Cocoon Conundrum

> Which sleep system can I expect to comfortably take me down to the low 20's in conditions faced in higher altitudes (

Really, the only way to find out what will work FOR YOU is by experience.

The cocoon 180 quilt probably has about 1.5" of single layer loft, the 90 about 0.8" and the cocoon 60 pullover/pants about 0.6" more or less. Most people will need about 2" of loft to be comfortable sleeping at 20 deg F. So, the 90 quilt plus cocoon pants/pullover will get you down to 40 deg and the 180 will get you to 20 deg. See below chart from "Secrets of Warmth"

Effective Temp Sleeping Light Work Heavy Work
+40F 1.5" 0.8" 0.2"
+20F 2.0" 1.0" 0.27"
0F 2.5" 1.3" 0.35"
-20F 3.0" 1.6" 0.40"
-40F 3.5" 1.9" 0.48"
-50F 4.0" 2.1" 0.52"

The bivy might add about 5 deg of warmth, but could help with draft control if its windy

Everyone's body is a law of physics unto itself, but entropy seems to be an ever present consideration. Those loft/temp values worked for me when I was in my 20s. Now 20 years later my metabolism is slowing down, and I can get by with less food (maybe some 'stored' calories get used up too) and can only eat so much. Now 2-inches of top loft in a quilt or bag is good to 30 F unless I add warm clothes to bolster the insulation. So Roger's advice is relevant. If you are a cold sleeper, or are in a situation where food or energy is low, those numbers James quoted may be for uncomfortable survival and not a comfy night's rest. 3" of top loft for me is now good to about 10 F. Of course, with 2 people in a warm double walled tent that 10 F is for inside tent temps, where the outside could be at 0 F. The only number on that list that looks right to me is 1.5" and 40 F.

I just love how everyone trying to go SUL insists that they can follow a chart to keep them warm.
Effective Temp Sleeping Light Work Heavy Work
+40F 1.5" 0.8" 0.2"
+20F 2.0" 1.0" 0.27"
0F 2.5" 1.3" 0.35"
-20F 3.0" 1.6" 0.40"
-40F 3.5" 1.9" 0.48"
-50F 4.0" 2.1" 0.52"

Even American made sleeping bags with there carppy bag ratings have better loft ratings than the chart above.
I think this must a Ray Jardine chart?
4" may get you to 0-10F.
-50 would need at least double that.

I'm starting to think that the SUL crowd doesn't want growth any more so there coming out with charts like these to have newbie’s try so they'll never think about even going U/L again.

No wonder everybody calls us crazy.

Hi David,

I'm with Roger on this one- temp rating depends on so many factors. But I think that Randy is close to the mark here, at least based on my experience.

I didn't design this stuff but I certainly use it. I have a 60 quilt, 60 pants, and a 60 hoodie and I'd call this a 40deg setup for me. However, at this temp, I'd always have a bivy (unless I'm in a sealed tent) and an extra balaclava to jack up the head insulation. I'm a moderately cold sleeper.

If I were doing 30 deg, I think I'd trade the 60 quilt for a 180 and at 15-20 deg, I might use the 180 and 60 in tandem. But this is only conjecture and based on my personal sleeping.

If I were using it exclusively for tent sleeping, I might choose the 90 over the 60 quilt, but I bought this to primarily use it with a bivy/tarp system.

For me, I'd imagine that both option A and B would be a bit chilly, but I'm a cold sleeper. Choosing 1, it would be A with a very warm pad (at 20 deg, I like the Exped Downmat) and extra head insulation. But that's me.

I hope there's something helpful in there!

I'd sure like to hear your experiences after using the Cocoon gear in the field. I've owned 6 quilts now and the Cocoon is my favorite. A 180 is surely in the future for me. :-)

dj

I agree with Aaron.

If it takes that much Cocoon stuff to keep a person warm at 30 degrees there has to be something wrong with what the person is doing or the insulation currently being used in the Cocoon items, weight per sq yard, is not enough.

The average person posting here at this time doesn't seem to have a very good grasp of what it takes to stay warm when they are sleeping. Most of what I read here lately just makes me laugh. All the answers are here someplace but it also seems very few are doing any digging to find all the really good threads about this subject.

When you find your "Mr Goodbar" you may get a big surprise.

"The average person posting here at this time doesn't seem to have a very good grasp of what it takes to stay warm when they are sleeping. Most of what I read here lately just makes me laugh."

Well, why don't you start a new thread and post your knowledge? C'mon, Bill — be Mr. Goodbar for us! :)

"Passionate" is the perfect diplomatic way to put it..lol. Can't wait to read more.

What shelter is David going to use? I think that is very important to the equation.

My research indicates that a naked sleeper will be warm near the Equator. I'm going to work on scenarios from there for a start.

Hi David,

What are you planning to use for a Sleeping Pad (detail).

What else (everything skin out) will you be wearing to sleep in or have along to use if necessary?

Go over you shelter plans – best case to worst case?

I am going for a walk and will be back in 4 miles.

PS. Can you or someone close to you sew?

Hi David,

It didn't take this long for me to walk 4 miles I just type really slow.

One of the problems I have with the choice of a quilt at this temperature range is they are not very effective at holding your body heat in, there is no in. With no bottom you will lose a certain amount of heat no matter what you do. Using a Bivy and putting your sleeping pads inside the Bivy will help but only a little.

I have stopped using a quilt below about 35 degrees (F). I have gone to a sleeping bag (home-made) with a non-insulated bottom. My Sleeping Pad, below about 30 is a Down Air Mattress with an "R" rating of 9. It is about 3.5 inches thick and weighs about 24 ounces. It goes inside my (home-made) 4 ounce Pertex Quantum and Cuben Bivy. When it is warmer I use one of several different sleeping pads.

I don't know anything about the ID Logan Vest or the eVent Bivy Overbag. I do not/will not buy anything made out of eVent. All the old and nice fleece I own does not go hiking with me anymore. It is to heavy compared to the Down or Synthetic items I now have.

I just had a fresh look at the ID eVent Overbag. Before I would spend what it costs I would take that $220 add the BMW quilt money to it and look for a nice Down sleeping bag.

I did a review of all the numbers for each (A) and (B). Most of this is due to the sleeping pads you say you want to use and the choice of a quilt. If the weather should get below 20 degrees (F) I think you are in real trouble. ! You have to get more insulation under you ! Then you need to test this all someplace where you can bail-out easy if things don't work.

I asked if you could sew and you said no, can you learn? Would you have a sewing machine to use if you wanted to try?

Making Your Own Gear is not Rocket Science.

>>> Still surprising that there is not more 'standard' information provided about Cocoon gear – expectations of warmth given 'this' and 'that.'

I don't see how there could be a standard. Expectations of being warmth would probably have wide ranges. For example, I am a warm sleeper and have the Cocoon UL 60 Hoody and Pants. Doug's expectations and mine would probably differ quite a bit.

I'm following a strategy inline with Roger's recommendation. As the temps get cooler, I'm going to keep trying my Hoody and Pants with my down quilt (No Sniveller) and VAPR bivy under a poncho tarp to test their comfort zone for me.

In addition to the Cocoon's warmth, I considered the weight, retention of insulation when wet, the designer and why he designed them, and value.

All I had to do was eat catfood for a month, but now I also have an inventory of cat stoves : )

Hi David

> If I buy a Montbell SS#3 that is 'rated' to 32, I can have at least some confidence that I have a starting point with which to then build my sleep system. … Clearly not all rating systems are the same and people will sleep 'cold' or 'warm,' but there is obviously a pretty clear average.

Europe now has a genuine human-oriented Standard for the measurement of sleeping bag warmth. This Standard works. A range of American sleeping bags were tested by Mammut in Europe, and over-optimistic claims of up to 18 degrees were found.

Naturally, many American sleeping bag manufacturers do NOT like the European Standard. But this may help you to understand why many 'ratings' are so much crap, and why BPL does not play that game.

Cheers

"This Standard works."

"Naturally, many American sleeping bag manufacturers do NOT like the European Standard"

Why? Because it works? Maybe there are math errors in the study's conversions. This has happened even with rocket scientists – remember? [ 1999. NASA’s Mars Climate Orbiter believed to be lost. NASA Press Release (Sept. 23).

Please elaborate.

It is the opinion of many at BPL that the lack of subjective data on product listings is in the best interest of consumers. When a manufacturer uses subjective data to describe a product it can lead to instances of people putting undue trust in a product. For example a consumer assuming a sleeping bag will have the ability to keep them warm and in actuality will not.

So why, you ask doesn't BPL simply put other commonly referred to objective data alongside the product listings such as CLO values of insulation? Although BPL/BMW has good relations with the manufacturers of such fabrics as Polarguard and Pertex, those manufacturers keep tight lips in regards to most of the technical data of said fabrics. You'll notice that fabric information is limited to weight per area and not much more and that is simply dependent on information availability.

That being said, BPL is currently discussing a means of providing usable data to consumers that will be objective and helpful in making educated decisions in terms of the products you will use to keep yourself warm and safe in the backcountry.

Sam, I don't consider loft or inside dimensions subjective, and those are left out too. People keep asking for footbox dimensions and they're left out in the cold (so to speak) to get that information from other people.

John,

You are absolutely right that dimensional information is not subjective data and that it is information which should be made available to potential consumers.

– Sam

a) Contains around 600g of Polarguard Delta
b) around 450g PG Delta

A TNF cat's meow sleeping bag contains 700g PG Delta and is comfortable to 28F according to the European standard which includes a 15F sleeping pad for all bags (it overestimates lighter bags and underestimates expedition ones that way).
http://www.thenorthface.com/opencms/opencms/tnf/gear.jsp?site=EU&model=AJ6U&language=en

With a 15F sleeping pad a) might be ok to slightly cold at 20F for a warm sleeper and perfect setup.

Specs for (a) Cocoon UL 180 Quilt indicate a total weight of 555 grams (size Long)

Specs for (b) Cocoon Pro 90 Quilt indicate a total weight of 397 grams (no size indicated).

Not sure I would believe 600 grams and 450 grams of Polarguard Delta fill unless the shell fabric has negative weight ;-)

David:

You used MontBell No. 3 as your example of the usefulness of temp rating. I think MontBell has a great system going — and that's one important reason why I own two of their bags.

But methinks that the reason no gear maker — not even MontBell — rates clothing is because the variable conditions of wearers/activities/environment during the day are so much more numerous and more varied as compared to the variables after folks have settled down and tucked themselves into their sleeping bags! If rating bags is hard (and I think it is) — then I believe rating clothing is much harder still — and thus open to much more abuse.

Maybe the only "sort of effective" way to gauge the warmth of Cocoon (or any other brand) clothing is to pick one or two pieces specifically — and do an informal survey here and on other forums. Ask folks what temp. range they would wear their Cocoon XXX — before they feel they need another layer, or something heavier, etc., etc.

As an example, people ask about the MontBell UL Down jacket and Thermawrap jacket all the time. The "concensus range" seems to be 30-40F. With this kind of info, and knowing how comparatively hardy (or not) one is, then one should be able to judge relatively easily.

Lately, I have seen a myriad of oh-so-intricate-and-complicated charts, graphs, and equations on this Board. Frankly, I don't find them any more useful than just looking at loft and asking around for direct experience — then applying the findings to myself.

I have included hoody and pant for both options. They add around 200g of fill.

Makes sense. Thanks for the clarification.

Ben highlights an important issue by pointing out the variability of clothing – a potential flaw with EN 13537.

While in our sleeping gear, don't we wear less clothing when it is warmer and more clothing when it is cooler. How does EN 13537 work that into their "standard"?

From what I've recently read about the "standard", sweating is not considered:

"EN 13537 does take in sweating but only as a simplified calculated value. Sweating can reduce the insulation, particularly at low temperatures. However, very few institutes have or could afford a sweating humanoid manikin and it would be exceptionally difficult to calibrate. The test is already expensive. A sweating manikin test would probably double the cost per test."

Maybe because the "standard" testing is costly and still does not give a good resolution to the issue, are why Americans don't like it. [Note: could be Yanks are much more sweaty and restless sleepers compared to Europeans. This could void the analysis possibly.]

George:

Do you check for tempuratures? 50F can feel very different when you are wet, hungry and tired — versus dry, well-fed and well rested. But won't you say that knowing the temperature can still be very helpful? Certain factors, it's important and useful to have a standard that all can relate to — even if everyone then makes subjective "interpretations".

Be it the "MontBell standard" or the "EU standard" or whatever… if we can have a standard — then at least we can make comparisons across the board. I believe a bag's rating should assume that the average sleeper wears a baselayer — and NOT dependent on the wearer having to don on a down hood, jacket, pants and wool socks in order to feel comfy. If temp ratings are done uniformly to a standard, then we can compare bags across brands — something we just can't do today. And so long as the assumptions and factors behind the standard are disclosed — then we can make adjustments to fit our individual needs.

I think it makes a lot of sense — and is emminently do-able — to have sleeping bag temp ratings. Clothing is going to be a lot harder though…