Sleeping Bag Questions

“So, I haven't kept abreast on what synthetic insulation choices have popped up on the market. Last I looked Polarguard 3D was the best choice for synthetic. What is being used in the lightweight sleeping bags? What are good synthetic choices?

Thanks for any info!”

“New tent and new bags? Lucky!!!!!!!!”

“Don't know much about it, but this bag looks sweet!

http://www.rei.com/online/store/ProductDisplay?storeId=8000&catalogId=40000008000&productId=47856917&parent_category_rn=40003493”

“This question is for a friend but it would always be nice to get a new bag.”

“WOAW! Another one of those backpacking-related threads! Could it be the red-moon rising?!?

I just went the "other" way after having all synthetic bags, finally bought my first down bag, 0 degree Big Assnes Storm King! LUV IT!!!!”

“1) down
2) Western
3) Mountaineering”

“Yeah, thanks on that one.”

“Can somebody explain what exactly the US Norm for sleeping bag temperatur rating specifys?

For example: a sleeping bag is rated 30°F to 80°F. Is 30°F the 'extrem survival' temperature or is it a 'comfort' temperature? Can I expect to sleep warm at 30°F if I wear normal, long underwear?”

“It probably represents the lowest figure the marketing chairman can post with out gagging. I don't think there is anykind of set standard.”

“Euro the Temp ratings are VERRRRY subjective. I have seen some 20F (using of course the accepted REAL standard based on whatever the king wanted and not the silly crap the rest of the world uses...(LOL)) bags that you freeze at around 30 ish (F). Then I have seen some 30F bags you will be sweating at 40F in.

So it depends on how you are dressed, what you have eaten, your own body chemistry, etc etc....I sleep cold, regardless, I will wake up at 4 am ish cold....the best I have found is if I drape the bag over me...and progressivly zip into it during the night....”

“lol @ ramblinrev
:-)

Sleeping bags sold in EU have to give temperature ratings according the European Norm EN13537, which gives three ratings:
Extrem Temperature: an average person should 'survive' 6hrs at this temperatur (more or less hypothermic, I guess)
Comfort Limit: an average man will sleep warm at this temperatur.
Comfort: an average woman will sleep warm at this temperatur.

I try to figure out if the european ratings are directly comparable with US ratings? For example if a rating in EU and US is at 20°F, are both talking about the same 20°F, or is one talking about extrem survival and the other about comfort? Is my european bag rather 'warm' or too 'cold' for US standards?”

“Euro from my experience European bags (lafuma etc) are pretty accurate. Heck I had a 35-45F bag that kept me okay down about 34ish.

The problem with the US system is that there is no standard....my advice is buy 4 or 5 REALLY good bags...the ones that don't work you give to your friends in the US so you don't have to worry about schleping them back across the pond.”

“....!?!

So, Europeans and Americans are not talking about the same when they say the same?!”

“According to Fred Williams, founder and past president of Moonstone, temperature ratings as they are currently used are pure bunk and should be abandoned.

"It is not all that uncommon to have users judge the minimum comfort limit of an identical sleeping bag up to 20 degrees apart. I know of at least one case where two users judged the same sleeping bag more than 30 degrees apart!" says Williams. "Even without the variables of environmental factors, clothing worn, food eaten, pads used, body size, fitness, etc., the perception of 'comfort' varies wildly."

"Testing instruments such as the copper mannequin provide clo data using a very controlled environment. The mannequin is a fixed size and does not roll. The comparative data that's collected is great for evaluating the comparative insulating power of bags used by the mannequin," adds Williams, "but how does it address the variables of body size (a small body in a large bag) or movement (nighttime rollers who constantly crush insulation), metabolism, and the other factors of the field?"

Gary Schaezlein, owner of Western Mountain Sports, manufacturers of Western Mountaineering down sleeping bags agrees with Williams wholeheartedly.

"We just try to be honest with what we are putting out and provide for our customer in the worst of scenarios, not the most optimistic," says Schaezlein. "In fact several years ago, we were copper mannequin tested and found our ratings were 20 degrees too warm--our 20 degree bag tested to 0 degrees for example. The bottom line with a bag is it must keep you warm."

Hallelujah to that! Moonstone also reports that they overfill their bags to ensure warmth. Wise field advise that I have heard dispensed over the years is that you can always unzip a bag if you are too warm, but you're going to have a problem trying to add more down or insulation if the bag's too cold. Of course, this doesn't mean you want to buy a bag that you will be sweltering in 90% of the time either.

One company, when asked how they were rating their bags, went so far as to state that they had their bags tested by the copper mannequin a number of years ago, and simply extrapolated the information into their current line.

Of course, those companies who choose to be more optimistic with their temperature ratings often come out ahead when you only catalogue-compare price, stuff size, temperature rating and weight. As any knowledgable retailer will tell you, as long as you know how to compare bags properly, temperature ratings are of little significance and merely serve as a starting point or a place of reference for the eventual purchase--hopefully an educated one.

The first word of caution from Williams is "don't get too caught up in the loft game because some insulations pack more insulating punch per unit thickness than others."

Indeed, tests conducted at Kansas State University indicated that a LiteLoft bag (no manufacturer listed) which had been abused until it had lost 27% of its original loft still managed to maintain 94% of its original insulating ability.

Because of all the confusion, a number of heavy hitters in the industry, including Cascade Designs, Sierra Designs, REI, Marmot and 3M insulations, banded together to attempt to hammer out an unbiased, meaningful, understandable and standardized rating system. However, since not everyone in the industry agreed that standardized temperature ratings are a good or even achievable idea, the plan went no where and the powers involved have decided simply to publish a unified position on what to look for in making a good sleeping bag purchasing decision...and it took how many years to arrive at this conclusion?

What, then, are the most important criteria to consider when buying a bag? Look at the foot section, hood area and draft tube. How are they designed? Are there any obvious cold spots? How do they compare with the other bag(s)? How much insulation is in the bag? Consider that bigger bags require more insulation to provide equal insulating qualities as smaller or more narrow cut bags. On down bags, do the compartments feel firm ( a good sign that prevents cold spots forming since down shift is minimized) or soft and fluid (a poor sign since the down is free to 'fluidly' move around the tube creating cold spots--only exception are those bags intended for the user to be able to shift down from top to bottom to adjust for temperature fluctuations).”

“Yes Euro, you are correct in thinking that. You should, and most likely.”

“when it comes to warmth the thing to really remember is that it's all about LOFT. look at the grade of the fill, the number of inches of loft, and the general construction.

as far as general construction goes the real difference lies in how the bag is quilted. sleeping bags that are box baffled will be much warmer than a sleeping bag that is sewn-through. this is a major, major differentiator in my book. like i said, it's all about loft. a "sewn-through" bag will have full loft in the center of a quilted band but where the bag is sewn through it will taper to 0 inches of insulation. that means there are "cold bands" in the bag and the hope is that these will average out with the warm bands. the net of this is that a sewn-through bag needs more loft to provide the same level of insulation as a sewn-through bag. of course a box-baffled bag is more expensive. they are more difficult to make than a sewn-through bag.

anyway, it's all about loft. that's the point i am trying to make. so if you are considering two bags from two vendors look at the quality of fill, the number of inches of loft, and the general construction. if both bags are sewn-through and have the same quality of fill then regardless of what the manufacturers rate them at they will have the same insulation properties.
last edited: 11/15/07 7:17:51 AM”

“oh, and the size of the sleeping bag is largely irrelevant in my book. i know the general idea is that a smaller volume is easier to keep warm -but- since i switched over to using quilts i actually sleep warmer than in my sleeping bag and it's not sealed up like a zip-lock baggie -and- i can move around, toss, and turn freely at night. so i don't buy the "more constrictive bags are warmer" theory whatsoever. perhaps this is true when you start to get into the sub-zero bags but then there are a lot of technical features that get added at this point (draft collars in particular).”

“LOL. Actually I have acquiered a sort of...mmmm...'sleeping bag anxiety'. When I close my bag - with hood, baffle neck and all - I suffer bouts of intense fear that my sleeping bags wants to constrict and kill me. Therefore the last couple of times I slept with my sleeping bag used like a blanket, and was fine, despite temps below freezing point.

I would be glad to hear from user sufferers of 'sleeping bag anxiety' and how to treat it.”

“For me I believe that some of the anxiety went away as I became more experienced with my gear and the outdoors. The only fear I have now is that I'm totally zipped up in my mummy bag and I suddenly need to jump up and run from a bear! (which has happened by the way, hence the anxiety) LOL”

“It took me several nights of sleeping in a mummy bag to get to where I didn't feel 'trapped' when I first woke up and want to claw my way out of it.

The worst is when you wake up and you've REALLY got to get out in a hurry (u know what i mean....) - made worse when its really cold and you've got the thing cinched down tight.

Practice and time will get you to a comfort level with the restrictiveness.”

“For those who need a roomy bag for turning and feeling free, look at Big Agnes bags. They have no insulation on the bottom, but have a sleeve that a pad slips into. That provides basically a floor, and you feel nice and loose because the sleeping bag doesn't wrap around you, and you can turn all you want. My wife has one and loves it. Plus, what insulation there is is above you where it can do some good, so they are warmer for the weight. In the Rockies and Sierra, down is the only way to go. For the PNW, that might be so true.

On ratings, Jimmy san and many others are correct. The only thing that matters is loft, and ratings are bunk. WM rates their bags very conservatively. I was on Rainier a while ago with two friends, and we threw our sleeping bags into our tent at a camp at 10,000'. They said I should be in the middle, because my bag was only rated to +15 degrees. Theirs were rated to -25 or something like that. However, laying side by side in the same tent, mine was 4 inches thicker than theirs. They froze their a** off, and I was toasty warm. Loft is the only meaningful measurement.
last edited: 11/15/07 8:20:54 AM”

“i'll second ib's comments. the wm ratings are pretty good for me, but again my wm bag is box baffled not sewn through (the reason i bought it) so i expected it would be a better deal. now i don't use it ever as i am now using a jacks 'r better no sniveller quilt. if you don't like the enclosed feeling of a mummy bag give a quilt a shot. i was a MAJOR skeptic until i tried it and after one night i was a total convert.”