/forums/showthread.php?t=34000

 

[DougPaul]

a bag that uses more down in the same shell.

That is often called overstuffing.

It may also make the bag last longer.

Doug

 

[BF]

Most importantly you want to have a comfortable sleep. If you do not get a good night sleep, on the following day you may have a lousy hike. Or, worst case, a poor sleep could ruin your hike the next day.

IMO a wider girth bag in a long size is only a few extra ounces of down. Considering all the items we carry in winter, that extra weight is worth it. I would not sacrifice sleep to save on weight.

With a wider girth bag you don’t have to sleep like a ‘mummy’. There’s room to bring your elbows up, bring your knee up or roll over. There’s room to keep some cloths warm (or dry) by your side. There’s room to place a warm bottle of water by your upper body without it digging in to your side.

With a long bag there’s room to put clothes and a warm bottle in the toe box. A long bag also allows room to pull some bag over or around your shoulders. (As mentioned in another post.) Something many of us like to do on a cold night.

A winter sleeping bag is a large expense. As suggested in previous posts, to rent or borrow a bag could be a good idea.

Keep in mind that to test a bag in your back yard is not the best test. Your body functions much differently when trying to bed down after a long hike, including being stressed out and partially dehydrated. If you do test a bag in your yard, leave the bag out there for a few hours before getting in. Brrrrr. That’s the way your bag will feel after a long hike.

 

[Chip]

If a manufacturer puts the minimum amount of down that is needed to expand the shell to the desired loft, the bag will not be as warm as a bag that uses more down in the same shell.

I wouldn't think that. The idea of down and loft is trapped, dead air. If you fill a bag to a 10" loft, it would seem to me that the minimum amount of down required to do that would trap the most air. Stuffing more down into that same 10" loft would just add feather weight and reduce trapped air...it would seem to me. Unless stuffing more in just increases the loft, but that's not what you're saying, right ?

 

[DougPaul]

I wouldn't think that. The idea of down and loft is trapped, dead air. If you fill a bag to a 10" loft, it would seem to me that the minimum amount of down required to do that would trap the most air. Stuffing more down into that same 10" loft would just add feather weight and reduce trapped air...it would seem to me. Unless stuffing more in just increases the loft, but that's not what you're saying, right ?

Overstuffing will at most only increase the loft by a tiny amount. However, as the down gets damp or worn, the extra down will maintain the full loft longer than the standard amount of fill.

Both the down itself and the trapped air provide insulation. Thus the loss of trapped air displaced by the down probably doesn't make a meaningful difference.

My first bag was overstuffed. It always looked like it was bursting at the seams. (Box construction.)

Doug

 

[jfb]

I wouldn't think that. The idea of down and loft is trapped, dead air. If you fill a bag to a 10" loft, it would seem to me that the minimum amount of down required to do that would trap the most air. Stuffing more down into that same 10" loft would just add feather weight and reduce trapped air...it would seem to me. Unless stuffing more in just increases the loft, but that's not what you're saying, right ?

Right, that's not what I'm saying. Measure the footprint of your down bag in square inches and multiply by loft. That's how many cubic inches of down it contains. Then, take the manufacturer's fill weight and multiply by the fill power. Compare the two numbers.