View Full Version : Sleeping Bag EN Rating System
ATX-Hiker
12-23-2008, 11:54
So I got my new bag for my early NOBO start a little while back and it had this handy little EN rating system tag on it, it's a Marmot Helium EQ 15* . There are three different temp ratings. Do these numbers really mean anything? Is the 15* rating based on some sort of average of the first 2 numbers?
1. Comfort 23.3* (Based on a standard woman having a comfortable nights sleep.)
2. Lower Limit 11.3* (Based on a standard man as the lowest temp. to have a comfortable nights sleep.)
3. Extreme -23.2* ? (A survival rating for a standard woman.)
So with this in mind should I be comfortable to 11.3*?
I'm also wondering if this will be warm enough for my Feb. 26th start. I have a fleece top and bottoms I planned on sleeping in.
Should I possibly look into a liner?
I was looking at the Sea to Summit Reactor liner as it looks and claims to be one of the warmest and lighter liners.
sleep outside when it gets really cold asap. IMO, only way to really figure out the temp rating of the bag, for u. Sleep temp is very individual thing. I think that bag should be fine with your layering stuff if needed. But you should try it out.
garlic08
12-23-2008, 16:58
Don't worry so much about those numbers. That is one excellent bag. I didn't even come close to needing extra clothing or a liner in mine, and I had several nights in the 10 to 15 F range. Good purchase, you'll love that bag. I switched to a 45 bag in late May and kept that for the rest of the hike.
The ratings are a point of reference. Have a look around you when you are at the shopping mall next time and you may notice that people wear anything from one to three layers of clothing at the same temperature, therefore no manufacturer can ever tell you if you will be warm in a particular bag. All you know is that if a bag EN rated at 23 is too cold for you , next time you need to get one that is rated to 15 or whatever. The point is that you should be able to switch from one brand to another with consistent results.
To put it another way a size 10 shoe is not necessarily big or small, it's just a size 10 ...
Franco
Liner is good to keep the nasty hiker funk off your expensive bag. You can throw it in the wash at each town stop. Cleaning a down bag on the other hand would be somewhat of a hassle on a thru hike.
Liner
Personal choice as usual, but I use one and after even just a couple of nights it can do with a wash. (however I don't usually wash it during my typical one to five nights out) Note that I always have a full wash and change into clean clothes at camp and don't particularly suffer from body odour...
The S2S Reactor has some bad reports due to its excessive "warmth gain" claims. A light silk liner is smaller , easy to wash , dries very quickly and they are usually cheaper. However some do like it , see
http://www.rei.com/product/705534#customerReview (http://www.rei.com/product/705534#customerReview)
Franco
Camping Dave
12-24-2008, 02:09
The ratings really don't mean much. IMHO, we'd all be better off if bag manufacturers advertised loft instead-of or in-addition-to temperature ratings. Test the bag.
By all means pack extra sleep wear if you are even the least bit unsure. Save the gram counting for the summer time.
Use a liner. I use a silk liner. Love it. Really does make the bag warmer by restricting air flow around your body.
Wear a hat during the night. Wear gloves. And, like I say to the Boy Scouts especially in cold weather, wear CDU's (clean dry underwear).
buckwheat
12-24-2008, 08:13
The S2S Reactor has some bad reports due to its excessive "warmth gain" claims. A light silk liner is smaller , easy to wash , dries very quickly and they are usually cheaper. However some do like it , see
http://www.rei.com/product/705534#customerReview (http://www.rei.com/product/705534#customerReview)
Franco
If you want a biv made out of Thermolite fabric, here's one that's 30% cheaper:
http://www.survival-gear.com/thermolite-emergency-bivvy-sack.htm
flemdawg1
12-24-2008, 11:05
If you want a biv made out of Thermolite fabric, here's one that's 30% cheaper:
http://www.survival-gear.com/thermolite-emergency-bivvy-sack.htm
Is it washable?
If you want a biv made out of Thermolite fabric, here's one that's 30% cheaper:
http://www.survival-gear.com/thermolite-emergency-bivvy-sack.htm
I don't think that one is made of Thermolite. It looks like it is made of a similarly named Thermo-Lite. They are both copyrighted so I don't think they are interchangeable.
So I got my new bag for my early NOBO start a little while back and it had this handy little EN rating system tag on it, it's a Marmot Helium EQ 15* . There are three different temp ratings. Do these numbers really mean anything? Is the 15* rating based on some sort of average of the first 2 numbers?
1. Comfort 23.3* (Based on a standard woman having a comfortable nights sleep.)
2. Lower Limit 11.3* (Based on a standard man as the lowest temp. to have a comfortable nights sleep.)
3. Extreme -23.2* ? (A survival rating for a standard woman.)
So with this in mind should I be comfortable to 11.3*?
I'm also wondering if this will be warm enough for my Feb. 26th start. I have a fleece top and bottoms I planned on sleeping in.
Should I possibly look into a liner?
I was looking at the Sea to Summit Reactor liner as it looks and claims to be one of the warmest and lighter liners.I think this sort of rating system, with descriptions, is a big improvement over a single number rating system. It is still somewhat vague because it isn't clear if it is based on completely naked individuals, or what minimal clothing they might have, especially for the extreme rating. Who doesn't at least use some sort of scarf when its that cold? In my opinion your clothing is more critical than your sleeping bag, but the two are closely connected, and with your shelter system also, as well as how fatigued you intend to be at the end of a cold day.
There seem to be at least 3 sources of variation amongst hikers.
1. Skin temperature tollerance while sleeping.
2. Initial skin temperature and duration of sleep.
3. Heat produced per square meter while sleeping.
I think this sort of rating system, with descriptions, is a big improvement over a single number rating system. It is still somewhat vague because it isn't clear if it is based on completely naked individuals, or what minimal clothing they might have, especially for the extreme rating. Who doesn't at least use some sort of scarf when its that cold?
The standard is actually pretty specific, and I think the testing has to be done by an approved tester, making it expensive to do. Also it's not required, it's a guideline. This creates the problem of two different standards, the more rigorous "tested to" EN13537 which get the EU seal, and the "complies with" that can still give their ratings, but don't have to be tested.
EU Standard EN 13537
Using a thermal mannequin placed inside a sleeping bag and dressed in a layer of thermal underwear and knee length socks, thermal dissipation is measured by sensors on the mannequin. Rating values are calculated based on information from these sensors and 4 values are determined:
T-COMFORT (COMFORT TEMPERATURE): THE LOWER TEMPERATURE LIMIT AT WHICH AN AVERAGE WOMAN CAN SLEEP COMFORTABLY.
T-lim (limit temperature): The lower temperature limit at which an average man can sleep comfortably.
T-ext (extreme temperature): Temperature at which hypothermia can occur for an average woman after approximately 6 hours.
T-max (maximum temperature): The upper temperature at which an average man can sleep without generating perspiration.
Thanks. That is very specific, and also quite instructive.
It would be interesting to see some research on how much things like skin temperature tollerance and heat production per square meter vary amongst people. The bag ratings are still about testing bags, not people. I would like to learn more about people.
Thanks. That is very specific, and also quite instructive.
It would be interesting to see some research on how much things like skin temperature tollerance and heat production per square meter vary amongst people. The bag ratings are still about testing bags, not people. I would like to learn more about people.
Yes, one bag company i read complained that because the dummy is a standard size, one could build a bag that fit that dummy best, and it would do better than a bag built for real people.
Over many years of hunting and tent camping in cold weather I have had the opportunity to test several sleeping bags and what I have found is that the comfort rating is very general. While one person may be comfortable in your bag at a given temperature, another may be very uncomfortable. For example, I am hot natured and one of the first people to start shedding clothes while I am hiking. But about 3:00 A.M. I tend to get very cold especially on the pressure points like the hips and shoulder. I started from Springer 3/1 this year with a 0 degree rated North Face synthetic bag. Inside of this during the day I kept a very thin set polyester long underwear and socks. Each night I put on the underwear and socks before gettng into my sleeping bag. I was very comfortable even when the temp dropped into the lower teens. As simple as it sounds, sleeping socks are important. Additionally this sleepwear keeps your bag clean and prevents you from having to use a liner unless you just want one. I threw it in the wash every few days with my other laundry.
In early April I sent the 0 bag home and my wife shipped my 25 degree Marmot to me. I got cold several nights in east TN and VA when the night time temps were in the "high" 20's.
My best advice is to take your tent, sleeping bag, etc. and do a 2 or 3 day winter shake down hike somewhere up north. I don't think Austin is the place to test it unless you get one of those blue northerns, also known as an Alberta clipper. Remember, you're going to be in the mountains and it gets really cold and wet in March and April in the Appalachians.
Sorry for running on so long. Just thought of something, A.T. thru-hiker named Steady-on is from Austin and she started in late February. You can contact her on www.trailjournals/steadyon (http://www.trailjournals/steadyon)
Good luck!!
The EN test is like telling you that you have 1/2/3 quarts of beer in front of you. Once you know that normally after 2 you have had enogh, next time you drink a beer with the same alcohol content you know to order 2 quarts.
No beer manufacturer can tell you when you have had enogh, no bag manufacturer can tell you when YOU will be warm.
If a Merino 200 top is too warm for you, then you use the 140. If it is too cold, use the 320. Bags are the same....
Franco
Skidsteer
12-24-2008, 19:31
The EN test is like telling you that you have 1/2/3 quarts of beer in front of you. Once you know that normally after 2 you have had enogh, next time you drink a beer with the same alcohol content you know to order 2 quarts.
No beer manufacturer can tell you when you have had enogh, no bag manufacturer can tell you when YOU will be warm.
If a Merino 200 top is too warm for you, then you use the 140. If it is too cold, use the 320. Bags are the same....
Franco
Now that's an interesting analogy.
Given that in the various forums every so often someone else will whinge about "inaccurate ratings" (even after the EN rating has been explained) here is another analogy that may work for city folk :
How come when you work in an office with more than two people as soon as winter comes someone will find the air conditioning too warm whilst others find it not warm enough and hardly anybody is ever happy ?
(so how do you expect a manufacturer to tell you if you are going to be warm...)
Franco
Weight, fitness, age, fit of bag, wind, fatigue, hydration level, and humidity, from my experience have all affected the way my sleeping bags have kept me warm (or not) in the past. It's obvious that being young, optimal weight, fit, non-fatigued hydrated, out of the wind, in a bag without extra girth and length, and in low humidity are key in being warm in the sleeping bag. So much to think about. Only actual experience will give you a true feel for your bag. Best to try it at home before venturing out into the wilds. Try it dehydrated, sweaty after exercise, and if you can stand it, after at least a 12 hour fast, in the open in the back yard on a windy night.
Try it dehydrated, sweaty after exercise, and if you can stand it, after at least a 12 hour fast, in the open in the back yard on a windy night.And a standardized rating system means you only have to do this miserable night once.