EN 13537 and LOFT

del

> a beautiful, extremely well made, overstuffed quilt that failed to keep me warm at
> it's rated temp.

There are several factors at play here.

First of all, if the quilt does not have an EN rating then you have no guarantee of performance. Sadly, it must be said that American temperature ratings have been found to be up to 12 C wrong when tested to the EN13537 standard. This is not to say that your quilt suffers from this, just that it happens, and in general we do not believe claims not supported by proper testing.

Second, if the quilt is all that good, then maybe something else is the problem. If your mat is not up to scratch, no amount of quilt will keep you warm. You did not specify what mat if any you were using. Different mats have huge differences in performance.

Third, you did not specify whether you are cowboy camping, in a bivy bag, under a tarp, in a mesh-type tent, or in a proper double-skin winter tent. The air flow over the quilt will have a huge effect on how warm you sleep.

Fourth, were you wearing any clothing under your quilt? The EN13537 standard assumes a full set of thermals. On the other hand, wearing so-called compression-clothing is guaranteed to make you cold: it restricts your blood flow.

Finally, you need to specify what sort of evening meal you had. If you didn't have enough food, you will be cold – period.

Cheers

Hi Roger and Rick, thanks for your comments.

I've done further research on BPL and found the following 2007 thread which seems to provide a nice chart with some useful values measured by ( no surprise) Richard Nisley:
http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=5625&disable_pagination=1

Roger,

To answer your questions:

Ground insulation: 5mm MEC yellow evazote (R=0.7)+ Thermarest neoair x-lite short(R=3.2) additional lower leg/foot insulation from pack…(R=?, some foam in my backpad). Lower legs definitely felt cold.

In a bivy under the stars most nights above 10k feet. Clear skies, some nights very windy, but usually in sheltered locations aways from katabatic cold air currents. Temps hovering near freezing point+/- 5D I would estimate. Under a tarp a few nights. No noticeable difference.

Clothing worn: capilene long underwear, thick wool socks,l/s wool top,fleece balaclava + R1 hoodie + MB hooded thermawrap.

Food: I lost much weight on this trip ~12 pds. We had big, long days and we were constantly eating, and especially to capacity at evening meals, includng a snickers bar immediately before turning in. It was probably impossible to replace calories given the pace we were consumming them. Well hydrated.

I'm looking to get a conservative estimate of what I would need for temps in the 20's given that I sleep cold, usually travel and camp at elevations above 10k feet, push to my limit and canlikely not carry enough calories to make up for the loss. I'm shooting for something in the 3"-3.5" (single layer) range.

if you are looking for "comfort" rating .. itll be 10F less than the lower limit rating in general … so i suspect for most manufacturers youll need somerthing 10F lower than their generally advertised rating … assuming that most are rated to the lower limit even if accurate

also the partial pad probably didnt help … would you get sufficient R value with your pack on a thin evazote? … your legs feeling cold probably didnt help out

also a snickers bar doesnt help too much before bed … eat something with a high fat content, sausage or cheese … its well known among climbers that if you want "keep you warm food" on a bivi to eat fatty, not sugary foods

if you are constantly malnourished you may well never feel truly warm and need much more insulation at night that normal … you losing weight means your body is burning itself up for energy

also make sure you get your quilt warm before sleeping … either sit ups in it or a hawt nalgene

are you male or female …. if male are you a skinny male with little body fat? … if so then you definitely want the comfort rating

did you wear a VERY warm hat with your quilt? … if the rest of your body is bundled up and all you have is a beanie, then most of the heat loss will now be through the head

i assume you had problems near the lower rating of your quilt?

the bottom line is that you dont know what the problem is … before spending more moola i would try to figure it out on a short trip or in your backyard first

start with the fatty foots, something very warm on the head, and simulate a full length pad (use more foam in the backyard or a bag full of clothese) …

if that doesnt work then it probably means you need a new pad/bag/quilt …. or you can get a summer synth overquilt to boost the temps

but figure out whats wrong first … thats the basics of any troubleshooting

on a side note the problem with these "untested" quilts is that you dont really know how "warm" they are … all you are left with is BPLers giving their subjective impressions …. you dont know if they sleep warm, have a lot of body fat, if they realy tested it down to the proper conditions, etc … and there IS a bias towards cottage gear where almost no one here will post a critical review (and we all know cottage gear aint perfect)

basically you are accepting someone elses word that its "warm" enough for YOU … en-ratings at least give you a solid reference''

and im the owner of a EE 20F quilt

;)

edit …

read this

http://www.mammut.ch/images/Mammut_Sleep_well_pt1_E.pdf

and this

http://www.andy-kirkpatrick.com/articles/view/maximising_your_bags_warmth

I sleep cold and I found that a conservatively rated 20ºF quilt and an R5 pad keeps me warm at or around freezing.

I found that I often feel cold at similar temperatures without such a warm pad (Neoair XTherm), and if not sleeping on the ground, but on a raised platform such as a wooden lean-to, I will still feel cold from below, even with that warm a pad. I have spent many nights on snow with the XTherm comfortably warm, but in similar conditions on a raised wooden platform with the XTherm on top, far less comfortably.

Eric,
Thanks for the comments.

I've sold the quilt so replacing it is necessary. I'm male, with fairly low body fat. I run very warm above freezing and during daytime regardless of temp. Nights below freezing I run cold.

I'm fairly certain I need more insulation in the quilt hence I'm looking for accurate specs. I think the recommendation of fattier foods is probably a good one. As well as a full lenght pad. Head insulation was adequate. For my metabolism and circumstances I'm fairly certain I just need more insulation. I've slept in colder temp with lighter quilt without problems on shorter, less intense trips at lower elevations, with less wind exposure. This particular set of circumstances just requires more insulation and I'm hoping to pickup a warmer quilt.

Looking at an EE 10D Enigma 850DT with 14.45oz of down and 3" of loft, or the 0D version with 3.5" of loft. Katabatic Sawatch also looks good with a collar and overstuffing available. Their loft appears very good and the temp rating very conservative, but price is higher. Both would be lighter than what I was using and hopefully warmer.

Edit: removed comments about zpack quilts.

Stephen what 20F quilt are you using?

>Stephen what 20F quilt are you using?

Enlightened Equipment RevX. I am a big fan.

I add 10f~15 on to the ratings of my WM bags and EE quilts.

I stopped factoring down clothing in to my sleeping system in wintershouler season as 3 times in the last year I did it and it was a very close call on comfort due to the temps being 20f colder than forecast.
I now take a bag/quilt more than adequately rated for the conditions as well as decent insulated clothing, it does get down well below 0f on most of my winter trips.

You might need more loft, but also consider:

1. It sounds like your body was pushed to the fatigue limit and couldn't generate as much heat as it normally would.

2. The surface you're sleeping on makes a huge difference. Snow or thick leaf/pine needles is more insulating than a wood or rock surface. Even worse is bare frozen ground or ice. My Exped Downmat with an r-value of 5.9 was barely adequate on frozen ground with just below freezing (25F) air temps and an EN-rated 0F mummy bag!

3. What about drafts? I don't like to use a quilt below 40F, and I definitely wouldn't wnat to use one below 20F.

What Andy says about frozen ground is very true, all winter I use a full ridgerest under a dowmat 7 Ul
And a half one under a synmat ul7 in shoulder season.

I, too, am a cold sleeper. I tend to take a bag rated for 20 degrees colder than the lowest expected temp. If I try to use the actual EN rating, I'll definitely be cold and that means I won't sleep. I also wear a down hood and down booties, thermals, and if I'm still cold I'll make a hot water bottle to take inside my bag with me. Cold sleepers have to plan around that. Oh, and if it's cold and I'm using an air mattress like you are, I'll carry a z-rest to top it with to reduce my heat loss to the cold coming up from the ground through the pad.

Loft is only one of the measuments of how warm a bag/quilt is. Thermal resistance is another. IE the material composition of the the fill, itself. Down is fairly high in these numbers, too. Anyway, strictly looking at loft will lead to an inflatable bag over you which is NOT all that warm as an example. Convection/conduction also needs to be minimized.

But, I believe that the entire sleeping system are let down in two areas.
1) Pad
2) Food

Using a quilt at or below freezing always means a good ground insulation. As was said, an R5 is considered the base starting number for winter camping. There is some overlap at 20-30F. It was also mentioned the ground cover. Forest duff is better than rock or ice. A lean-too is like a hammock with cold air allowed to circulate under you. In a dry area you might scrape together 6-10 inches of duff to help. But your pad is only an R4 or so, and, with a quilt, it needs to be full length. Raw conduction will cause you to bleed heat away rather quickly, faster than it could be replaced if you are cold. It *might* not be the quilt. But if you get a few drafts besides, you WILL know it.

Food, well others have said a lot about fatty long lasting energy. You needed more food… If you lost 12 pounds in 4 nights out, WOW! Yup, you will get cold.

The entire sleep system is rarely considered. It consists of a hood, body covering and a pad. Even compressed, a 1/4" of feathers supply some insulation. A bag will prevent all drafts. The R5 I mentioned was the starting number. If you want to sleep in a lean-too or on other more conductive surfaces, you will need more. Nothing new here, sorry. Just re-emphasizing what others have already said. Your bivy is probobly pretty good at stopping drafts, so I am assuming the above two failure points.

Hi MG

Others have made some very good points. Me, I would target the food you were (not) eating. Not enough, by a long shot, especially for alpine regions in the cold. I am not sure that adding insulation can overcome that.

As a secondary I would look to upgrade the mat a bit. We like the Exped Synmat UL7 in the cold – but not in the snow.

Cheers

"Food, well others have said a lot about fatty long lasting energy."

Fat is commonly assumed to produce the most heat during digestion, but in reality it is protein which requires the most energy to digest as a percentage of the amount consumed and takes the longest to break down. For this reason, it is better to consume a substantial amount of your daily protein with your evening meal if the goal is to use food as part of your sleep system.

"A commonly used estimate of the thermic effect of food is about 10% of one's caloric intake, though the effect varies substantially for different food components. For example, dietary fat is very easy to process and has very little thermic effect, while protein is hard to process and has a much larger thermic effect.[3]

The thermic effect of food is the energy required for digestion, absorption, and disposal of ingested nutrients. Its magnitude depends on the composition of the food consumed:
Carbohydrates: 5 to 15% of the energy consumed
Protein: 20 to 35%
Fats: at most 5 to 15 %[5]"

http://en.wikipedia.org/wiki/Thermic_effect_of_food

A good balaclava is what most of us use for cold weather sleeping.

But a balaclave with a face covering THAT STAYS PUT is just as essential. Blood supply to the face, as it is with the rest of the head and neck, is where most heat can be lost due to the very low to no vaso-constriction in that area of the body.

BTW, using a woman's self-inflating Thermarest mattress may help since the mid section of them is better insulated than men's pads. The weight penalty is slight.

Tim, interesting article. So, basically this is suggesting eating an oz of jerky before heading to bed. Hmmm, likely some fats, too, since the warmth would wear off after 4-5 hours.

" But a balaclave with a face covering THAT STAYS PUT is just as essential. "
Eric is so right about this (and the womens T-rest trick).
a good/easy place to start nity-nite warmth is with a silk scarf. i got one, folded it in half, sewed one short side and half a long one. now i have sort of a cape, like one of those disgusting hospital gowns that wear backwards.
i can wear it open in back, and it drapes over the full of my face and breaths enough to allow sleep and some vision. or open in front and just leaves my mouth open to air.
for some reason it gives warm INstant. even if i simply lay it on my pillow, it stops heat loss to the pillow.
even if just taking a nap on a gravel bar, i toss this pupply over my face, and the world is nicely darkened and a bit warmer.
the dear little thing weighs about 0.3 oz. would not camp without it.

cheers,
v.

ps. peter being old school … for all the hassle low heat's causing you , ya know .. just get a tent, eh.

"So, basically this is suggesting eating an oz of jerky before heading to bed. Hmmm, likely some fats, too, since the warmth would wear off after 4-5 hours."

Fats, too, for the calories, but they would be broken down much quicker, with less thermic effect, than the protein and thus their thermic effect would wear off quicker as well. It's all related to the relative complexity of protein molecules compared to fat molecules, and the relative amounts of energy required to break them down.

Can anyone recommend a good balaclava for cold weather sleeping?

I just ordered a 30F Zpacks bag/quilt and am really hoping that it does the trick. I have a ~ 10F Marmot bag that serves me well in colder weather but is too large, heavy and warm for most 3-season camping so I picked up the Zpacks to fill that role.

My combo for cold weather pads is a Thermarest Ridgerest under an exped downmat. I've been toying with the idea of picking up an Xtherm to drop a little weight but keep a decent R value.

I always add 10* to a quilt.
Then again I make my own gear and what I make as a 30 degree quilt, others sell as there 20 degree model. I do have a 1 off EE 20* quilt and that thing has a crazy amount of loft comparied to my 30* quilt. Then again, my quilt has way better draft control.

Even with the added 10 degrees that is with a jacket worn that is warm enough for sitting around in before I go to sleep. This is sleeping on a 1/8" closed cell pad.
I find that above freezing, an 1/8" CCF pad with another 1 ounce of down in a quilt will be warmer than a normal 15 ounce inflatable with one less ounce.
I also make my quilts with an extra 10" width of a single layer of fabric on each side to make it 10X easier to tuck under you as well as staying put when you turn to your side so you don't even have to re-adjust.

A warm meal will easily add 10-15 degrees of warmth to you. I say this as in a 1000-calorie meal within 30 minutes of sleeping. I sleep very cold as well, but with all the calories I eat before I sleep, I now consider myself an above average warm sleeper.