Dec 24, 2011 at 8:02 am #1283313
Im sure this has been discussed somewhere – but i couldnt find something authoritative.
We all know in EU they have the EN13537 standard test with the manikin and all. Now im not saying that tests are exact or the final word about real world temp rating – but they do help compare apples to apples.
How does this sit with what US mfg do and no less importantly the cottage industry?
Am i missing something or are US based and especially cottage industry mfg somewhat liberal?
Just as an example:
Yeti passion 3 (http://www.yetiworld.com/en/produkte/schlafsaecke/passion/passion-five.html) Has 300g (10.6oz) of 900+FP down and is rated Limit +3C/37F (which is the lower comfort limit for a male. baffle is unstated.
WM summerlite – 32F/0C rating 10oz/280g 850FP down
Nunatak alpinist 20F/-6.7C 12oz/340g 850FP
Nunatak subalpinist 35F/1.7C 6oz/170g 850fp (0.75" baffle height…
these are all mummy bags (although the nunatak have maybe a more efficient hood
if we look at quilts (obviously these will have less fill since no hood…but still
Katabatic palisade 30F/-1C 9.5oz/270g 900FP
zpack (which has down all the way around) 30F/-1C 7.3oz/207g 900FPDec 24, 2011 at 8:08 am #1815553
A US manufacturer can claim any temp rating they like. I could sell you a bag with 1 ounce of down and say it can be used down to zero. :)
I find the EN ratings conservative, but i'm a warm sleeper.Dec 24, 2011 at 8:12 am #1815554
@mocs123Locale: Southeast Tennessee
You are correct, in the US, makers can claim just about whatever they want, which doesn't make things easy for the consumer.
I find WM to be spot on/slightly conservative. (I have owed a Summerlite and Ultralite)
I find Katabatic to be slightly conservative. (I owned a Palisade)
I have no experience with quilts/bags from Nunatak or ZPacks.Dec 24, 2011 at 8:12 am #1815555
@mike – i realize they CAN claim whatever they want – but how do we get our heads around it. Obviously with semi mainstream mfg like WM and FF there is enough experience to know they are pretty much on the money
but many of us use cottage gear – cause its lighter and ostensibly more efficient in design so it stands to reason that it could be lighter than a WM and still do the job
but how do we know? there is very little experience and anecdotal accounts (eg – i slept with my xxx down to 27F on the yyy trail one time and was toasty) is almost useless
MikeDec 24, 2011 at 8:18 am #1815558
You can look at fill weight and loft. There are some general guidelines that says X inches of loft will be good to about X degrees. I'd look for them but I'm on an iPhone while traveling this holiday season and don't feel like doing extensive sleuth work on a 3" screen.
Good luck!Dec 24, 2011 at 8:31 am #1815561
The gear manufacturers in the US have never been able to agree despite efforts by the OIA and REI to make it happen. They have all just agreed to disagree, and this has been going on for a very long time.
Pretty much what others have said:
Measure loft, preferably at the lowest point which is usually the knees.
Look at fill weight and fill power.
(BTW, WM uses the same high quality down as all of those using 900ci, they just like to be conservative so always claim 50ci less.)
Look at the cut, slim is warmer than wide unless too slim and then you compress the down and reduce warmth.Dec 24, 2011 at 8:38 am #1815565
I think it just comes down (pun intended) to experience. You use a few bags over the years, and you figure out what works for you.Dec 24, 2011 at 8:45 am #1815567
Good writeup about EN13537 including some comparison with U.S. "standards":Dec 24, 2011 at 10:09 am #1815581
Pretty sure WM bags have been EN tested, or so they told me on Facebook once. Good luck finding the data though. My Megalite has been spot on though.Dec 24, 2011 at 10:47 am #1815589
I know the loft tables (like the BPL one) and they are a fine guideline but not the whole story (over or understuffing, fill quality and geometry and shell material can make diff in real world)
Also know the Mammut PDF.
at the end of the day the thing we really want to know is thermal resistivity which is never measured in down equipment (except if they do a real test)
and if we do look at the tables it would seem that the EN13537 doesnt agree with say the BPL loft tables and that most cottage mfg use even LESS than that
why do we accept this? In the mammut doc they quote 1500 (i assume Euro) for a test – is it too much to ask a small cottage company that sells quilts or bags for 300~500USD a pop to test AT LEAST some of their designs (doesnt have to be all options at all sizes)
@mike Reid – I dont accept the "experience" line of thought:
Obviously experience helps as with any thing in life. and maybe if you are a hiker that logs 50~100 trail days in their native state then making a small mistake is nothing. If you are like me and buy your gear abroad over the web, and hike in the cold maybe once a year and it costs me ~2000USD to book the trip you bet your A@#$ss i want the gear to live up to specDec 24, 2011 at 11:15 am #1815591
as said the en-ratings are generally considered a bit conservative … i think i read somewhere that when mammut adopted their ratings their bag returns due to temp issues fell drastically, take that as you will
WM ratings can usually be found with some creative searching as european review and retail sites often list the en-rating
i personally wouldnt buy a non en-rated bag unless it was heavily discounted and even then id take the "rating" with a grain of salt
when you consider that THN, MH, marmot, REI, SD, Kelty etc … all en-rate their bags, theres no excuse for a more mainstream manufacturer not to …
as to cottage … you get what you order, they are smaller shops … thats the risk you take
its quite weird that BPL which is usually pretty scientific endorses use of loft rather than the generally accepted rating system used by many manufacturers both in the US and euroland …Dec 24, 2011 at 11:26 am #1815596
Martin RJ CarpenterMember
Actually that Mammut PDF discusses how much even the money needed for an EN test of a range really can add up. And for people doing lots of customisation and the like? Or of course quilts, but I don't think can be even tested at the moment.
Its not ideal though.
Suppose one other thing which gives you a plausible bit of comfort is when people rate roughly the same bags as the same. For instance PHD and WM seem to be pretty well aligned cf temperatures. Think its synthetic bags which can get seriously out.Dec 24, 2011 at 11:33 am #1815599
I wasn't being flippant when i said you need to actually use bags (experience) to see what works for you. Everyone is different. Just because a bag is EN rated to a certain temp, it doesn't follow that you will be warm in that bag. It's just an average, and some folk sleep warm, others cold.
Over the years, i've learned what works for me. Around 200/250g of down in a quilt will be fine for me down to freezing with clothing if needed. I started off with much heavier bags though, till i learned what i needed.
If i had only one cold weather trip a year, i would err on the side of caution.Dec 24, 2011 at 11:48 am #1815602
@awsorensenLocale: South of Forester Pass
Yes, but if lets say half the us manufactures did correctly rate there bags or quilts to what there claimed temp rate is, they would then have to add more down creating a heavier bag.
Then no one would buy there bags/ quilts because they would be to heavy. Those that don't meet the standard would double in sales due to having a 5 ounce lighter bag for the same temp rating.
Unless it's mandated, it has to be all or nothing.
What we need is a few type of temp rating and or loft in inches rating scale that manufactures can put "Complies to blah blah blah, loft, or temp standards". Hopefully the temp standards could just be the same as ENC.
Maybe in 20 years they can figure it out.Dec 24, 2011 at 12:36 pm #1815615
@rcaffinLocale: Wollemi & Kosciusko NPs, Europe
You have two factors here: ratings for the down and for the quilt/bag.
The Down ratings depends on which measurement standard you use. The inflated American one IDFL) relies on the down being absolutey bone dry and fluffed up; while the European one relies on the down being at reasonable ambient. By and large, a USA fill power rating of 900+ translates to a *maximum* of 800 for the rest of the world. Many times it will really mean 750. Why did IDFL do this? Because some down suppliers wanted to claim a higher value, so IDFL found a way to get that result. So the suppliers went to IDFL for the testing – more profit for IDFL.
The quilt/bag rating is even worse. The European EN13537 standard test has fairly tightly defined test conditions, and labs have to be certified. The test does cost money. There is an American ASTM standard (I think) but it seems to be very loose and many USA manufacturers don't bother doing any proper testing. I had one manufacturer tell me he didn't bother getting his bags tested (it cost $$!): he just compared his with someone elses. When that goes around a few times and each manufacturer errs on the generous side for his own gear, …
> are US based and especially cottage industry mfg somewhat liberal?
Some of them are totally cowboy! You cannot trust any claims which are not to EN13537 from a certified lab.
CheersDec 24, 2011 at 12:59 pm #1815619
@richard295Locale: San Francisco Bay Area
+1Dec 24, 2011 at 1:22 pm #1815625
Due to this, I love the fact that we can ask each other what works in what conditions. It's how I've chosen most of my gear. Better than any rating. Thank you to all for piping up with your thoughts and recommendations!Dec 24, 2011 at 2:18 pm #1815631
Unfortunately, what works in what conditions doesn't always work in what conditions!! :)
I could tell you that my 15* bag was good down to 10* on one night and I was chilly with the same setup when it was only 25* on another night!! (which is true).
But yeah, a lot can be learned by people's experiences.Dec 24, 2011 at 2:36 pm #1815633
As said in that Mammut document, you have to test every configuration/size for every model of sleeping bag, so especially for small manufacturer it's difficult.
But you could take a bunch of sleeping bags that are EN rated, determine temp rating VS loft for mummy/ractangular/quilt, and make a temperature rating standard that's easily calculated just based on loft. It wouldn't be as accurate as EN13537 but better than the U.S. status quo.
But, I think U.S. manufacturers don't care that much. Most people are into "fashion" like having pink dyed down you can see through the shell with matching pink trim.
If someone buys a sleeping bag and it's not warm enough, then they'll buy a second bag – twice as many sales.Dec 24, 2011 at 2:41 pm #1815635
The EN 13537 ratings involve the use of a sensor laden stationary manakin.
There is some question as to the validity of this approach since living humans move constantly ie. breathing.
The IDFL ratings involve testing the fill power of the insulation itself including durability testing simulating user washings and the effect of user body heat on the loft itself over time.
Seems like neither approach is quite as fool proof as would be ideal.
If i were a cottage manufacturer that sold a small quantity of gear in a given year i don't think i would spend the money to get either certification.
I think the "certification" by actual users via the internet would be adequate.
that is the most likely way to find cottage gear these days anyway.
My current selection of gear came about by either seeing it in use first hand on the trail by another hiker, or from anecdotal evidence on site like BPL.
Guess what? I have not been dissappointed yet.Dec 24, 2011 at 2:43 pm #1815636
"There is some question as to the validity of this approach since living humans move constantly ie. breathing."
Another factor is sweating.
They have tests that include that, but then it's even more expensive…Dec 24, 2011 at 3:01 pm #1815641
There are certainly issues with en-testing
– margin if error between labs
– how well the standard man/woman fits your type
– using a r5 pad
– rating bags below 0F
However the fact remains that it is simple the best MEASURED test available
It doesnt rely on how someone feels … As what is watm for one is freezing for another … And one could easily feel hot one night and cold another depending on conditions
As an example i refer to the recent posts on the summerlite … Some have used it fine below freezing, others were cold above freezing … Whats a person to do??? Btw the summerlite is a 34F lower limit male comfort bag
What en- ratings DO allow you to do is make comparisons between the relative "warmth" if bags … No amount of magical thinking or brand naming will make a 40F en rated bag warmer than a 20F ine regardless of the price
Looking at loft and amount of down is all good …. But anyone who took science in hs will tell you that direct measurements are best … Rather than depending on another variable which you assume has a correlation with what yr trying to measure …. Measuring insulation is not rocket science
En-ratings are a darrn sight better than the old marketing dept fantasy ratings that existed long ago ..Dec 24, 2011 at 3:30 pm #1815644
@jamesdmarcoLocale: Finger Lakes
Yeah, I agree with Roger.
But even the EN13537 ratings have some problems.
http://www.outdoorindustry.org/pdf/EN13537Mccullough062209.pdf is one document that describes some of them.
Sleeping on a pad is fine, But we ALL know there is a big divverence between a little 1/8" CCF pad and a 4" thick Down filled air mattress. It doesn't really say.
Clothing is assumed to be a single base layer, but it does not say it is a down filled VBL base layer or a fine super ultralight summer streatch base layer. Again a big difference. So, even the EN standards are not perfect, they only try.
Also, the ratings given to EN bags are typically done in three, sometimes 4 tests. These are compiled in a series to make a graph. This graph says a lot. It will usually state the comfort level, and some lower numbers(Lower limit, Extreme Lower limt, typically.) It also says, that I am comfortable at X temp, but at Y temp, I will need about this much more clothing. I could not do that without the EN rating, because, everyone sleeps differently.
Have a Merry!Dec 24, 2011 at 4:11 pm #1815649
@hikinggrannyLocale: Gateway to Columbia River Gorge
Thanks, Jerry, for the link to the Mammut article! It was very interesting.
While the EN13537 ratings aren't by any means perfect, they do provide more standardization than we've ever had, when many manufacturers (especially of the cheap mass-produced bags) pretty much made up their own. As pointed out in the article, even an accurately rated bag for a young, fit male is not going to work for an elderly female!
There are other factors, including such things as the draft collar in WM bags. IMHO, this feature makes the bag quite a bit warmer!
There is the problem, especially for the "cottage" manufacturers working on a very narrow margin, that those tests are expensive! I would very much like to see the standards adopted, but not if it's going to put folks like Nunatak, Katabatic and ZPacks out of business!
I would hope that if the EN13537 standard becomes universal in the US, and the volume of testing increases, that it will become cheaper (economies of scale as we called it in economics class).
I have read somewhere that the EN13537 test for 20*F/-7*C bags has the bag on a mat with R5 rating and has the dummy wearing a base layer and a warm cap. Does anyone have a reference handy? Otherwise I'll research this after the New Year.Dec 24, 2011 at 9:33 pm #1815684
EN lets you compare bag to bag "warmth", nothing else. The temp value is basically a general "range" that it should work but your own physiology (and even psychology) will affect what the actual temperature is. Well rested, hydrated, dry, and fed it will be a much "colder rated" then if you've just been climbing 12 hours in a wet snow storm and crawl into the bag like a drowned rat at 14,000 elevation ;). As stated above, bag design also effects how well the bag keeps in warmth as you move and breathe.
So again to ape everyone else, EN is great for comparing bag to bag but also experience will tell you what design you prefer and let you gauge a warmth rating based on quality and quantity of down (again synthetics get tricky).
It's half science and 2/3 art (I'm a math major, those numbers add up!).
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