Temperature rating of bag for UK use?

Discussion in 'Sleeping Bags & Quilts' started by Foxster, Jul 13, 2019.

  1. Foxster

    Foxster Trail Blazer

    I need a new UL winter sleeping bag and as always when looking at bags, struggle with the numbers.

    The most extreme I camp in is higher spots in the Lakes in February. So not the arctic or high mountain peaks. The question is then just what rating bag should I be looking at?

    I know there are lots of factors like how cold I sleep, what I'm wearing, what mat I'm using, the tent, etc. but what's the ballpark?

    I have a "feeling" around a -7C (comfort rating) bag seems right but could afford a -15 bag, but is that unnecessary weight and cost?

    Two I was looking at today are the Sea to Summit 2019 Spark Sp III (-8C, 660g, £414) https://www.ultralightoutdoorgear.c...c88/2019-spark-spiii-down-sleeping-bag-p11308 versus their Spark IV (-15C, 856g, £489.99) https://www.ultralightoutdoorgear.c...-c88/2019-spark-spiv-down-sleeping-bag-p11309.
  2. Lamont-Cranston

    Lamont-Cranston Ultralighter

    Your gender is also relevant to determine the rating.
  3. Tartanferret

    Tartanferret Section Hiker

  4. Foxster

    Foxster Trail Blazer

    Thanks for the suggestion and that is a bag I looked at. I'm looking for something lighter.

    It's not really a specific bag recommendation I need, it's trying to get a better feel for the comfort rating, which is starting to feel like "How long is a piece of string?".
    Tartanferret likes this.
  5. Baldy

    Baldy Thru Hiker

    i'd er on the side of comfort and go for -10/12.
    cathyjc likes this.
  6. Foxster

    Foxster Trail Blazer

    Just realised there are the usual shenanigans with the two bags I linked in the first post. The numbers they headline are their EN comfort limit ratings. Their more useful comfort ratings are -2C for the III and -8C for the IV.

    So, if these two bags were my final choices (which they aren't) then I'd very likely choose the IV.
  7. Patrick

    Patrick Summit Camper

    I'm guessing this isn't your first bag, so how does your current bag's temperature rating relate to the sort of temperatures you use it in? Although my current bag is rated down to -5 I don't tend to use it much below zero, but that's partly down to the way I like to sleep - don't forget that to take a bag down towards the bottom end of its range you really need to be tightly enclosed in it, hood and shoulder baffles cinched right in. I prefer to be a bit freer than that, and am camping in subzero temperatures rarely enough that it's nice just to know the capability is there if I really need it rather than being something I need to take advantage of all the time. If I was regularly camping at -5 I'd probably want at least a -10 bag, but if you sleep more cocooned by your bag then you might be fine with a warmer rating.
  8. Whiteburn

    Whiteburn Thru Hiker

    The Cumulus Panyam 600 , comfort rating -6C, does me comfortably down to -6 to -7C without doing the hood up & is IMO more generously sized than the PD. Quite reasonably priced too.
    cathyjc likes this.
  9. Foxster

    Foxster Trail Blazer

    The bag I've used for the last couple of winter seasons has a comfort rating of -2C and weighs about 1100g.

    On the last winter outing when I'd say the temp snuck down to -3C or -4C and I was cold overnight. Had to add my midlayer during the night to try to warm up.

    So I definitely need something with a better rating.
  10. Foxster

    Foxster Trail Blazer

    That looks pretty good. Forgot to check them out because they never seem to pop-up on Google searches.

    No large size option. Think it would be OK for a 6'2" (188cm) bloke?

    Just spotted it says "Maximum user height: 190 cm". So I should be good.
  11. Whiteburn

    Whiteburn Thru Hiker

    My guess is the regular would be OK, BUT if you wanted to store gas canisters water bottle at you feet (as I do in winter) it may be a little short.
    Cumulus are quite used to doing 'custom' work (longer, wider, overfilling, etc) best to drop them a line outlining your needs.
  12. Whiteburn

    Whiteburn Thru Hiker

    Missed this new feature: check out their Sleeping Bag Creator should give you what you want :)
    Tartanferret likes this.
  13. Foxster

    Foxster Trail Blazer

    Thanks for that link.

    It all starts adding up though. I chose the L size and hydrophobic down. Price went up to e414, which is not much different from the StS Spark SpIV Long which weighs a little less and has a -2C better temp rating.
  14. Whiteburn

    Whiteburn Thru Hiker

    Temp rating is a bit of surprise as the S2S uses 850 US fill power down & the Cumulus uses 850 European standard which is about 900 US so should be warmer.
    Personally I've never bothered with hydrophobic down, IMO if a SB is wet it's wet doesn't matter whether its hydrophobic or not. From what I understand the benefit seems to be that the hydrophobic may dry out faster.
  15. HillBelly

    HillBelly Ultralighter

    The site you link to has plenty of choices when it comes to bags, so I'd drop them a line for advice.

    I've recently bought a Mountain Equipment bag. I know what you are saying with all the minimum and max ratings, so I liked the nights comfort guarantee from ME which states a single temp down to which you should have a good kip. I know some others do this but have seen enough reviews of ME bags saying they comfortably exceed the EN rating in practice. As do Rab. The ME Firelite is probably about the temp you'd want and a decent weight too.

    I've heard some reports of people not getting anywhere near the stated comfort on some manufacturers bags which are on the lightweight side. I'm sure someone on Treklite has said as much for one of their PHD bags.
  16. Foxster

    Foxster Trail Blazer

    ME bags look interesting but looking closer at the real numbers they don't look so good.

    The Firelite has a comfort rating of just 0C, which for the weight (770g) sounds likely. I know they say you'll get a "Good Night's Sleep" at -9C but that's a £450 risk I'm not sure I'm up for.

    To get a comfort rating with one of their bags similar to others mentioned above you'd need their Xeros, which weighs 1075g and has a comfort rating of -5C. That sounds about right for 605g of 800FP down.

    I've come to the conclusion that a light bag with a comfort rating of around -8C (which should cover the worst UK weather) means an overall weight of 900g to 1000g with 650g (700g for long) of 850+FP down. Get that right and then it's mostly down to extras (hydrophobic down, colour, cover materials) and price, expecting to pay £400 to £500.
  17. Shewie

    Shewie Administrator Staff Member

    Do you carry any insulating clothing layers in winter @Foxster ?

    I’ll carry primaloft or down trews for camp wear on the long nights, they can be used as part of my sleep system along with a decent mat like a XTherm

    I’m still using my old PD600 but the majority of my winter trips are hammock based so I use a 0*f quilt system
    Robin likes this.
  18. Foxster

    Foxster Trail Blazer

    Yup, always have a down mid, which I have slept in before when cold. Thing is, I really don't like sleeping in it and probably wouldn't like trews for the same reason, it feels too restricted. Plus in the winter it is often dampish and brings moisture into the bag.

    Got a new Exped DownMat UL Winter mat to try next winter. I liked my XTherm but got fed up with how slippery it is and struggled to stay atop it. The Exped has a higher R rating than the Xtherm, so that plus a new bag should make me snug as a bug in the proverbial.
    Shewie likes this.
  19. Teepee

    Teepee Thru Hiker

    Winter nights are long. I dont like relying on my sleeping insulation for warmth...it means I'm struggling outside without it.
    So, I tend to not increase the warmth of my sleeping insulation and instead sleep in my insulated clothing. I'll most often sleep in most of my gear except waterproofs. My summer bag gets used all through the winter, only rarely do I take a warmer quilt....and that is rated to -8c comfort (having 3 inches of loft of down).
    Robin and edh like this.
  20. Bob-W

    Bob-W Summit Camper

    The EN13537 ratings *should* be reasonably consistent across manufacturers - after all what's the point in having a standard if it isn't, well, standard. I tend to go with "limit" being for warm sleepers and "comfort" for cold sleepers regardless of gender and work from there.

    Another option is to get something as an outer for your current summer/autumn bag. I use a PHD Minimus 200 bag and a Cumulus 150 quilt combined for winter - both are really only summer rated, from memory they are both rated to around 5C (which I've found accurate and on occasion conservative - sure I've used them slightly nippier than that) but I've used them together at -6/7C just wearing thermals. Their combined weight is c. 800g which when you allow for a redundant second shell of say 150g gives 650g and is around what you'd end up with for a similarly rated sleeping bag: the PHD Minim 400 is rated to -5C and weighs 670g for example. For me, something like the Cumulus 250 quilt would get me in to the -12C sort of territory and I'd be able to use it on its own in early spring or late autumn when it's too cold for the summer bag but not cold enough for the combined bag/quilt.

    Looking around at the better manufacturers, -15C bags are in the 900-1000g sort of range. These will be using 850/900fp down and won't be cheap :speechless: This brings me to another point: just how many nights do you expect to actually use this bag for? The advantage of using a quilt or outer bag is that the kit gets used at other times of year. I've a Rab expedition down bag, rated to -30C, it needs to be -10C or so before I can actually use it - I've had it for over twenty years and used it less than thirty times and only a couple of times in this country. Current list price is £700, those are expensive nights!

    As for wearing down clothing inside your bag: remember that it's you that heats the bag up, wearing a jacket stops that happening. I think it's better to use the jacket as a cover over the top of your bag. I'll wear light thermals, usually merino, which help prevent body oils and sweat contaminating the down. (The test dummy in the EN test is lightly clothed, actually a track/shell suit if I remember correctly).

    Sorry for rambling. HTH
  21. Foxster

    Foxster Trail Blazer

    I think the PHD Minim 400 and it's rating is a pretty good example of the issues with rating numbers.

    That -5C is a manufacturer's claimed rating, it's not an EN rating. It really could mean anything...comfort rating, extreme rating..?

    It's also quite a small bag. A man-sized long+wide+zip custom takes it up to 863g, so around that of other bags in this category.

    Looking at what it's packed with, it's 400g of 800+ FP down. There's no way that is going to match the warmth of other bags with a EN comfort rating around -5C. I'd say at best it's closer to a 0C bag.

    Good points about double bagging and clothing. If you are happy to take a couple of bags or wear padded clothing when tucked in then there likely isn't a need for an expensive winter bag. Especially, as you say, for the amount of use it might get.

    For me though I don't want two bags and I don't like heavy/restrictive clothing when sleeping. So, as is so often the case with gear, it comes down to a personal preference.
  22. Enzo

    Enzo Thru Hiker

    The whole subject is entirely personal by the looks of it.
    The American thru hiker quilts 'rated' at 20f all seem to have ~350g of good down, but assume the use of a puffy.
    My 400g of 850fp EU quilt does me well bellow freezing in just a base layer, though I don't generally bother to get undressed unless I'm muddy or soaked. I've experimented with synthetic overbags and down trousers etc to boost my 3 season quilt. Both work for me, but I'd go down trousers if hiking with others and overbags if fast and lite on my own.
  23. Ally

    Ally Trail Blazer

    Its an industry wide problem i think " lightest sleeping bag ever ", "Lightest tent ever ", its not lying but its pushing honesty to the limit for industrial bragging rites.

    PHD are particularly bad for this, stated weights seem to be for the lightest, least featured version and smallest possible option of each product. Then they get all secretive when any one asks the down weights.

    Terra nova as well with the whole 2g pegs which are utterly useless unless camping on a windless bowling green.

    In regards to the actual question I followed Teepee's advice ( sure he has posted something similar in the past ) for most of this years winter camps. Cumulus 350 quilt year round and add if needed the extra insulation I am carrying any way Cumulus quilt + Rab generator+ hat and fleece liner gloves + xtherm saw me down to -6 and comfortable this year. I'm sure a down jacket and insulated trousers could push it a bit more.
    Teepee likes this.
  24. dovidola

    dovidola Section Hiker

    I think the problem is that the moment an 'industry standard' is introduced, manufacturers find ways to exploit it for promoting their products.
    I look at it pretty much the same way as @Teepee. I know what my Cumulus Quantum 350 is capable of, in conjunction with my various bits of clothing, sleeping mat and tent, both in unzipped quilt mode and in zipped-up bag mode.
    *New Product* Just got back from a few days in the Rhinogs, where all I took for top cover was my newly purchased Therm-a-Rest Proton Blanket (525g, synthetic). Really pleased! I'd say it's good for 10C in conjunction with my standard NeoAir XLite and merino base layers.
    Teepee likes this.
  25. Bob-W

    Bob-W Summit Camper

    I like PHD kit but it does frustrate me that they don't use EN ratings, I'd like to see magazine reviews calling them out on this, it's possibly the only way to get them to change. IME they are the "limit" rating or at least something approximating to it and for me personally they are realistic enough that I trust them. I'd agree about the sizing, I'm 1.8m tall and 83Kg and I find my PHD bag "snug", I wouldn't want to be any bigger or for the bag to be smaller that's for sure. I'm guessing here but I think the 400 in the name "Minim 400" might be the weight of down in the bag, but whether that's the standard bag or one of the variants or an average across the options is anyone's guess. Looks like the headline weight of the Minim 400 is the standard/standard bag, playing around with the configuration options on the Minim 400 page and the weight drops when you choose the short option, etc.

    I quoted a rating above for my Cumulus quilt but again that's just a manufacturer's "guess" as EN13537 only applies to sleeping bags.

    As for manufacturers' claims: well that's the nature of the beast isn't it? I'd love a 400g sleeping bag rated to -30C but cynicism experience tends to indicate that's not going to happen.

    As @dovidola notes, you get to know what a particular bit of kit is capable of when you use it. If the manufacturer states "X degrees", whether that's an EN rating or not, and you are only comfortable to X+3 degrees then you can apply that offset to their other products. I'm not going to quibble about a degree variation - my condition is likely to have as much influence on how I sleep on any given night: kipping on the garden lawn in benign conditions after a day pottering around the house is going to feel very different to one after battling through a Highland hoolie even if the actual meteorological numbers are exactly the same.

    @Foxster - fair enough about doubling up with bags. Just thought' I'd mention it as an option.

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