What is Your Sleeping Bag’s REAL Temp Rating?
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- Опубліковано 6 вер 2024
- Are Sleeping Bag Ratings a Lie? Sleeping Bag Temperature Ratings are an important part of finding the right sleeping bag. If your bag isn't warm enough it can be dangerous. But there are no laws requiring brands to adhere to any specific standard. Which makes me wonder. Are Gear Companies Lying To Us?
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EE Enigma 30: geni.us/Ecwme
Katabatic Palisade 30: geni.us/HPANyg
Featherstone Moondance 25: geni.us/Furlf
Therm-a-rest Ohm 20: geni.us/M71BvN
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The Quilts and Sleeping Bags Mentioned in this Video:
EE Enigma 30: geni.us/Zvulv
Katabatic Palisade 30: geni.us/CBJbCa
Featherstone Moondance 25: geni.us/5g8LFw
Therm-a-rest Ohm 20: geni.us/Ae7pU
TNF ONE BAG: geni.us/ZByS
So, what I'm picking up from this is that once you get into the camping/outdoors hobby and buy enough equipment to finally know what you're doing and keep at it, you've spent so much money on equipment that turned out to be duds that you have to try to monetize the gear that you wasted your money on, and making gear review videos is one of the more common ways to do that.
At least later generations of curious campers and research junkies are going to have an easier time of it thanks to your sacrifice. Your efforts are appreciated.
The loft measurement in inches is an inherently flawed concept (which should be obvious because if it was that simple then EN and ISO would use that method). Construction material matters as well. Trapped air alone doesn't create insulation, air movement within the material is critical as well. This is why closed cell foam would be a better insulator than an un-insulated air pad of the same thickness, and the same reason why a wall space filled with fiberglass has a higher R-value than an empty wall space (both have the same "loft" of 3.5"). So the type, quality, and density of the fill material is going to matter quite a lot, and that's without even getting into baffle construction, seams, draft, etc.
I was wondering how the loft system he was using would work with the advent of new materials. The points you brought up are also interesting in comparison models.
@@7raesloan Calculating heat loss through a composite medium isn't as simple as you might think. The algebra itself is pretty straightforward, but the devil is in the details.
I agree with this. It's a very broad, general assessment than is helpful if you only have time for a quick A/B visual comparison.
100% agree. Measuring loft is completely pointless. What keeps you warm is how well insulated you are, and that is not necessarily dependant on "loft". I'd even go so far as to say that loft isn't even the biggest contributor to insulation. If I had to guess, I'd say materials and construction are the biggest factors.
@@GDF07 Absolutely. Imagine how many inches of loft would be required for a temp rating of -200 degrees. Buzz and Neil wouldn't have been able to move. At the end of the day I think your best bet is to just go with the EN/ISO rating and if that's not warm enough then get a different brand/temp rating. EN/ISO have already done the work for you with far better testing procedures than the common person has access to.
Engineer here: A proper test would be to put a couple of gallons of water, in a container at 98.6F in the bag and measure how much time it takes to get to a lower temperature of your choosing. (say, 70F). The bags that take longer insulate better. Such a test will measure the actual heat flow and thus the insulative performance, not distance of a material ("loft") which might not be consistent.
Yup. Basically need to find the heat loss co-efficient for the sleeping bag (which is a function of loft, materials, baffles, seams, etc) which is pretty easy if you know the ambient temperature, the temperature inside the bag, and how much heat is lost over a set period of time.
Good idea but I think mass also plays a role; 4 gallons would lose heat slower than just 2 gallons. Remeber the heat formula: Q = mc∆T where m stands for mass
@@sircharlitos it’s pretty obvious that you would do such test in identical conditions for it to make sense
@@sircharlitos Well I suppose, if we REALLY wanted to do a good experiment we would need the same mass as a human since we are measuring heat Q flow and a larger mass will contain more heat even if it is at the same temperature. The heat flux rate through water is pretty close to a human. Then we would need to use the actual sleeping bag so it has the same inner surface area that the heat will flow through. Watt (used for heat, not electricity) per square inch.
If you really wanted to go nuts then we'd include ambient light, a wind speed, ground temperature, nuclear radiation sources...etc. This level of heat testing is what spacecraft go through.
Two problems with that test: The heat transference of vessels not made from fresh human skin are mostly going to be different from living human skin; and most people's body temperature is actually BELOW 98.6 F, a number that came from a study with a small sample population that were likely largely syphilitic, driving the average up; In addition, every decade the resting temperature of people born in that decade tends to drop by about 0.3 degrees on average, pushing it ever-lower.
Great video! Other considerations that are assumed in both testing Standards-
-Test occupant is (Fit) Male, (supposedly female anatomy sleeps colder)
- Occupant has some form of head cover; Hat, Beenie
- Occupant is well fed
- Occupant is not wet
- No wind
- Bag/Comforter is properly sized ( undersized bag insulative values will be compromised if baffles are being “squished”
Wow Mark. Excellent points. With the bags and quilt I've made, sizing has been important. To make the user comfortable I also consider how much space they want. Some people don't like the feeling of confinement in a true mummy bag. Me included. I think I will check out the standard methodology used.
- Occupant is a massive 190cm 140kg bodybuilder outputting a furnace worth of heat
@@Tyiriel haha
Generally speaking as you get larger your body surface to mass ratio goes down, so you lose less heat. So yeah, since men are generally both taller than women, and heavier than women of the same height as them, they tend to stay a lot warmer.
The local gear shop told me I only needed a 20 degree F bag for where I go camping. I bought a 0 degree F. Good call on my part. Down into the teens it is still nice and warm. Buy a good brand from a reputable source and add at least 10 degrees to the rating. I will say that if you actually live outdoors for an extended period you become acclimated and will in fact become comfortable at something closer to the posted ratings. I was in the Army for 4 years and we would be on field exercises for up to a month at a time where we slept outdoors 24/7, no tents, no heaters, etc. You find yourself able to wear less and less over time to remain comfortable. Good stuff costs money, you get what you pay for in some things. I'll pay to stay warm at night! Good video.
As a former aircrew member who went through survival school, and a former NICU RN, an acrylic liner is the thing that will keep your heat, period. It will keep you from dying, and is the primary and essential item for attempting to stay warm in any camping bedding.
Buying a surplus wool blanket, and sewing your own liner seems like the way to go for me. Real cheap, easy to do, and being wet is less of a concern.
@@nathanielkidd2840 thanks for the idea!
Or, probably, a silk liner, which should keep you warmer for the same weight, although I never tried it (but I am planning to buy one).
I returned a Big Agnes Sidewinder for this very reason. It was a '20 degree' bag and man. It was SO cold, even when using a 4.3 R Value pad. I got a 30 degree EN rated Nemo bag instead and it was just as warm as the '20 degree' BA bag. And now I have a 30 degree Katabatic quilt and it's even warmer than both of them!
Good points. The Sidewinder is a classic example of a good bag - the design is good, it's mostly DownTek treated down, with some synthetic fill, all good things. But it's really a 30 degree bag, not a 20. I've heard this quite a few times.
It is great you are spreading this information. I worked at a camping store and every customer came in saying they had been lied to before about what they needed out of their sleeping bags. Even the largest camping store in my country didn't adequately explain what customers needed to consider to pick the right bag. I never had any customer come back and say their bag was too hot or not warm enough when they were given the proper service. It just sucks that they needed the service and couldn't pick the right one off the rack because of the labeling
This is correct. A lot of the sleeping bags are not living up to the temps they acclaim This is not a big deal if it is summer camping. But for minus temps, this is critical. I have been doing outdoors for most of my life, and tried out a lot of equipment. Stay away from the cheap, that is just not worth the irritation. Still, there are north face, it is just bad, with all their products. They are just a fashion brand. ,
That loft measurement would only make sense if the filling was the exactly same type, there are huge differences in down quality and fibre quality, so this really is only an wild guesstimate, also the zipper and neckstrap are important areas of heattrapping
Found out 30 years ago take the temp rating of the bag and add 30 degrees to it and you are about right.
So the standard rating uses a R4.8 pad. Most hikers' pads are way less insulting. So my rule of thumb is to add 10F to the manufacture's rating. Regarding the loft formula. If the bag/quilt is sown through, the actual loft is not what is measured at the highest place. To get an accurate number, a more complex measurement is needed. For example. Measure every 1/2 inch across the baffle and calculate the average. Include at least one zero value. I think one would find a 2 inch max loft yields about 1 1/2 inch. Check out my sleeping bag builds on Tom Loves DIY.
Good point about sewn through vs box baffles. It’s hard to cover everything in one video.
@@MyLifeOutdoors yes it is. Good job getting to the issues. I have found that the only way to know how a bag works for me is to take it out on the trail. I have learned that a good base layer is important. And don't forget a warm hat, especially if you use a "headless" quilt. Thanks
My sleeping pad insults me every night!
My old North Face 32° bag I bought mid 1970s has the same loft as a 0° bag bought today.
2.5 inch for BA 15 degree
Only warm with full base layers and a thin liner at 30
See Ray Jardine claims that’s a 0F bag. Reading comments I’m beginning to believe loft has to increase exponentially the colder it gets.
Interesting article. I am looking for a new sleeping bag, and this article gives me food for thought. My takeaways from this article are: 1) the insulation needs to create enough loft for the environment you are in , trap air to minimize circulation and retain heat; 2) have an inner layer material (that’s next to your body) that allows enough heat transfer to the loft to keep you warm while not drawing too much heat away from your body; 3) have an outer layer that effectively inhibits heat transfer away from the bag (so essentially a barrier of some type); 4) combine your sleeping bag with the proper sleeping pad to avoid heat loss to the ground; 5) the formulas may or may not tell the full story, but may provide a starting point/guide when initially evaluating sleeping bags; 6) you might be able to use an additional/supplemental outer bag/cover/whatever to increase the efficiency of your bag/sleeping system; and 7) ask a lot of questions at the store, people using the bags, etc.. Understanding the different ratings, how they are used, and what they mean is very helpful. Another important thing to remember (for me) is not to be so focused on one brand or another, that you miss a really great product(s) from another (rival?) company. Thanks again for the information.
Buy a Western Mountaineering product that fits the temps you expect to encounter. They are great! I have 0F, 20F and 30F in their wider cuts as I am a side sleeper.
Sleeping bag loft measurements:
1) 1.875" Loft: "Marmot Phase 30", 42°F Comfort & 33°F Limit, ISO ratings
2) 2.125" Loft: "Marmot Phase 20", 33°F Comfort & 22°F Limit, ISO ratings
3) 3.5" Loft: "Western Mountaineering Antelope MF 5°", 14°F Comfort & 1.4° Limit, EN ratings
Great work as usual -- thank you!
Thanks for the info
I annoys me to no end the looks I get when I tell people I almost always have a surplus 66”x90” wool blanket when I’m sleeping outside. It’s not heavy, I’m only going a dozen or so miles, and in the winter months it keeps my back warm while fireside, without me having to worry about it getting a hole burned into it. It’s also big enough that I can use it for all sorts of things besides just a blanket.
My curiosity got sparked. I decided to test my down sleeping bag (Shavano) from Hyke and Byke which is rated at (and advertised as a) 32 degrees. I measured the top portion beginning at the top of the zipper to the piece of paper. The loft was only one inch: using both calculations learned here [100-(35 x inches of loft)] and [100-(40 x inches of loft)] the comfort rating came in at 65 deg and 60 deg. I was blown away because I didn't recall seeing this higher rating on Hyke's website. So I revisited their website and it turns out that the 65 deg rating matched their comfort rating, and the 32 deg rating is the survival temperature. All of their bags are rated this way. If I knew a few years ago what I took away from this video, I would have returned it. Granted it can be paired with a 20 deg or lower bag for layering in colder weather. Anyway, the information here is spot on and I will be using it, period. Great info!
Great confirmation. Thanks for the comment. I’ve looked into Hyke and Bike. I’m interested in reviewing some of their stuff. Maybe in a future video
Marketing a sleeping bag by not even it's limit rating, but it's SURVIVAL/EXTREME rating is absolutely criminal.
my old bag which i have owned for 30 years and it is rated at -5c and I took it to the Himalayas and across asia to eastern europe, from feb to may, and slept outside on a canvas camp stretcher with a silk inner bag i was never cold, even in snow.
As a general rule should get bag that is rated to 10°C below what a typical cold or very cold night is for your camping area.
Here's one I just found out about. I recently bought a women's Marmot Ouray bag (-18°c) rather than the men's Neversummer. Yes I'm a fella but I'm under 5' 10", and more importantly, I tend to sleep cold. The salesperson informed me that "often" , not always, a women's specific bag will have more fill to attain the same comfort rated temperature as the men's bag from the same manufacturer because the testers believe women sleep colder.
So if you're a cold sleeper like myself the women's bag is better bang for your buck.
I'm only passing on what was shared to me by the sales team. So please help me out if anyone has more info.
A useful video for generating skepticism, which should preexist when purchasing anything from a corporation. To anyone sleeping in dangerously cold climates, this video is a *healthy* reminder. You might have even saved a life here, sir.
my new Marmot Hydrogen's loft is about 6-7 cm. On the website and on stufsack the t-limit say -1 C but on the sleepingbag it say -3 C.
I did use it 3 nights now this easter temps went down to -2 and i stayed warm the entire night. I did use a Bivy and no tent
Very useful and needed presentation, Steve. Thanks. Something I think that would make it easier to test bags, and do away with comfort associated with individual persons, is to measure the R rating of the bag. Bring the bag to a known temperature, have a thermocouple in the middle of it, put the bag into a room of known different temperature, and see how long it takes for the inside of the bag to come to match the room temp. THEN people could add their personal situations. Really like the work you do, sir. Thanks.
The protocols do measure the R value of bags since they have a temperature controlled dummy in a temperature controlled room, the result is just reported differently.
Interesting! SO I did some measurements on my two nemo sleeping bags with same rating. here are my findings:
Nemo Forte with primaloft synthetic rated 20degree F : came at 6.5 cm to even 7cm.
Nemo Tempo synthetic (budget version, 50 bucks difference) came at 3.5 at the very best and feels less loftier and much skinnier. Granted, the tempo was used and forte is new, tempo been compressed couple of times, but no more then 48 hours at max.
It is interesting as I tried 0 to -2 Celsius here in Norway and with tempo in the morning I was feeling chill (night time was fine cause of bottle of hot water). You really make me go out now with my new sleep bag and test it, I am 100% sure it will be much better. Love the video and these type of technical videos is what make me happy!
I have found to put a fleece blanket under my sleeping bag. I have used my 20 degree bag in 10 degree weather this way. Yes this is a pain if your back packing. Great info for my next bag.
Interesting video! I never heard about this equation before, this will probably come in handy when looking for my next sleeping bag.
Also many thanks for adding metric measurements in the video, makes it much easier to follow for us euro guys.
I wished more US reviewers did.
Thanks for all the work you put into the video. I am a woman and have a 30-deg REI Magma quilt that has 2.5" of loft. Last year, I was in temps in the low to mid 30s and survived while using a 3.5 R-value pad with blue foam below it. I also had a rechargeable warmer pressed to my chest and a synthetic puffy under the quilt. Not a great night of sleep! This year, I upgraded to an EE 10-deg quilt which has 4" loft and bought a pad with 4.2 R-value so I'm hoping for a much better experience.
Thanks for watching. I’ve been surprised at how cold 3.5R can feel. But I’ve had 4.2 r in some fairly cold temps and been fine. I think you will be happy with the 10-deg/4.2 combo
@@MyLifeOutdoors i feel like the pad matters more, for me the bag in below freezing temps ill use is a twenty degree rated bag()usually synthetic) but using a folding foam pad with an r value of 2.0 and a basic self-inflating pad with a r value of 3.5 with their powers combined i get 5.5 and i appreciate that the lower rated bag can more moisture out faster than a thicker bag...
I have a Gortex covered Marmot bag, called a Gopher I think rated at 5 degrees, and needed it for the 32 years backpacking. Needed it once for a minus 20 degree night. Got it in about 1978 and have never had it washed (except for the nylon around the face) because other down items I had cleaned (by a professional down cleaning co) returned those with less loft and colder.
I've been in a tent with a guy and a bag with half the loft and no clothes where I needed a warm layer of underwear and we were both comfortable. Know your own body and experiment with the warmest first, the weight is worth the comfort. Sleeping with a hat and eating lots of fatty things at night to digest through the night and a good pad are also necessary. So many variables to keeping warm.
I even bought a Feather Friends to try to go lighter but still not as warm as my old Marmot. Don't remember the rating, I think they are a good company though.
.....cold female retired backpacker.
Thanks for your comment about adapting sleeping comfort when sleeping with another heat source. And the helpfulness of eating fats at bedtime.
Lots of bags will put the limit rating like you said. I've got a few like that. The worst offender is a "20°" mummy that is thinner than my 40° EE quilt. I've taken both of my EE quilts just below their ratings with no issues. I tend to trust cottage gear makers in this area more than big box store brands.
This is why I love my sea to summit bag liner in the winter. I have comfortably gone down to 0° while using their +25° liner and my 20° hammock gear quilt. Of course the sleeping pad really matters the most when keeping warm so you have to keep that in mind too. When I winter camp I bring my insulated klymit, a foam pad, and a reflective blanket to have in-between the pads and the ground. Idk if the last one really helps, but I feel like it does and that's what matters I guess
Hey Caleigh! I saw your last comment but couldn’t respond right away then forgot 😬. But it’s awesome to have you here! I’m so glad you fell in love with backpacking!
And you are so right on sleeping pads! I was thinking I should talk about it in this video but it was already feeling kind of long so I thought I’d save it for another video. I was on a trip a few weeks ago and my pad just wasn’t quite up to the temps. I bet a reflective emergency blanket might have helped. They are cheap and light.
I went to hammock for cold weather. I made my own underquilt using 850 fill goose down and has 2 3/4" of loft. I use Hammock Gear Premium Top quilt 10 deg.When I sleep on the ground, I've found below 30 degrees a 4.2 R-value inflatable with a Therm a Rest Foam Pad with my quilt sleeps warm. I agree loft is important but I also think the insulating material and if a person sleeps hot or cold has to be considered. Sleep warm my friends and Happy Trials.
I got a North Face bag for “summer” (I’m in Alaska) and it’s a 20 degree bag.
Slept at 6500 feet in Death Valley a few weeks ago as all the snow was hitting SoCal. I guess I can say now but I’m lucky I was sleeping inside a car because the EN limit on the bag is 22F.
It got down to 14F that night. I was layered up and had an R 4.9 pad, but boy howdy, I learned that the ratings north face uses are uh….not comfort oriented apparently.
Every person needs a different amount of insulation, which is why there is a range from the comfort to transition rating! Females tend to need more insulation and also many men who “sleep cold”. The need to stay at or above the comfort rating. Many men tend to “sleep hot” and can therefore sleep in a temperature much closer or at the transition rating. I have slept at the transition rating on my 20F sleeping bag several times and been warm, but I know my fiancé would have been FROZEN in that same circumstance
Alpkit Pipedream 400 down bag. 2" loft, rated -4C comfort. Chilly at -2C, even with merino thermals and puffy jacket.
Sleep pad rated 4.
As for my Big Agnes bag, yes I have tried it and it is factual. 30 degree bag was great until temps reached low 20s then it was miserable.
My Aliexpress IceFlame quilt (only $120 and 22 oz btw) has about 2.5 inches of loft and is rated at 41F comfort. It's easily warmer than that. It's easily comfortable down to 32F, maybe beyond that.
What’s the model of that please mate. I’m in UK and I’m looking to give a quilt a go this summer but I’m reluctant to dive straight in spending big bucks.
Good looks i might have to snag one of these been needing a 30-40 range quilt but didnt really wanna spend a bunch of money.
Wich one is it you have? Cuz they have a model that is called standard 32f 😁
@@Felixbrannstrom That's what I have I believe. I think they've updated the specs. It's 700 FP and has about 12.7 oz of fill.
This is a great video. Just came home from camping in cold weather, temp dropped to 37 degree at 640 am. We had REI trailmade 20 degree mummy sleeping bags. The ISO T-Limit is 18, T-Comfort is 29 on the bag case for ratings. LOFT measured was 2 cm, hence temp rating should be 30 degrees per this video, using the video's corrected 100-35xLOFT formula. I slept w/ only thin pajamas on, and no way could handle at 37 degree. Not even close, was freezing. We then used a Mr Heater Portable Buddy to heat the tent to about 50 degrees all night and the sleeping bag was just ok for warmth. I would say that our sleeping bag true T-Comfort is closer to 45 degrees. Unless you are supposed to wearing sweats or thermal underwear as a base layer with other clothes on top, the bags were not retaining our heat well.
The other thing to bear in mind is the size of person in the bag - e.g. I can be just fine in my bag but if you put my 5ft 2 daughter in it, she is freezing unless fully clothed with a coat on. Mine is a Vango UltralitePro 300 (2017) with a fleece liner - it's all synthetic fibre. Rating is -1C Comfort rating, -4C Limit rating and a -24C Extreme rating. 3-4 season. with a heat reflective and water resistant layer. The loft is 2.5 inches across the body and 2 3/4 inches around the shoulders and neck. I am not sure the loft is fully linked to the rating as the filling is as I said, main made fibre, we have that heat reflective later and also a man made fleece lining as well. To be honest I tend to sleep in my base and mid layers at anything below 8C in any case and with my outer layer, and hat at or below freezing - being bald mans that noggin tends to lose more heat anyway!
My conclusion is if you get cold easily, get the puffiest sleeping bag and try it out in your backyard at all the temperatures you’ll need it. Bag liners and base layers can be used if you’d use them. If you tend to be hot all the time, go with the manufacturer ratings. And I think rule of thumb, the less mass a person has, the warmer the bag needed.
Given that, I think what is needed is a dummy that is heated to 98F and can maintain that heat at 70F. Then put that dummy in sleeping bags in various temperatures and see how long it takes to drop temperature several degrees-this I think would give a better idea of how insulating the bag actually is and would simulate a human experience better.
It would be nice if companies could just be honest
They are being honest, but with different rating systems. Degrees COMFORT or degrees SURVIVAL.
@@Bohonk212 Exactly. People just need to be knowledgeable and thorough in their research and purchasing, and have some experience to where and how it all relates.
Is that for synthetic or down.
Is that for 750 fill power or 900 fill power
I think it's hard to tell unless you have different formulas for different fills.
Just my opinion... And that's worth about as much as a temperature rating.👍
Fill power only effects weight. 900 and 750 fill can both produce the same loft/warmth. But it takes less 900fb feathers to produce the same loft. Fill power is a measurement of how “fluffy” the feathers are. So it takes more 750 feathers to make a 2 inch loft than 900.
This is something that should have been said (that and r value of sleeping pads) but It’s hard to get all this information into one video without it being REALLY long. I even felt like this one was getting a tad long. Thanks for watching
Katabatic 30F quilt sleeps much colder than a Western Mountaineering 30F sleeping bad. The quilt is much more comfortable for me as I am a side sleeper and restless. I am going to buy another quilt that is rated at 20F and use when temps are expected to be around freezing. Anything colder and I will go with my WM 20F bag. The Katabatic 30F is just 2” tall. I should have ordered extra fill or gone with a 20F.
It’s worth noting the two of the best bag makers, Western Mountaineering and Feathered Friends offer models that are narrow mummy bags or a wider version. Trade offs there concerning cold spots vs comfort to move. And then their is fill count to consider. I go 800 or above on any product. Thanks for a good video!
this is why I always add 10 degrees to what the comfort rating is and couple a sleeping bag with an urpro waterproof fleece lined blanket. Sandwich myself in the middle and always keep toasty warm.
Glad you covered this subject. I have never bought a sleeping bag that has ever met my expectations. All the best and always remember to follow your nose!
74 yo male. 5’10” 160 lbs.
Feathered Friends Hummingbird Ultra lite. 20f. 950 GD fill
Purchased new early 2014. Used ~350 nights. Washed 1x by FF after 300 nights. Stored loose.
2023: Upper 30’s inside Duplex tent. Tyvek groundsheet, no bag liner used, 1/8” ccf mat under Thermarest xlite torso inflatable pad. Worn: Patagonia Captherm top, Mtn Hwr Ghost Whisp puffy, beanie, shorts, PearlZ leggings, sleep socks, down mitts. Cool by 3a. Added OR Helium 2 rain jacket. 2:05
I've great respect for Ray Jardine and his formula is probably right given a certain set of preconditions. I also believe that the height of the loft is super important, but the "amount" of insulation per inch (or cm) isn't the same for all types of insulation. Also, sewn through or baffles, type of baffles and type of fabric used will also influence to some degree so using one formula regardless of construction and type of fill just wont give reliable results.
It's an important point you make though that you shouldn't take manufacturer's claims as accurate. Still, I've used many bags from different brands and (as a warm sleeper) I've never felt that the rating was super inaccurate.
IMO the ratings from the manufacturers are just part of the problem. Even more difficult is "calibrating" yourself compared to the "average" person used to determine the ratings.
thanks for also showing metric and celcius. very helpful
TEMP. RATING (f) EQUALS 75f MINUS 20 X (LOFT MINUS 0.2 INCHES) The 20 is a constant based on Marcia Ratliff sleeping loft rating chart. The 0.2 inch correction compensates for medium weight wool sleeping clothing from head to foot.
Interesting equation. But how does it work? I have a NF Inferno -40 expedition bag with 10” loft (12” foot box area) and if I do the math out… 75 - 20(10-.20) = 75-196 = -121. I know that bag is warm as hell, but there’s no way it’s that warm. Even if the loft was 7” it’s still 75-136 = -61.
Or am I missing something? Thanks!
Since the above post by you I have done some Goofle searching and found some more date. I have modified a graph that shows !) Jardine's model, Western Mountainering model and data, AND the model I made from Enlightened Equipment data. @@MCFCTheMadHatter
I wish ISO would measure with a 4.0 R-Value pad. Seems much more obtainable for the average backpacker
I would be interested to see how they measure a quilt with the mannequin because you lose a lot of warmth from the head (at least I do) and quilts don't have the option to cover your head to save some grams
I have this Nepalese woolen beany that is so thick it stands up on its own. I wore it on a Minus 10 day with a wind chill factor that made it much colder. My head was too warm and sweaty while the rest of me struggled to keep warm in 3 layers and a German army Greatcoat over my Jacket. A quilt you can bunch around your neck and ears and add a beany for the top. I feel this works better than a hooded bag.
What I do is simply take what manufacturer think bag is rated for and if that number is 0 or less, I subtract 40. If its greater than 0, I just assume great for summer but not if it gets cold. For really good, really cold weather, look up wiggys. (I posted the link on the wrong video, as its better here, but don't want to repost it.) They are the only ones who Canadians who live in very cold areas, claim to really work for -40F and colder. Still, I'd use 2 sleeping pads if I could. But to really stay warm in arctic cold, I found that the weight of a very good made faux fur coat, can't be beat! Problem is, I can't buy that fabric. I tested a Burlington coat factory's Faux fur borwn coat in -75F windchill with a rabbit fur hat with ear flaps (authentic fur) and I was roasting!
I had a Rab Neutrino Pro sleeping bag in Scotland in March, rated to -5 comfort. Glencoe was -2 and I was butt naked in the bag, possibly to warm! Tent was an MSR Elixir 2. Great stuff! Keep up the good work!
Elixir is a hot tent! You need a 10-degree night with a good breeze to be comfortable in it lol.
i think that makes a good point. your shelter does matter.
whatever you get, test it in the backyard to really figure out how well it works for you, then go from there
I have a Lightwave Firelight 450 and the Temperature ratings are correct. I sleep rather cold but have taken the bag down to -6C and was just about OK (lower Limit is -5, had a pad with R 4.2) ... but I had other bags that were just wild in their ratings.
yah, something the Jardine's formula overlooks is quilt vs mummy vs rectangular. A tightened up mummy bag requires less down/loft to accomplish the same temps as a quilt or even a rectangular because of a lack of open/wasted space . ALSO the human in the bag matters. I personally tend to emit a bit more heat then some folks, but not as much as others, but that said most 30 degree (comfort) rated bags I can take down to close to 20 before I start to chill..I I have had my Western Mountaineering Terralite down to 15 degrees before it gets uncomfortable (tested on my back deck during winter, it's good to know your limits in your gear). Speaking of, that is a 25 degree rated semi-rectangular, I measured it at about 2 and 1/4 inches of loft. I like that bag though because it has a zippered footwell that essentially turns it into an overquilt. So it really is a 3.5 season bag for my uses. Good video!
Good video, thanks.
(edited)
Here is a budget sleeping bag measurements:
Mountain Warehouse Summit 250
~1-5/8" loft, rated (by manufacture) as comfort -1~4 degrees Celsius, extreme (survivor) -17 degrees Celsius (I hardly doubt it)
* edit the measurement because I got it wrong
In my limited experience, the bag is warm to 4 degrees and acceptable to -1 degree if well paired with a good pad. I was caught in a -1C overnight with it and the very wrong pad (a 2 season pad). I could sleep mostly well although feeling some cold from the ground on my back. On top I was not cold (comfortable yet) but the back was not good - hence I kept turning on night long. This makes me think that if I had the right pad for the occasion, the sleep bag would had been enough. Very good for a heavy synthetic budget sleeping bag. But again, limited experience speaking.
I always add 10 degrees to their rating.
Sleeping bags can be trusted to be over rated. Often by about 20 degrees F.
Courtesy of Half Vast Flying
I always go with the comfort rating as the lowest, I ignore the others. If it’s a 0c comfort bag I won’t use it if it’s gonna be more than a couple degrees lower or I know I’ll be cold
separate tanks for metric units! Great value and straight to the point
An interesting formula so I checked it against my 2 main bags. Both are box quilted down and well made with all the features like neck and zip baffles to maximize performance and they fit me. I have used both bags enough to have a good idea of their real world performance. On the formula (using 35xL) the light bag with 2.25" loft comes out at 22f or -5c which is about spot on for comfort rating in a tent with an R 3+ pad. So Check
My heavy bag has 4.5" loft using the same formula this would give a rating of -57f or -50c which is way off. its comfort rating is around -20 or -25c -8 to -13f with an R5+ pad.
Conclusion is that this sort of formula works quite well for 3 season backpacking ranges in the temperate zones but not for seriously cold weather. This chimes with my experience that the level of insulation needed is NOT linear, -20c is more than twice as cold as -10c.
The only two brands I would completely “trust” when it comes to ratings are Western Mountaineering and Feathered Friends. In fact my impression is their ratings are on the conservative side because they are protecting their brand’s reputation. Interesting you are primarily measuring loft. People use to other brands and quilts are generally surprised by the degree of loft when they get a FF or WM bag. These brands also understand the importance of loft that’s why they come with separate cotton storage bags that don’t unduly compress the bags.
agreed. Western Mountaineering bags are probably some of the best in the world (and some of the most expensive)
My almost 15 years old Marmot Pinacle rated -9C feels a lot warmer than bags from other brands that are rated twice as low, they come in the cotton bag for storage. My gf got a Marmot as well and it too feels conservative, I would trust them based on our experience. I'm happy to learn of other good brands
@@roguenoob my marmot 2 season mavericks rated to 40F (4C) is def not warm enough for 40. Only 50 (10C) in a base layer. It is older and might benefit from a wash tho. ;-). Mostly pointing out even within a brand, there's variation.
This is fun. I have a Deuter Astro pro 600 (new model) sleeping bag, which rated to -5 Celsius comfort temperature.
And, bag's loft is 7 cm.
They do claim that bag has a limit temperature of - 11 Celsius, at which "‘an average adult male can expect to sleep comfortably in a relaxed position".
Don't think this is true, at least for me.
One night at around -5 on the snow was fine, and I slept in a t-shirt and boxers.
But later, on the next camp, I had rainy weather and humidity was high.
On the second night I pulled my fleece top and bottom, however, the temperature was around +5 Celsius.
It's a down insulation, yes, but the bag itself was dry with no exposure to the water.
cheers
I used my TNF one bag in -8 to -22 C night, and I was ok. not toasty, but slept fairly well. It's not as comfortable as my Patagonia -7C, but I was happy with that.
Loft would only work if all bags used the same materials. A wool blanket is warmer than a cotton, (their loft being the same). One would need a different scale for each insulation type.
It may be more accurate to compare the weights of bags with the same insulation. A 2 lb 600 fill down bag should be warmer than a 1 lb. a 4lb poly bag should be warmer than a 2lb.
If you see bags rated for 32f, and and then see another of the same material and weight rated for 20f, that should be a clue that someone is using more generous terms.
More loft doesn’t always equate to more warmth imho. I have old 20 degree 550-fill bags that feel or seem warmer than 850-fill bags. The higher fill power down seems too light, lofty and spaced out by volume compared to hezvier clusters of 550.
My experience is opposite. I got a 20 degree bag expecting that it would be comfort rated to 10-15 degrees higher. The actual EN comfort rating is 21.6 degrees and the limit is 9 degrees. This makes my bag quite a bit warmer than I was expecting and I do overheat most nights I sleep in it.
Biggest reason people complain about their bag not being warm enough comes from 2 issues, not the rating. The 2 issues are 1) their sleeping pad R rating and how much it is inflated and 2) while you are sleeping is your body pressed against your bag reducing the down loft? For example I have a Big Agnes 15 degree mummy bag. When I sleep on my side my upper shoulder reduces the down loft to less than half an inch creating a cold spot; same for my feet. If I sleep entirely on my back like a mummy I remain warm but can’t sleep. I can even wear wool socks and thermals and still will be cold wherever my body is compressing against the down. I have since gone to a UGQ 20 degree wide quilt which allows me to sleep on my side and I stay toasty warm. No wool socks or thermals even when it’s in the 20’s. One last thing I also use a silk cocoon to keep quilt clean from body oils and stench. It too adds some warmth and helps to reduce the chance of your body compressing up against the down loft.
R value is certainly important. But it’s hard to cover everything without the video getting too long. But thanks for pointing this out
@@MyLifeOutdoors your video was quite informative I was just adding personal experience…
Are gear companies lying to us???? A: Do bears do it in the woods? Both answers are the same! I bought 2 sleeping bags rated for 15-20 degrees thinking awesome! we're staying warm NOPE!
in the middle of the night, my wife was crying she was so cold. It was COLD. I was able to return the sleeping bags. I learned a lesson that MLO is addressing in this video. Great video!
I just measured my bag, because it is hotter than expected.
Cumulus Teneqa 850, comfort rating -15°C (5°F), limit rating -23°C (-9°F), extreme rating -46°C (-50°F)
I found that it has about 19cm (7,5inches) of loft. Which explains why it is so warm in demanding conditions. Compared to a friend's bag with a comfort and limit rating quite close this was toasty!
(I have some other Cumulus stuff. All their ratings seem to be conservative)
Although that formula breaks down really badly on these colder ratings! (-200 ???)
10 degree EE quilt. Measures 3.5in. I also believe that EE says they over stuff all of there quilts. So that may be where it is off on the calculation vs the claimed temp.
Great video! I have to think that Ol’Ray was thinking limit or survival rating, given how his numbers always seemed to work out lower than the stated rating. Those old school guys were hardcore!
I wonder how the cottage industry folks get their numbers? I’m thinking they have to use some kind of formula and I’d like to know what it is. I’m not thinking there is any kind of malevolence, but it is common to charge more for lower temp bags. That being said, if word starts to get around in our community that some small company’s gear doesn’t work as advertised, it can be detrimental. I’m sure it’s like walking a knife’s edge. What number helps them make the most money from the item without overstating it’s capabilities?
If I was a cottage brand I would understate my ratings a bit like Katabatic seems to do. Just to be safe. EE seems to be dead on comfort ratings. Another comment said Zpacks rates theirs at the limit.
I would think most cottage industry brands would be reliant on word of mouth promotion for sales. It would make so much more sense to under promise and over deliver. If I’m comfortable @ 10° in my 20° rated bag I’m going to sing it’s praises but, if the same bag is rated @ 0°, I won’t be recommending it to my friends.
Which is why EU rules are that the value that a company *has* to provide is the T-comfort and the extreme survival temperature (which happens to be the temperature where women survive, because men can often go lower, but if a woman survive, men survive too), not only the T-limit. American bags usually only advertise the T-limit, which for at least half the population (women) won't work. Having said that, there are men who aren't comfortable at the T-limit either, as they are closer to the T-comfort. It's all really about trial and error to find the sleeping system that works for you, depending on if you're a warm or a cold sleeper.
I always exagerate with sleeping bags, I don't trust the ratings. Looks like I did the right thing. I´m going to check mi Aegismax now, my current sleeping bag. What a useful video, thanks. (Thanks for the metric system too).
Do you know what the avg temp inside the bag that makes one feels “comfortable?” Would be interesting to put my Kestrel in the bag overnight and test the temperature and if I feel comfortable or not.
Great idea. Could use take a thermometer into the bag. I might try it.
@@tomlovesdiy cool + nerdy…😂
Hint: what is the temperature of the human body?
@@markcummings6856 would the actual air temp in the bag be 98F? Wouldn’t you be sweating? Air temp should be cooler?
@@GIRLplusDOGAdventures Yes, no, maybe.
It would actually be hard to accurately measure imo as your body would be so close to the inner “walls “ (if properly sized bag).
But I am intrigued by your question//thought/ idea!
I overheated at -1 in my 30 dollar ozark trail sleeping bag from walmart rated for 10, so I think it definitely comes down to the person using it. I have a high metabolism and run hot.
Remeber a liner can creater an extra 5-15 degrees of comfort to a bag as well as a bivy can add an extra 5-10 plus element protection
Recently picked up an REI Magma 30 Quilt to try out this year, but also been looking hard at the Katabatic Flex 30 or Palisade as the next one to get if the REI one doesn't prove satisfactory enough. Ultimately looking for something that will keep me and my feet comfortably warm down to mid-20's with the addition of my down puffy and/or my down balaclava to achieve that. I want to see if that can be done with a 30 rated quilt because of the lighter weight and lower cost.
I'm measuring 3 inches of loft on my Magma quilt by the way using your paper method. Though once I'm in it, some spots no doubt will be less than that due to stretching from pressure points on my body pushing out on it, like my hips and shoulders when on my side. I also put a sheet of tempered glass (extra phone screen protector) on it out of curiosity and it compressed down to about 2.25 inches.
I've had it out one weekend so far and temps got down to mid 30's. It performed pretty well there with a 3.2 pad. If course, I knew that would be the low and would have taken my 4.2 pad if temp was forecasted to go below freezing and into the 20's.
Spent hundreds on a Nemo sleeping bag. They literally had to lie about the comfort rating. I was completely unsatisfied with my purchase from them.
Actual bag performance has a lot to do with the sleeper, what their wearing, humidity, draft, and how well fed the sleeper is. Not to mention the effects of what kind of shelter you are using and the number of people in it. People use 40f bags on 7000m peaks with proper nutrition (fats before bed), short sleep times, and clothing. It’s just not as simple as this video presents it. The only way to know if a bag works for you is to use it in your intended conditions/sleep system.
I would think that how a material compresses would also affect it's R value. If I was camping in 20 degree temperatures, I would want something good for 10 degrees.
SUPER interesting video! I'll try to remember to measure my bags (certified ratings and non-certified). Would definitely love to see a follow-up and analysis of all the responses you get.
Loving the content!
Reading comments I’m beginning to believe loft has to increase exponentially the colder the temps. Which throws out ray Jardines formula all together
@@MyLifeOutdoors interesting! I wonder if our bags have gotten 'loftier' since he came up with that formula?
Klymit make amazing sleeping bags at reasonable prices
Interesting! I have also seen that the comfort/limit rating by some companies is applied as Tcomfort= average female comfort & Tlimit= average male comfort.
There are three temperature that a producer gives according to the ISO norms: the "comfort" is the temperature at which a standard woman would sleep comfortably, with simple underwear; the "limit" temperature is the temperature at which a standard man would begin being cold, and therefore sleeping in fetal position, but would not wake up for the cold, wearing simple underwear; the extreme temperature is the temperature below which the standard man would begin risking a health damage, wearing a simple underwear. The key is that the standard indications are given without anything more than simple underwear. In normal life, one can bring a silk liner (some 100 grams) and can wear something warm in bed such as e.g. tights, socks, a merino shirt, so the "limit" temperature is a reliable measure of the tent temperature at which one is sleeping comfortably. Layering always work, and sleeping half-naked in a very warm sleeping pad is not a comfortable experience, in a tent like at home. Liners exist for a reason, besides being easier to wash, in a tent like at home.
All my bags are ISO rated. Simple as. Always held up, lowest was -10 deg C in a -5 rated one, was comfy with wool socks, yoga pants, cotton wifebeater and wool cap. No cold feeling whatsoever
I measured my 0 C° OHUSKY sleeping bag, it is 18,3 C° bag. Maybe that was the reason why I was shivering at -1 C°. Thanks
I have a Teton Leef 20° mummy bag. It's comfortable down to the mid 30s.
I have a older 20° F (32° F comfort) North Face Cat's Meow synthetic sleeping bag from 2015. I've spent around forty to fifty nights in it over the years, in a variety of climates and environments. I've always felt like I was slightly cold, especially right before dawn, even when temperatures didn't get down to freezing. A couple weeks ago forecast was a low of 36 F, woke up to a bit of frost on the ground, so I'm guessing it actually got down to 32 or so, but I kept waking up a few times simply cold. Nothing terrible, no shivering, but still annoying. Because I'm a rather skinny Asian, I've always just figured "eh, I must just sleep cold." Well it turns out most of my bag is measuring only 1.5" of loft! Ray's formula would say my bag is actually 40° bag, and the adjusted formua at the end would put it at 47.5°. Those numbers are A LOT more accurate to my experience with this bag.
This really helps me with future upgrade research because I was starting to get worried I'd need to get a bag with an insanely low rating to stay warm at moderate temperatures.
Bag: North Face Cat's Meow (~2015 model)
Insulation: Synthetic
Stated Rating: 20° F
Stated comfort: 31° F
My experience: Always a bit cold at low 40s and below
Measured Loft: 1.5"
If it's a 2015 bag it's possible that it has lost a fair amount of loft over the years.
I made a spreadsheet, I found their ratings. I was very annoyed at how different a "20 degree bag" was for comfort.
I have a sleeping bag rated to two degrees Celsius but has some Gap in the padding.😮 I'm going to have to try to stretch those fibers out.
I’d appreciate if you could try and review a military sleeping bag set up
Unsurprisingly, this function is totally off. I have a -10F Western Mountaineering bag, and it has 4 inches of loft. I've been cold in this bag at -20C. I do move around a lot when I sleep though, and so I think I let too much warm air out..
Have been sleeping winter sleeping bag (Finnish brand Halti) in just under the tarp and on a basic sleeping matt in Finnish winter -25C°. There was snow over 3 feet. I slept wearing only underwear and T-shirt. Slept like a baby.
I have a kelty cosmic 40, EN rated 37 degree F comfort and has 1 1/2" loft
The ratings only matter when considering the full material. Synthetic, good down, duck down etc... as going to give different rating with the same thickness in material.
All sleeping bags I have used have ad extremely conservative ratings. my 13C sleeping bag works fine down to about 0C. I have woken up at -4C because it was simple too cold. But that might have been due to me being sweaty when falling asleep
So interesting!!!
I just got an Enlightened Equipment 20 degree quilt with synthetic insulation. I measured it's loft at 2.25 inches. I haven't had the chance to test it's warmth in cold temps yet. Hopefully I'll be able to get out next weekend.
Probably more like a 35F bag depending on how warm you sleep.