eVent or DWR for sleeping bag?

[Powder River]

I am shopping for a 0 degree bag and am in a dilemma over shell material. On the one hand, there is the Montbell Spiral Down Hugger 0 which is 2 lb, 9 ounces but uses DWR treatment on a 12 denier nylon.

On the other end of the spectrum is something like the Feathered Friends Snowbunting which is made with an eVent shell, at ~2 lb, 14 ounces. (I called them and the rep said the eVent adds about 1.5 oz over the listed Epic fabric)

EVent may seem like overkill at first but then I realized that out of all the water proof fabrics, eVent is the most breathable. (but not more so than a plain DWR) For instance, FF's other fabric is Epic by Nextec, but reading reviews around the internets it seems that eVent is WAY more breathable. To me, this seems more important than any additional water proofness that it offers.

I guess the bottom line is that I anticipate my tent will always have a lot of condensation, so I want to make the smart choice. It is already an expensive purchase so I am not considering the price differences a factor. Also, 5 ounces seems worth it to me if the tech really is useful. In other words, I'm not considering price or weight, only utility of the upgrade here.

[Mountain Wildman]

Powder River,
I am certainly not an expert but I just ordered the Feathered Friends Winter Wren and Wesley recommended the Nano material. I told him this was for my AT Thru-Hike next year and the website recommends the Event but he insisted that the Nano was the best choice. I took his advise and they are making for me now.
DWR=Durable Water Repellant. (Not Waterproof)
I cannot suggest which choice you should make, Just thought I would post this for you. Hope it helps.

[Tinker]

eVent is a PTFE membrane and requires frequent cleaning to work properly. Lack of cleaning will lead to leakage. Correction: it is WAY more waterproof than any dwr, and WAY less breathable. I have an eVent jacket and it is not much more breathable than my old school Goretex-bonded-to-outer-fabric-with-a-free-hanging-liner Sierra Designs jacket.
As always, despite hype -
More waterproof = less breathable.
Get the lightest fabric available. You're using a TENT - if that isn't waterproof, get a NEW one.

[Powder River]

Very true, Tinker. That reminds me of a time I was at Hudson Trail Outfitters trying to buy a pair of trail runners, and the guy kept trying to push the Gore Tex XCR shoes on me. I told him I didn't want Gore Tex because they get way too swampy and I didn't want to hike with buckets laced to my feet. He told me with a straight face that Gore Tex is the most breathable material there is. I told him it is not near as breathable as regular nylon, and he said no, it is. I then asked him he thought if it was more breathable than a thin wool shirt, and he said yes. I just laughed and walked away. Why aren't we all wearing gore tex base layers then?

But the point here is whether that breathability difference matters in winter conditions, when you are only sleeping. If a winter bag is less breathable, but still expelling your condensation as designed, then is that really a limiting factor? There are definitely good uses for waterproof fabrics, especially when the temperature drops. For instance, while I wouldn't wear gore tex trail runners for summer, I definitely would use gore tex hiking boots in winter.

I guess there are several factors I am concerned about:

1. Because I plan to get a 6'6" bag so I can stow water bottles, batteries, filter etc I am concerned that the extra length will cause the bag to rest against the tent wall, and get wet.
2. In my current bag (Western Mountaineering Ultralite) I experience chills from windy drafts coming through the tent, which go right through the bag. So I want to have a much more robust shell on the bag.
3. If I were on a 5 day trip, and the bag gets a little damp each night from tent condensation, etc and it were winter it seems the feathers would start to freeze, etc without a proper shell.

On the other hand, would a DWR bag work just fine? Choices, choices...

[Tinker]

Reading your above post, maybe you could do with a dwr bag and a Tyvek foot bootie for the bag.
Your current bag is probably just not warm enough - hold it- I just had a thought - what kind of a TENT do you have? If it has lots of mesh, what are you doing camping in the winter with it? If the wind blows through it, cooling your bag, wouldn't a warmer bag solve the problem? Despite the fact that membrane bonded fabrics are virtually windproof, the nylon on your bag, being downproof, should be quite wind resistant.
Any membrane WILL raise the humidity within your bag, resulting in the down becoming damp much more quickly than if it was allowed to pass through more quickly. Even if you have a -60 degree bag, if the temperature reaches 32 degrees F. WITHIN the bag, ice will form at that point in the down. This has happened on a regular basis during polar exploration. Synthetic bags were tried because the down lost so much loft. The synthetic bags froze internally and eventually ended up weighing in the range of 17 lbs. each, if I remember my history correctly. They could not be dried because the weather never got warm enough. This won't happen on the AT, though your bag, once wet, may never dry because the weather sometimes is wet day after day for weeks.
Ok. too much jabbering.

[Powder River]

Powder River,
I am certainly not an expert but I just ordered the Feathered Friends Winter Wren and Wesley recommended the Nano material. I told him this was for my AT Thru-Hike next year and the website recommends the Event but he insisted that the Nano was the best choice. I took his advise and they are making for me now.
DWR=Durable Water Repellant. (Not Waterproof)
I cannot suggest which choice you should make, Just thought I would post this for you. Hope it helps.

Wildman,

They pretty much said the same thing to me on the phone in regards to the 10 degree bag and up. I think he said that the use of eVent doesn't "make sense" for a bag with that rating. But starting with the 0 degree Snowbunting, they only offer either Epic or eVent fabrics (the Nano being special order only). eVent being the more breathable of the two, it makes more sense.

[Powder River]

Tinker, very interesting discussion. I have a Contrail and a MSR Hubba HP. I bought the HP for its supposed warmer qualities, but there are two small windows near the ceiling, one on each side that allow the wind in. Because the wind goes right under the vestibule, up the side of the tent and through the tent, it is kind of wind tunnelish.

So if the down is going to freeze then what about a vapor barrier?

[Tinker]

A vapor barrier will keep all moisture from your body out of the down and prevent it from freezing. I had a Stephenson vapor barrier bag which had a built in vapor barrier and down air mattress. It was absolutely WONDERFUL in extremely cold (10 below and lower) temperatures. It had two removable tops, a thin one and a thick one. I found, however, that the thin one had too narrow of a comfort "window" in warmer weather (it was too stuffy/damp in temps. over 40). so I sold the bag. A vapor barrier liner (VBL) will work in extreme cold as long as you're willing to feel damp, even though you are warm, and not wear much inside it (meaning you'll need to keep a warm jacket nearby when you get up, and THAT will take a while to warm up - I used to drape my down jacket over my sleeping bag to keep it "reasonably" warm).
The other option, probably preferably, comfort-wise is to use a hot water bottle when temperatures get below what you expect them to be. That is the method I use when I'm not expecting extremes but the temperature is less than anticipated.

[Mountain Wildman]

Thanks Powder,
I hope I am not being mis-led by FF, I called with the intention of ordering the Epic or Event material until he assured me the Nano was the best choice.

[Tinker]

I probably should add that I have two FF bags - A Great Auk and a Rock Wren. Both were purchased in the mid 1990s. Both have the lightest nylon available at the time. I chose not to go with Gore-tex after reading up on its use in down jackets and sleeping bags.

[Matteroo]

what are you using the bag for?
i have a FF raven with 2oz overfill and eVent fabric. I got it for winter use in the Pacific NW volcanoes and mountains, and for use in snowcaves/bivys, or shoulder season sleeping out without any tent/bivy/etc. Now to think of it, I probably could/should have gone with epic, but because the bag would be around climbing gear, crampons/ice axes, etc, I wanted something tougher. Nano is an awesome treatment/process in the fabric itself--it is permanent. Mammut uses the Nanosphere treatment on their jackets and ice climbers and other fairly extreme users rave about the waterproofness and overall greatness during most winter use of items with this treatment.

I myself am not worried about 'the down getting wet from my body's respiration' or whatever when using it for a 1, 2, or 3 night trip during the winter when it is 20-30 degrees out. If it is a lot colder than that or I am planning on staying out for a week, I add a western mountaineering hotsac vapor barrier. The thing is, if a little condensation comes from your body into the down on a 1 or 2 nighter, i have no reason to believe it would be noticeable or impact overall performance, and it will not damage the down and will evaporate. That at least is how i am operating.

if you're using it for more days in a row, get a vbl anyways I'd say.

one of the biggest gripes with the WM ultralite my fiance has during her thru is that in a singlewall tent in the morning or during rain the condensation would come on the bag and make her hyper/anxious about the down being wet. I dont think it was a big deal but the addition of a simple fabric like epic or nano would have taken care of that. Event is over-kill for in the tent but here is the truth of the matter: at the end of the day unless you want to obsess or buy a computer and then look online two years later and see how cheap it is to beat yourself up...you will be happy with event, epic, or nano. All will be better than the fabric the ultralite is made out of (in terms of water resistance/proof. FF will not steer you wrong--they are a great company. They suggested the nano because it is the most lightweight (you are thru hiking) and water resistant. if you are just a cold sleeper and want better than you have now, epic or nano will be better.

that said, epic and nano are going to be more 'breathable' than event, no matter what you read. i have an event shell from RAB company in the UK. eVent IS better than goretex pro-shell or whatever, but no material is a panacea. That is why there are pit zips even on softshells. In due time if the materials that have pores that open up and change depending on humidity and heat get developed to be at the sophistication of something evolutionarily designed like skin, then maybe that will be a panacea. until then it will continue to be small steps every few years towards more and more heat retention/venting...more vapor transport...more wind blocking...softer materials..more waterproofness, etc. One must admit compared to 20 years ago the fabrics have come a long long way.

[Dogwood]

Powder River Whoa! You're starting to over think things and go down tangents. You are doing what I've been know to do myself. You're making things more complicated than they need to be!

If you are planning on sleeping in a sleeping bag inside a WP tent, I don't care what kind of tent, and I don't care if it's a down bag either, you don't really need a fully WP sleeping bag to avoid condensation issues from your tent! Overkill! Even for winter! Even if your sleeping bag touches the interior walls of the tent, which it shouldn't, a WP sleeping bag shell is not necessary IF you plan on purchasing a quality sleeping bag w/ a quality DWR shell, like is available from a WM, MB, or FF bag. A quality DWR sleeping bag shell is really all you are most likely going to need to protect the down from condensation. It doesn't sound like you are going on a long arctic expedition(you mentioned 5 day winter trips). And, if you were planning a longer winter trek w/ a down bag on a trail like the AT you will have mutiple opps to visit a laundromat to dry the down out from accumulated condensation. But the DWR should provide the down protection you need under the conditions you describe.

I don't think it accurate or fair to compare a WP shoe, with any kind of WP technolgy, with a WP sleeping bag if you are planning to use the sleeping bag inside a WP tent. Don't confuse these different situations. Different scenarios! Different conditions, requiring different ways of looking at the situation.

You also mentioned windy drafts/chills coming through the tent and sleeping bag. When you say that I start wondering about avoidable factors like tent and campsite selection that you may be making. I also wouldn't confuse quality acurately temp rated sleeping bags of 0* and something like a 20-25* WM Ultralite. Designers have different goals in mind for the avg user under these different temps. For, example, all other things aside, a 0* bag is going to be less drafty than a 20-25 * rated bag. As example, a 20-25* bag may have a less substantial DRAFT tube or perhaps none at all while just about any high quality 0* rated bag is going to adequately address this issue by having a DRAFT tube or more substantial one or in someway avoid the same drafts. If you are finding unacceptable drafts w/ the WM Ultralite this may be something to think about. You may need to go to a warmer bag, not the same bag w/ a WP shell. One quick way to solve most of this issue is wear warmer clothing or perhaps you're clothing shell inside the slepping bag to avoid drafts. I would also examine my tent and site selection, as mentioned above, to avoid drafts.

Don't confuse the condensation that can come from your body while inside your sleeping bag with the condensation from external sources like condensation from the interior walls of a tent. I think it should be pointed out that even w/ some(most?) bags w/ a WP shell the interior sleeping bag shell(what's next to your body) isn't always, and not usually, is WP. Then it becomes a matter if you want to protect a down bag from body condensation by sleeping in a large impermeable bread bag(vapor barrier) and if it's really necessary for someone that typically goes on 5 day winter treks sleeping inside a WP tent. Again, especially for short duration treks, it's mostly overkill. IMO!

[Powder River]

Tinker, Matteroo, and Dogwood,

Thanks for the great responses. I am definitely reconsidering my need/want for the eVent bag. I agree that a DWR bag definitely is all that is really necessary for my uses, especially if it can cut weight. But this all came about because Feathered Friends doesn't offer DWR for their 0 degree bag as a standard option, and is a custom option only. The options are Epic or eVent. I like the Feathered Friends bag the best out of the following three:

Montbell Spiral Down Hugger 0 Long: 2 lb 13 oz
Feathered Friends Snowbunting Long: 2 lb 15 oz (Epic) 3 lb 1 oz (eVent)
Western Mountaineering Kodiak MF Long: 2 lb 15 oz

The problem is that the Kodiak has a 66" girth, which is way too big. I fit fine into my 59" WM Ultralite. I'll be getting the bag a little long for me anyways, so I have room to stash things in the bottom. So I don't want it too big in two dimensions. That leaves something like the 5 degree Antelope MF from WM, but I would rather have a temp rating of 0. However, the Antelope remains the closest in my consideration of alternatives.

So that leaves the MB vs. the FF. I am a little uneasy with the spiral technology at this temperature. I own a MB SS #5 and hiked most of the AT with it, but it has a lot of distribution and clumping issues. That is fine because it is only a 40 degree bag, but when it got into the 40's I was cold. Also, the coating is the exact same as on the spiral stretch, the spiral having an even thinner nylon. I definitely was never impressed with the coating, in fact I'm not sure I remember ever seeing it bead water. If it got dripped on, then the bag simply got damp. So this experience definitely has me leaning towards a more hefty DWR, at the very least.

So this brings us to the feathered friends. It seems to be the best cut and design of the three bags, and the fact that its hand made here in the USA is very nice too. The choice is the fabric. I have read a lot of conflicting information on which fabric is actually more breathable of the two, Epic or eVent. Despite what you said Matteroo, I have seen far more posts claiming that eVent is more breathable. But I am willing to put more credence with this article:
http://www.prolitegear.com/site/xdpy...034/index.html

I heartily agree that eVent is completely overkill, but if it is more breathable than Epic, then it is the clear choice for the Feathered Friends bag. For two ounces it seems worth it to have the more breathable of the two, and I consider the WP quality a bonus only.

Back to my original question, I am really not trying to justify having a NEED for eVent fabric on a sleeping bag for my uses. Rather, given the situation with the FF options, I am merely trying to figure out if it would be a detriment. In other words, why not? If eVent is up to the task of expelling the amount of moisture it needs for the bag to function properly, then where's the problem? If it is not up to that task, and eVent > Epic in that category, then clearly I need to abandon the idea of getting a Feathered Friends altogether.

[ARambler]

I was reluctant to respond because I still have less than 4000 miles on my FF event Humingbird. I am shocked at the ratio of exerience to smarts in this thread.

FF has been making GoreTex bags for about 20 years. Event is more breathable. Why is breathability an issue???? What are the circumstances? Hauling a lot of wet gear in the bag?

It may be all placebo, and all of my nights have been out west (drier), but the event seems much more windproof, and condensation repellent. That said, most bags are good enough at repelling condensation. I would still be worried about puddles of water, because the event seams are not sealed.

Does anyone have experience with this extra length idea? If you have a 1 to 2 inch jap between your tows and gear, the gear is pretty well insulated from you feet. If there is a continuous tunnnel, you have dubbled the heat transfer area that your feet have to heat up. I would get a wider bag and try to keep critical gear next to me, maybe only a little before I get up. I don't have much experience below freezing.
Rambler

[Dogwood]

I'm not really sure why breathability is an issue either when one considers how you plan on using your sleeping bag inside a WP tent. Perhaps, some are looking at the issue of body moisture getting into the down on longer winter trips and the abilty of the bag to transfer that moisture through the bag and out of it through the outer shell. In that case breathability ability may be an issue. But again, if one is so concerned about moisture entering into the down from the inside of the sleeping bag on long winter trips(which it sounds like you don't plan on doing) you could use a VB. Again, I think you are considering problems that MAY develop on trips that are not typical of your trips!

Powder River, I think you are over looking your options of reliable water resistant shell materials/fabrics at FF. What's wrong with the water resistance of Nanosphere fabrics offered by FF? Your call, but Nanosphere seems exactly what you could use to repel condensation from inside tent walls and still achieve the maximum amount of breathability that you desire! Did you read FF's explanation of nanosphere technology under fabric choices offered? Seems the obvious choice to me for eliminating the problems that you are concerned with or MAY develop w/ your set-up and usage!

[Powder River]

Dogwood,

Yes, Nanosphere seems like just the stuff, and it would render this entire discussion moot. But the problem is they offer it only as a custom order, which costs even more $$$, and takes something like 4-5 weeks or longer. So of the two remaining fabrics, eVent seems both more breathable and more waterproof, neither of which seem like bad things. Currently my head is starting to hurt figuring all of this out and I'm starting to lean towards a WM Antelope. =)

ARambler,

I have never had an long bag, but I currently have a 6 foot WM bag and I am 5'10". The width of the footbox of all of these bags I've been looking at are 39". In my WM, I have no room for a Nalgene bottle, except maybe up behind my knees. I'll throw things like batteries and a filter in the bottom, but there really isn't room below my feet to speak of and I usually wake up to find those items have migrated to under my arm or somewhere. So yeah, an extra 8 inches seems like a lot but I've heard a lot of people recommend it.

[Dogwood]

I can't speak to custom manufacturing times at FF but are you sure that FF has quoted a higher price for Nanospehere in the Snowbunting than Event? I don't find that likely and would find that astonishing if that's the case! I also see in their other bags that Nanosphere is quoted as the same price as Epic.

As far as someone recommending a larger bag for winter be careful how you approach that. While it might be advantageous to have a SLIGHTLY wider girth/hip sleeping bag if you plan on wearing puffy down layers to sleep that you don't want unduly compressed or you are a wide shouldered or larger girth or wide hipped person, the length is a different story, especially w/ a cold weather bag like a 0* bag. If you are 5'10" and only wanting to store a Nalgene, batteries, and/or small filter(?) inside your sleeping bag a 6 ' long bag should suffice! Seems like you would not want all that extra space to have to heat up when you are purchasing a bag designed for optimal thermal efficiency and taking into account your previously mentioned concern about feeling drafty! You are 5'10" and wanting a 6'6" bag when a 6' length is available? Huh?

[Snowleopard]

I have a Feathered Friends 20F bag and it is excellent. It doesn't have any fancy fabrics for the shell because they were more expensive and I couldn't afford them.

From my reading, Epic is supposed to be more breathable (but excellent water resistance) and Event more waterproof. If you're going to be using your bag outside with no tent in the rain and snow (bad idea), event will be better. But if you're considering that you should at least be using a bivy bag.

Size: wider is better if you're going to push the rating of your bag by wearing puffy clothes or using a liner inside. My bag is rather tight and I can't really do that. On the other hand if you're planning on going much below 0, you'd do better to get a warmer bag.