This is basically a question about EN vs. traditional sleeping bag temperature ratings and about the suitability of a particular choice.

I am trying to come up with the perfect winter sleeping bag. I sleep normal to cold. The two trips I have planned are Mt. Morrison (with a night in a snow cave) in February for which the equipment list calls for a -10 degF sleeping bag , and Island Peak in April with a 0 degF callout.

I'm looking at TNF Inferno 0 degF bag (an EN rated bag), but have some concerns: will it be warm enough, and does the center 1/2 zip allow for enough thermal regulation to use in tea houses. I do like the fit, however, the wider shoulders as compared with my Phantom Flame 15 are really nice. It is long for me - I am only 5'6.

I am also looking at Western Mountaineering bags, in particular the 0 degF and -10 degF down bags. They are rated with an in-house system. None of them zip all the way flat (the 5F bag does), but at least the side zip will work better than the 1/2 front zip for regulation in warmer climes. They also come in short and windstopper fabrics, which I like, especially for the snow cave. Shoulder width is there if I am willing to take a large footbox.

So how do I compare the WM temp ratings with the TNF ratings? And which bag would best suite my purposes?

Thx for your comments!
A

WM rating are going to be much more conservative (warmer) than TNF bags, hands down, I've owned bags by both companies. WM are far superior to anything TNF manufactures. Another manufacturer to look at is Feathered Friends, I also have owned FF bags and their quality and temperature ratings are on par with WM, which is to say far better than any big box brand.

For comparison, I have a +15 WM Apache Super DryLoft, 20 years old this year. I've taken it twice to the Alaska Range in early May and early June, and on too many winter ascents of Rainier to count. I've never been cold in it, although I sleep warm and know all the tricks to sleeping warm. I think certainly a 0 degree rated WM bag should do well for your trips.

I have a WM Kodiak MF that I bought in 2007 or 2008. I've used it in the Cascades in May and Mexico in Fall 2009 and at the deer lease. There really aren't many places that this bag can be used since it is so warm. EB is correct that the WM temperature ratings are much more conservative than TNF (I've owned both). I am most impressed with the breathability of this bag. In most sleeping bags I may get clammy and unzip to breath and then get cold. Not with my WM. As an aside, my wife loves using the Kodiak as a quilt for both of us with her Big Agnes spread out on the tent floor.

+1 for Feathered Friends. Their jackets and bags are exceptional. I simply got a deal too good to pass up on the Western Mountaineering.

ExcitableBoy wrote:WM rating are going to be much more conservative (warmer) than TNF bags, hands down, I've owned bags by both companies. WM are far superior to anything TNF manufactures. Another manufacturer to look at is Feathered Friends, I also have owned FF bags and their quality and temperature ratings are on par with WM, which is to say far better than any big box brand.

For comparison, I have a +15 WM Apache Super DryLoft, 20 years old this year. I've taken it twice to the Alaska Range in early May and early June, and on too many winter ascents of Rainier to count. I've never been cold in it, although I sleep warm and know all the tricks to sleeping warm. I think certainly a 0 degree rated WM bag should do well for your trips.

So you think that even though the outfitter is recommending a -10F bag I could get away with a 0 deg bag? I was looking at the FF Eider EX -10 Sleeping bag. It has deminsions I like and a price point that's acceptable. I do sleep on the colder side of average.

Thx again!

AustinKalb wrote:
So you think that even though the outfitter is recommending a -10F bag I could get away with a 0 deg bag? I was looking at the FF Eider EX -10 Sleeping bag. It has deminsions I like and a price point that's acceptable. I do sleep on the colder side of average.

Thx again!

I think a 0 degree bag from WM or FF will be as warm or warmer than a -10 degree bag from TNF, MH, or other big name brands. Whether or not you will be warm enough is hard to say, there are a lot of variables including how warm you sleep, what your ground insulation is like, what clothes you wear to bed, do you have enough calories in your body, etc. A FF Eider -10 is going to be a very warm bag. For comparison, I took a FF Widgeon -10 (similar to the Eider, but cut a little tighter), but with some overfill so more likely -15, to Denali and was warm enough down to -30 at the 17k camp.