How does pertex (quantum) endurance fare as a sleeping bag shell? I'm shopping for a new bag (or, ideally, two - 3-season and winter), and, as my current quantum down bag was quite easy to get damp, I thought about something more water resistant. Pertex Endurance bags had been present for some time, but they seemed to be marketed mainly as bivy & sleeping bags in one, for sleeping outside.
I plan to use the bag in a tent, so it won't be exposed directly to rain or snowstorm, but I'd like something which could withstand water droplets from the roof, snow on the floor and brushing against damp tent walls. I always found the hood and feet damp in such conditions.
I understand the fabric was primarily designed as garment shell, where increased snow/water resistance is much more needed, and I have been wondering if it doesn't introduce more problems then it solves by reduced breathing and freezing of condensation inside.
Now I see that RAB produces quantum endurance bags and hope that some of you had occasion to use them and could say if it performs better in such conditions than classic quantum or microlight, and why chose it.
I've had a Rab Quantum Endurance 250 for a few years. It was my main bag from March to October. I now use a quilt because i like more room. I didn't find any downside to the Endurance coating. It was used regularly for everything from tarping to 2 week backpacks. The bag has often been in very wet conditions, and it performed great. Sometimes the outer fabric would 'wet out' at the foot, but only once did the down get wet. That was because the foot end was lying in a pool of water that had gathered during the night, under a tarp.
I would recommend the bag to anyone looking for something that will perform in damp conditions.
Marcin, the Missus has a Q600 Endurance and the only downside seems to be the slight extra weight over the plain Quantum. I use an ME Lightline which has a similar shell (Drilite Loft) and again no particular issues in several years of use. Breathability will be slightly less but, like Mike, we haven't really found it an issue.
We chose them on a "just in case" basis, as we occasionally have them in places like snow holes and leaky bothies. No real regrets.
Pertex Quantum is a water resistant shell. Dependent on which vintage you choose this should be either around 1000mmHH or 1500mmHH. As many will be aware this is not far off being water "proof" by BS Standards.
There are several available from various manufacturers, with subtle differences. PE like any other water resistant shell (Drilite Loft for ME) offers substantially better resistance against water entry. The trade-off is that they are heavier - at least 1/3 but possibly more and they are less breathable. Typically weighing 55-70gsm vs 30-40gsm. They will have limited pressure resistance to water (so no lying in wet puddles in snow-holes) but will happily repel heavy condensation, spilt mugs of tea and melting snow.
The weight issue is questionable. Seriously you are looking at no more than 150 grams extra throughout the whole bag. Damp down weighs considerably more!
Breathability? Well any water resistant shell (no more than 1500HH or single inner coating) should have exceptionally high breathability, in that condensation will amount to very little on the inside of the bag. Only in exceptionally cold conditions is this an issue in which case vapour barrier linings are required. This is all down to the dew-point inside the bag, 35c next to skin lets say, -20c only 6 inches away - thats a steep temperature gradient in anyones book - if moisture does not escape, water droplets form deep within the insulation and freeze. Hence why most use water resistant shells not waterproof.
Is it needed? In cold, still conditions, with long hours of darkness where you are in a tent for 12 hours, you will get condensation. The top of the bag will become damp due to exhaled breath and the footwell will also get damp. Condensation dripping off the roof of the canopy will at best freeze where it is, at worse drip onto your sleeping bag. So a WR shell is an absolute must for winter. You could survive the odd night without but prolonged use is difficult.
Richard Talbot - Product Manager - Mountain Equipment
This is the problem I'm running into using the winter down bag I bought here in China. There's plenty of insulation, but no water resistant shell. The first morning is OK because the moisture's just frozen onto the top of the bag, or within the down itself, but after a few nights at -10 to -15C (inside the tent), cumulative moisture build-up severely reduces the warmth of the bag. I'll stick with it this winter, but have resigned myself to buying a new bag next year with a decent shell.
Interesting reading there from Richard and Montgomery, thanks.
If I'm understanding things, a winter down bag needs to resist to varying degrees both moisture from within and moisture from without....
Moisture from within comes from my perspiration, and I suspect the biggest single thing I can do to minimise this is to avoid exhaling inside the bag, and also regulate my temperature so I'm not overheating? But assuming I'll perspire to some extent then it's down to the climatic conditions prevailing whether the moisture will condense inside the down filling? I could prevent that by using a vapour barrier layer to hold the moisture close to my body and not let it into the down but otherwise, as I read it, whether the bag's outer is water-resistant or not makes no real difference - if anything a non-water resistant shell will breathe better (significantly or not?) so may help. Have I got that right?
Where a water-resistant shell clearly will help is in preventing moisture from without (condensation, frost, spills etc.) from penetrating into the down filling. Richard, you suggest maybe 150g weight penalty for such a shell.... but presumably the same protection can be provided by using the sleeping bag inside a breathable bivi-bag or, perhaps more equivalent since we're not talking about needing full waterproofing, a water-resistant sleeping bag cover? Given that several of these have appeared which weigh sub-200g (some US-available ones significantly less), perhaps such a cover is a more versatile option since the decision to carry that weight or not can be taken acoording to the bag's usage from trip to trip?
Any thoughts anyone? I'd just like to make sure I'm understanding the performance issues that need to be addressed. But if I am then I can see pros and cons to either solution.
The weight penalty on my bag was only about 30g if i remember right. Rab has changed the specs now slightly. I'm sure the Q was 650g, and the QE was 680g.
The water vapour condenses at the dew point. Where this is, depends on the temperature, and in the UK, is usually outside the bag, if using a tent.
For UK use, i would worry more about protecting from condensation and spills. If you are in much colder temps, a VBL will protect from within.
A waterproof/breathable bivvy-bag on a non-water-resistant shell could cause more problems. Condensation that formed on the bivvy-bag would be in constant contact with the sleeping bag.
A water resistant bivvy-bag would be better, but it is still offering moisture another surface to condense on.
The area around the hood gets wet externally; breathing out leads to condensation which is then transferred to the down because the shell's not w/p.
This w/end it was cold enough that all tent condensation in the morning was ice, but when you start cooking this turns to water...exacerbated by the crappy design of the Voyager Superlite in several ways:
a) flat roof = big drips
b) mesh panels at foot/door are an ice trap (I'll take a pic this w/end), accumulating ice which then cascades all over you when you move or open the door.
All this condensation melt would stay outside a w-p/r shell, but is absorbed into my bag. The problem's compounded when you pack the bag away wet, as you must sometimes do. I know from experience (with my Montbell UL2, and the ME Glacier [Drilite fabric] I had for 11 years before that) that this is much less of an issue with a decent outer shell - you can wipe/shake off moisture so it never gets to the down.
Montgomery, which bit of your observations couldn't be dealt with by the addition of a water-resistant cover to your existing bag? Possibly the breathing out near the hood, unless the cover could be closed up very much in line with the hood opening...?
Mike, If I've understood Richard correctly, any Quantum fabric has a weight penalty on account of the water-resistant coating, so while the penalty for stepping up from 'Q' to 'QE' may be around 30g, there's a larger penalty for moving from 'nonQ' fabrics to 'Q' in the first place.
And you say that for th UK you consider condensation (dripping?) and spills to be more of a problem than the dewpoint occuring inside the bag. I'd agree. So a water resistant cover would keep them on the outside and not in contact with the sleeping bag.
I'm just trying to get clear in my head where a separate cover sits in terms of performance and trade-offs compared to integral water-resistance built into the bag. It's just that I've used down bags happily for nearly 30 years and only one (and that by accident) has a Drishell outer, but I've not had serious issues.
If you are careful, and sleep mostly in double skin tents, then it shouldn't matter too much in the UK if you have a water-resistant cover, i wouldn't think. You're a pretty experienced camper Matt, and probably act automatically, when looking after your bag in a tent. A novice making the switch from synthetic to down, might be glad of a water-resistant shell. I like water-resistant shells, as i tend to sleep in a variety of shelters.
The Quantum Endurance vs. Quantum weight penalty for 3-season (or 4-season) bags is neglible, 32g/m2 vs. ~50g/m2 amounts to no more then 80g per bag, which is several times less then any water resistant bivy I know of (although if you could recommend something really light, I could give it a thought). So, unless in some conditions having a PU coated bag is a strong drawback (in which?), everything speaks for the integrated solutio.
I'd like to clarify what we mean here by water resistance.
I understand, by the quoted waterproofness, that you in fact mean endurance coating here? Plain Quantum has DWR and thus can be claimed water resistant (my Quantum 300g is much better in scheding water then my 800g with crappy shell I plan to replace), but the bag still gets damp from pressing against damp tent walls or melted bits of snow on the floor.
Montgomery and the rest: by non-w/r shell you mean to replace did you mean something below Endurance, or even below Quantum?
To sum up: nobody said anything against endurance, and the discussion melts down to whether it really makes a difference and in what conditions. I'll try to pose some more specific questions then, maybe they'll help come up with some conclusion:
1) will Quantum Endurance resist water water pressure resulting from sleeping against wet tent walls, or on the floor with snow on it ?
2) will it keep the bag dry from extreme humid air from the condensation in the tent in the winter? It does allow air flow after all, so if the air outside is more humid then inside (someting I understand is normal during winter bivouacs), so maybe it makes in difference here?
3) does endurance increase water condensation on the inside of the shell? I had such experiences with a not-to-breathable waterproof sleeping bag.
4) around what temperatures (in the tent) the dew point is expected to be inside the bag? I feel it doesn't have to be that extreme, as I met personally people who had to break their bags because they freezed rigid, without going to arctica?
5) overall, for what conditions would you consider for primary usage of highly water resistant bags, apart from sleeping in snow caves/single wall tents/outside: dry, heavy frost (resulting in heavy condensation in the tent and in the bag), or rather wettish-around-freezing? Or does this question make no sense?
So far, I hadn't have any significant problems with my Quantum bag (and I do live with my crappy 3-season) , but so far I was making mostly single or two-nighters, and I did hear a couple of 'horror stories' involvig condensation and down bags, and before I venture on longer and more demanding winter treks (Carpathians being my goal), I'd like to have full confidence in my bag and understand it's limitations well.
First of all, i've never used my bag for more than 5 nights in a row in winter, so all my comments are based on this.
1) I've never had the down get wet from pressing against wet tent walls. The foot end did get wet once. It was lying in a pool of water, when i was sleeping under a tarp.
2) I've never had the bag get wet from humid air passing through the shell. Endurance might be breathable, but it is very difficult to roll the sleeping bag up from the head end. The air struggles to be pushed out.
3) I've never noticed any condensation on the inside of the shell.
4) I don't know.
5) I think all the conditions you mention are suitable for a water-resistant shell.
My bag is now around 5 or 6 years old, and still performs well. I think the Endurance coating slowly wears off, as it is easier to force air through it now,(Try rolling the bag up from the head end!) and the shell wets out easier, but still doesn't go through to the down.
4) is, I would guess, a function of humidity as well as temperature. Possibly pressure too?
5), well, I sleep in Drilite bags the whole time, because that's my only choice (Dewline and Lightline). And they seem to work well everywhere I've used them so I've never considered I may be better off in something with less water resistance.
Last year I used a VBL with a quilt to keep body moisture out of the down and to reduce drafts. Rationalising this, I'm trialling a homemade down quilt with Cuben inner & outers.
The Cuben keeps drips, condensation and body evaporation off the down ok, giving a light and reasonably durable solution.
There are a few downsides to impermeable coverings, such as Cuben: - Moisture in the air in the down will cool and can still condense in the down, so the outer shell needs vents. To retain splashproofing, I've sewn loose cuben flaps over 2 lines of pertex vents. - As with any VBL, trapped body evaporation leaves one feeling a bit damp. - One needs to judge clothing layers more carefully with a VBL to avoid sweating
The quilt seems to work ok, and an occasional blast of midday sun and wind airs out the down. I think its a useful approach to weightsaving for long distance autonomous trips.
Sounds interesting Judy. Couldn't you put a valve on the quilt, like some pack-sacks and the Exped downmats, and empty and fill the quilt of air as needed. That would also give you a very small pack size. Or is cuben not airtight enough?
Thanks everyone - I'm inclining to a Quantum Endurance, then. Now time to see what's on the market apart from Rab (ideally, I'd like something with more room - 85/55cm). Or maybe you can point some other w/r fabrics?
